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These indicators cover the standards and outcomes of treatment given.
CHAI reports 9% readmission as an emergency within 28 days, and assumes that a proportion of the observed readmissions are potentially avoidable.
We conclude that audit should be done as a team-work involving all responsible health care professionals and proper uniform coding system needs to be followed to obtain correct results.
Patient satisfaction was higher in the navigated group and 86% of patients were able to fully mobilize within 72 hours of the index operation.
Computer aided hip arthroplasty may influence postoperative outcome in otherwise uncomplicated surgery. Although the study was limited by non randomization and other variables, initial results are encouraging.
The mean follow up was 21 and 9 months for group A and B respectively.
Final outcome using the Constant and Murley score. The improvement in the score averaged 42 and 47 points in group A and B respectively Early Post operative pain using visual analogue score (VAS) average of 6 and 3 in group A and B respectively Overall patient satisfaction: 81% in group A and 89% in group B.
Patients with IAC who fails to respond physiotherapy and MUA do well after arthroscopic capsular release with little operative morbidity. Complete normal functional outcome of shoulder is not a prerequisite for patient satisfaction.
Between March 2000 and January 2006, 327
1 Intra op fracture &
4 post op fractures. Out of the total number of patients, 131 were above the age of 65years, with mean age of 68.80 years &
a range of 65–77 years. No Femoral neck fractures were found in this age group.
Extraarticular were 10 (40%) of which displaced and undisplaced were 5 each. Fall from height was seen in 20 (80%)patients. Associated injuries was seen in 10(40%) patients of which 8(32%) of them had fracture spine. All the cases of intaarticular fractures had C.T. scan. 5 cases had MUA and pinning for the extraarticular fracture. 8(32%) displaced intraarticular fractures underwent ORIF. 2((8%) intraarticular displaced fractures were treated conservatively. The average follow-up one-year. The final outcome assessed clinical and radiologically. 2 cases of infection, 4 cases of stiffness, 2 cases of deformity seen.1 case had parasthesia.
The final outcome all the fractures treated conservatively were good. Fractures underwent ORIF had better outcome and more complication rate as compared to conservative treatment.
Even the undisplaced intraarticular fractures of calcaneum do develop residual stiffness and difficulty in walking on uneven ground.
Displaced fractures needs fixation for better results and facilitation for secondary operations.
Wound infection, stiffness and deformity are known complications.
In this small audit all three group did develop stiffness and we recommend a bigger, independent audit.
The total of 41 patients were divided into two groups depending on the duration between the primary hemiarthroplasty procedure and its revision to total hip arthroplasty – (1) Less than one year (16 patients) and (2) More than one year (25 patients).
The data collected included: age, sex, classification of the fracture, date of primary operation, surgical approach, inflammatory markers, indication and date of revision to total hip arthroplasty, and the final outcome.
Patients Symptoms Treatment received Spinal Operations Body Diagram for shading the site of pain Final outcome Patient Satisfaction
– 76 patients 66% of the patients who replied “were satisfied” with the surgery. – 38 patients 33% of the patients who replied were not satisfied. – 58 patients did not reply as they were not interviewed.
There were no significant post-operative neurogenic complications, such as cauada equina syndrome or severe leg weakness interfering with standing and walking retirement. There was always a temporary relief followed by deterioration of symptoms after a period ranging between 1–2 years.
Complex proximal humerus fractures have been described as the unsolved fracture. Review of literature shows a variety of treatment methods and results. We present the results of a prospective study of 47 complex proximal humerus fractures treated by PHILOS (Proximal Humeral Internal Locking System) plate. The aim of this study was to assess the effectiveness of the PHILOS plate in the surgical treatment of Neer’s type 3 & 4 fractures.
We operated upon 47 patients (mean age 56yrs) between March 2002 and January 2006 for fixation of 3 part (28 patients) and 4 part (19 patients) fractures at a level 1 trauma centre. An independent observer reviewed patients at 6 monthly intervals for clinical and radiological assessment. Outcome measures included DASH and Constant scores.
42 patients were available for follow up, which ranged from 12–66 (average 24.4) months. Recovery of movements, and relief in pain was satisfactory in most of the patients, but the strength of shoulder did not recover fully in any patient. There were two failures in our series, one due to breakage of plate and another due to non-union; both treated successfully by revision. 4 patients (8%) had radiological signs of avascular necrosis of humeral head but only 2 of them were symptomatic requiring further treatment. Pain due to impingement was noted in several patients leading to removal of plate (6 patients) and subacromial decompression (3 patients). We encountered the problem of cold welding and distortion of screw heads, while removing the plate. The broken plate was subjected to biomechanical and metallurgical analysis, which revealed that the plate is inherently weak at the site of failure.
We concluded that in spite of the above-mentioned complications, the PHILOS plate is a reliable implant to fix 3 and 4 part proximal humeral fractures. We were particularly impressed with the satisfactory results of fixation in 4 part fractures. However, we are not convinced about its strength. The plate may cause impingement in some patients necessitating its removal later on, which itself may not be easy.
For the purpose of this study, the Revision Arthroplasties were excluded.
Amongst Total Joint Arthroplasties, though 10 patients out of 387 had provided positive results for STAA (Staph. Aureus) from swab specimens, none of the patients developed deep infection. But out of 8, who showed MRSA growth from wound swabs, one patient developed deep infection and needed conversion to Girdlestone procedure. Thus the positive results for wound specimens were 18(4.65%), while the re-operation rate was 1(0.26%).
Amongst 137 Hip Hemiarthroplasties, 25 showed positive growths, 7 for STAA and 18 for MRSA. None needed re-operation.
Interesting revelations on misconceptions are revealed!
50 consecutive cases of Scaphoid non-union were treated by open reduction and internal fixation. Average age of non-union was 2.8 yrs ranging fron 6 months to 6 years. Most common approach used was volar. Herbert screw was used to fix 48 non-unions while K wires were used in 2 cases. Bone graft was harvested from patient’s iliac crest and was used in nearly all cases. Wrist was immobilised in a plaster for an average duration of 12 weeks post operatively. All the cases were done by a single surgeon and the cases were recorded by an independent observer.
The average follow up was 2 years ranging from 1 year to 6 years. Radiographic union was achieved in 45(80%) cases. Failure of union was seen in 10 cases out of which 5 were proximal pole fractures of which 2 went into avascular necrosis. Denervation of wrist, proximal row carpectomy and four corner fusion was used in 5 cases to salvage the wrist.
This modest study carried out at a district general hospital of South East England suggests that scaphoid bone continues to be a challenge for general orthopaedic surgeon as some of these fractures are missed initially. Open reduction and internal fixation of Scaphoid non-union continues to give a predictable outcome.
In our unit we noted a number of complications resulting from suboptimal fracture fixations of ankles some of which required revision. It was decided to review fracture fixation of ankles in the unit to see whether the basic principles of fixation was being followed in our DGH.
In every case the fibula fixation did not include a cortical lag screw.
By ensuring that operating surgeons have the appropriate training and experience in basic fracture fixation before being allowed to undertake such procedures, our unit hopes to show an improvement on these figures by the time this audit is repeated.
As management of open tibial fractures remains controversial, we hypothesised that unreamed intramedullary nail offers inherent advantages of a nail as well as external fixation, while limiting the morbidity of external fixation.
We undertook a prospective randomised study to compare management of open tibial fractures with external fixator or intramedullary nail until fracture union or failure. Our study included 30 consecutive open tibial fractures (Gustilo I, II & IIIA) between 4 cm distal to knee and 4 cm proximal to ankle in skeletally mature adults, who presented to a level-1 trauma centre. Alternate patients were treated by external fixation or unreamed nail i.e. 15 in each group. Standard protocol for debridement and fixation was followed. External fixators were removed at 6 weeks. All cases were followed until fracture union, the main outcome measurement.
26 (87%) males and 4 (13%) females; age 20–60 years (Mean 33.8). All fractures in both groups united. Time to union averaged 7.9 months for both groups. Incidence of wound problems, infection, hardware failure and delayed union were comparable. However, there was higher incidence of angular deformities and stiffness of knee and ankle in external fixation group, although not statistically significant.
We found no statistically significant difference between unreamed intramedullary nailing and external fixation for the management of open tibial diaphyseal fractures. Ease of weight bearing as well as absence of angular deformities and joint stiffness were distinct advantages in the nailing group. Therefore we recommend unreamed nail for Gustilo I, II & IIIA open tibial fractures.
We present a case of osteolytic lesion in Gruen Zone 2, 3 in a six-month post-operative cemented THR initially diagnosed as early loosening-?Septic. Investigations and biopsy revealed metastatic renal cell carcinoma.
A 79 year old gentleman had a Left cemented THR and was symptom free post-operative. Six months later he had pain in the left groin and thigh. Examination revealed painless hip movements. X-ray showed lytic area in zone 2 and 3. ESR -90 mm and CRP – 50 mg/dl. Hip aspiration excluded sepsis. Bone scan showed increased uptake of left femoral shaft, right scapula and L1 vertebra. Bone chemistry, renal & liver Assay and tumour markers were normal.
Open biopsy showed erosion of lateral cortex, with friable soft tissue mass with profuse bleeding. Histopathological report showed classical clear cell renal cell carcinoma. CT abdomen and chest revealed multiple nodules in lung fields, multiple nodules in liver, mass in both kidneys consistent with Renal cell carcinoma, multiple skeletal lytic lesions.
Patient was referred to oncologist for palliative treatment
In old age groups Biopsy is recommended to exclude malignancy after exclusion of septic and aseptic loosening and abdominal ultrasound to exclude primaries.
Increased emphasis has been placed on hospital length of stay and discharge planning after total joint arthroplasty. The purpose of this study was to identify patient characteristics and assistance of surgical innovation could reduce length of stay of an inpatient after TJA.
One elderly patient with a fatal intracerebral bleed was found to have justified an early CT scan on the criteria of more than one vomiting episode and a history of unconsiousness.
Four part (Neer’s) proximal humeral fractures if treated by fixation are prone to develop avascular necrosis of humeral head; requiring further treatment and possible reoperation. This has led to the popularity of hemiarthroplasty as the primary treatment in these fractures. Since the availability of contoured locking compression plate (PHILOS) in our unit, we have treated most of the 4 part proximal humeral fractures by internal fixation. The aim of this study was to assess the usefulness of the PHILOS plate in the treatment of these fractures.
We prospectively reviewed 21 patients (mean age 57 yrs) operated between March 2002 and January 2006 at a level 1 trauma centre, using 3/5 hole PHILOS plate for fixation. An independent observer reviewed them postoperatively at 6 monthly intervals for clinical and radiological assessment. Outcome measures included DASH and Constant score. A SPECT/bone scan was done in appropriate cases.
18 patients were available for follow up, which ranged from 12–66 (average 24.4) months. Recovery of movements and relief in pain was satisfactory in most of the patients with mean Constant score of 63 points (range 37 to 95) and DASH score of 20 points (range 15–78) at last follow up.. We encountered a few complications including non-union (1); implant breakage (1) and impingement (4). Only one patient in our series required hemiarthroplasty; out of two who developed symptomatic avascular necrosis. Patient satisfaction was high in spite of moderate Constant score. Removal of PHILOS plate was difficult in some cases due to problem of cold welding and distortion of screw heads. The broken plate was subjected to biomechanical and metallurgical analysis, which revealed that the plate is inherently weak at the site of failure.
Our series is comparatively small to draw any firm conclusions but we feel that with the availability of better implants, there is a case to consider the fixation rather than arthroplasty as the primary treatment of 4 part proximal humeral fractures.
In 4 cases auto graft from iliac crest was used. allograft was not used in any cases. In 12 cases 15 degree hooded insert was used. Average HHS improved from 30 points (range 20–38) to 84 points (range 70–90). Average OHS improved from 24 points (range 18–40) to 82 points (range 74–92). There were no cases of dislocation& infection.1 patient had sciatic nerve neuropraxia.1 case of severe Ankylosing spondylitis failed which was revised.
The PFNA device was developed to address problems of rotational instability in proximal femoral fractures whilst simultaneously employing a single femoral neck element. The PFNA makes use of a helical blade that compresses rather than destroys osteopaenic cancellous bone.
All subtrochanteric fractures admitted to the department were treated with the PFNA (AO 31A3). Demographic and clinical data during admission was recorded and formal post-operative X-Rays performed.
Outcome assessment consisted of a 4 month follow-up appointment with clinical and radiological assessments, VAS, SF36, Jensen Social Function Score and Parker Mobility Score.
From April to December 2006, 46 patients were included in the study. 4 month follow up has been completed in 17 of 23 patients. The average age was 78. 11 short and 7 long nails were inserted. Four patients required open reduction and internal fixation. There were no significant intra-operative or immediate postoperative complications. 1 short nail fractured through the site of the distal locking bolt during the follow up period and required revision.
At follow up, 5 patients had tenderness over the greater trochanter and 2 had leg length discrepancy. None had malrotation. Only 2 patients regained their pre-operative mobility status. The mobility and social function scores were significantly reduced at follow up compared to pre-operative status (p=0.003 and p=0.001 respectively). All domains of SF36 were low compared to normative data. The mean VAS was 3/10.
All fractures united and there was no migration, lysis around or cut out of the helical blade. In total, 25 distal locking bolts were utilised. Four of these had migrated or become loose.
Patients with subtrochanteric fractures do not return to pre-fracture function at 4 months post injury. The PFNA appears to work well although there may be concern about bone hold of the distal locking bolts.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
MRSA infections are a current concern in the elderly orthopaedic patient, with colonisation rates of between 417% reported in these patient groups. In our institution there has been concern regarding MRSA surgical site infection and cross contamination of elective and emergency patients. This prompted the unit to consider a screening programme to identify MRSA carriers. We undertook the following project to assess the feasibility and effectiveness of implementing such a screening programme.
The aim was to to ascertain the incidence of colonisation with MRSA, rate of wound infection and associated risk factors in patients admitted with a fractured proximal femur.
This was a prospective, blinded case series of 100 consecutive patients admitted to the trauma ward with a fractured proximal femur. Three swabs (axilla, nasal and perineum) were taken within 24 hours of admission. Data from each patient was collated and each patient was followed until discharge to assess for surgical site infection.
The age range was 60–97 years. 26% were admitted from institutional care. Four patients were colonised with MRSA on admission. An association was seen between patients colonised on admission and long term or recent residence in institutional care. One of these patients went on to develop colonisation of the surgical wound however this did not lead to surgical site infection and the patient was successfully treated with MRSA eradication therapy only. In these 4 patients all wounds healed satisfactorily with no evidence of infection.
While MRSA continues to be a growing concern in the press we found that rates of colonisation and subsequent infection were not high. There were no documented cases of MRSA wound infection in colonised individuals. Given the cost to detect these low levels of colonisation we do not feel that a screening regime would be cost effective or justified.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
Femoral neck stress fractures (FNSF) are uncommon, representing around 5% of all stress fractures. In military personnel, FNSF represents one of the severest complications of military training, which can result in medical discharge. Clinical examination findings are frequently non-specific and plain radiography may be inconclusive leading to missed or late diagnosis of FNSF. This paper highlights the significance of FNSF’s in military personnel and alerts physicians to the potential diagnosis. We identified all military recruits, aged 17 to 26, who attended the Infantry Training Centre (Catterick, UK), over a four-year period from the 1st July 2002 to 30th June 2006, who suffered a FNSF. The medical records, plain radiographs, bone scans and MRI’s of the recruits were retrospectively reviewed. Of 250 stress fractures, 20 were of the femoral neck; representing 8% of all stress fractures and an overall FNSF rate of 12 in 10,000 military recruits. FNSF’s were most prevalent amongst Parachute Regiment recruits (1 in 250, p< 0.05). Onset of symptoms was most commonly between 13–16 weeks from the start of training. The majority (17/20, 85%) of FNSF’s were undisplaced, these were all treated conservatively. Three FNSF’s were displaced on presentation and were treated surgically. Overall, the medical discharge rate was 40% (8/20). FNSF’s are uncommon and the diagnosis remains a challenge to clinicians and requires a high index of suspicion in young athletic individuals. In such individuals early referral for MRI is recommended, to aid prompt diagnosis and treatment, to prevent serious sequelae.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
High velocity vertical aircraft ejection seat systems are credited with aircrew survival of 80–95% in modern times. Use of these systems is associated with exposure of the aircrew to vertical acceleeration forces in the order of 15–25G. The rate of application of these forces maybe upto 250G per sceond. Upto 85% of crew ejecting suffer skeletal injury and vertebral fracture is relatively common (20–30%) when diagnosed by plain radiograph. The incidence of subtle spinal injury may not be as apparent.
A prospective case series, admitted to QMC Nottingham, from 1996 to 2006 was evaluated. During this interval 26 ejectees from 20 aircraft were admitted to the spinal studies unit for comprehensive examination, evaluation and management. The investigations included radiographs of the whole spine and magnetic resonance Imaging (incorporating T1, T2 weighted and STIR saggital sequences). All ejections occurred within the ejection envelope and occurred at an altitude under 2000 feet (mean 460 feet) and at an airspeed less than 500 knots (mean 275 knots).
In this series 6 ejectees (24%) had clinical and radiographic evidence of vetebral compression fractures. These injuries were located in the thoracic and thoracolumbar spine. 4 cases required surgery ( indicated for angular kyphosis greater than 30 degrees, significant spinal canal compromise, greater than 50% or neurological injury. 1 patient had significant neurological compromise, following an AO A3.3 injury involving the L2 vertebra.
11 ejectees (45 %) had MRI evidence of a combined total of 22 occult thoracic and lumbar fractures. The majority of these ejectees with occult injury had multilevel injuries.
This study confirms a high incidence if spinal fracture and particularly occult spinal injury. Evidently vertical emergency aircraft ejection imposes major insults on the spinal column. Once, appropriately prioritised, life preservation measures have been undertaken, an early MRI of the spne is mandatory as part of comprehensive patient evaluation.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
The conflict in Iraq has evolved from a conventional war in April 2003 to a guerrilla-based insurgency. We investigated whether this change altered the pattern of wounding and types of injuries seen in casualties presenting to a military field hospital.
From January 2006 – October 2006, data was collected on all casualties who presented to the sole British field hospital in the region following injury from hostile action (HA).
86 casualties presented with injuries from hostile action (HA). 3 subsequently died of wounds (DOW – 3.5%). 46 (53.5%) casualties had their initial surgery performed by British military surgeons. 20 casualties (23.2%) sustained gunshot wounds, 63 (73.3%) suffered injuries from fragmentation weapons and 3 (3.5%) casualties sustained injury from blunt trauma. These casualties sustained a total 232 wounds (mean 2.38) affecting an average 2.4 anatomical locations per patient.
The current insurgency illustrates the likely evolution of modern urban conflict. Discrete attacks from improvised explosive devices (IED’s) have become the predominant cause of injury. These tactics have been employed against both military and civilian targets. With the current threat from terrorism, both military and civilian surgeons should be aware of the spectrum and management of the injuries caused.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
The aim of the study was to investigate the attitudes and beliefs of military physiotherapists utilising the ‘Health care providers beliefs attitudes and impairments scale’ devised by Rainville
The HC PAIRS questionnaire was distributed to all 90 military physiotherapists currently serving in a clinical role. The questionnaire was accompanied by a letter explaining that the nature of the study and requesting the questionnaire be completed and that the biographical information of gender, rank, age range, years military service, years physiotherapy experience, qualification to practice as a physiotherapist and highest academic qualification obtained be recorded.
A total of 83 returns were received. Statistical analysis was undertaken using the SPSS (version 14) statistical package. Results indicated a mean score of 50.86(SD 10.189). Military service equated to a mean of 8.86 years (SD 9.153), whilst physiotherapy experience gave a mean of 8.87 years (SD 6.327). Further statistical analysis was undertaken to establish whether there was a correlation between any of the biographical data collected and of the HC-PAIRS score. No correlation of statistical significance was identified in any of the categories.
The results obtained from the military physiotherapists are very similar to those obtained in similar studies utilising civilian physiotherapists, moderately fear avoidant. Attitudes and beliefs would appear to be developed very early in the physiotherapist’s career, exposure to both clinical experience and military culture would appear to have minimal impact on these beliefs. This has important implications when changes to traditional management strategies are being considered and implemented.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
There are well-established guidelines for musculoskeletal and connective tissue disorders in the assessment of potential recruits. There have been no critical appraisals of the application of these guidelines since their recent revision. The aim of this study was to examine whether common presenting conditions are covered by the guidelines and whether there was adherence by the assessor to the recommended outcome. We reviewed 110 potential recruits presenting to an Orthopaedic Consultant. There were a number of conditions not covered and a few occasions when the decision seemed contrary to the guidelines. In particular we think more consideration is needed of congenital deformities.
The femur is the largest and strongest bone with a very good blood supply. Large forces are required to result in a fracture. However once a fracture does occur, there can be significant displacement due to the strong musculature surrounding it and loss of blood. As a result of this, the patients are prone to neurovascular and circulatory compromise, which can lead to significant mortality and morbidity. In an open fracture, there is the added potential for infection.
We have conducted a case review of military patients with femoral fractures sustained in hostile zones admitted to RCDM for definitive treatment.
Retrospective analysis of military patients with femoral fractures admitted to RCDM. Factors to be considered include mechanism of injury, type of fracture (Gustillo Anderson and AO classification), pre- and post-transfer operative treatment, complications, microbiology, length of hospital stay, and discharge status. The presentation will include case discussion of interesting patients.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
Coronal alignment is an important factor in long-term survival of TKA. Many implant systems are available and most aim to produce a posterior slope on the tibial component to reproduce the 70 seen in the normal tibia. We hypothesized that resecting the tibial plateau with a posterior slope can introduce error in coronal plane alignment in TKA.
We used a standard saw-bones model in conjunction with a computer navigation system that is available for use in TKA (Stryker Orthopaedics). The normal protocol for preliminary referencing was followed; care was taken to identify tibial landmarks (tibial plateau reference point, true sagittal plane and transmalleolar axis). We then used a standard extramedullary alignment jig (Scorpio TKR System, Stryker Orthopaedics) with cutting blocks designed to give 0, 3, 5 and 7 degrees of posterior slope and varied the position of the alignment jig.
Variations included:
Medial rotation of the cutting block, Medialisation of the plateau reference point, Mediolateral translation of the distal jig, and External rotation of the distal jig.
In all experiments, there was a greater deviation from ideal coronal alignment as the slope on the tibial cut was increased. The greatest influence was with external rotation of the distal part of the jig, which produced 30 of varus at only 150 of external rotation with a 70 slope. Medialisation of the proximal reference point worsened this to 4.50 of varus.
We have quantified the degree of coronal malalignment that can occur for different posterior slopes during tibial resection for TKA. We recommend either using a minimal slope or navigation to ensure correct implant positioning.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
Cigarette smoking is well recognised as contributing to a higher complication rate following foot surgery. The efficacy of pre-operative counselling to stop smoking has not been evaluated following foot surgery. The purpose of this study was to determine the effectiveness of pre-operative counselling prior to elective forefoot surgery.
A record of smoking status was taken in all patients prior to surgery. Counselling as to the increased complication rate was undertaken by the lead surgeon at the initial outpatient visit and repeated at pre-operative assessment, with patients advised to see their GP for specific strategies and medications. Further smoking history was taken on admission and in review clinics. A telephone survey was then conducted to ascertain smoking patterns following surgery.
Ninety-eight patients underwent forefoot osteotomy or fusion surgery, over an eighteen-month period, by a single surgeon. Of these, twenty-four were recorded as smokers, with follow-up, at a mean interval of twelve months, achieved in twenty-two. Sixteen stopped smoking pre-operatively, with a further four reducing their daily intake as a direct consequence of the counselling. The majority of patients were unaware of the detrimental effects of smoking following foot surgery. Only four patients re-commenced pre-operative smoking patterns following surgery implying long-term behaviour change in the remainder. One complication of a DVT was recorded in a persistent smoker.
This small study has illustrated the benefit of utilizing the pre-operative clinic consultation to educate our patients of the importance of giving up smoking prior to elective surgery. Counselling has been shown to provide an incentive for smoking cessation, which has been maintained after the peri-operative period. Although forefoot fusions and arthrodeses were used to provide the figures in our study, the results are transferable to other branches of foot and ankle surgery.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
Arthroscopy of the ankle and subtalar joints are established techniques in foot and ankle surgery. Arthroscopic ankle arthrodesis is well described and is useful in patients with a poor soft tissue envelope. Subtalar fusion is traditionally an open procedure with potentially significant complications but there is little published on arthroscopic subtalar arthrodesis.
22 patients, made up of 9 males and13 females were operated on from March 2004 to present day with 12 to 36 months follow up. Indications for surgery included primary osteoarthritis and degeneration secondary to previous calcaneal fracture, tibialis posterior insufficiency, neurological conditions and previous ankle fusion. 8 Patients had a concurrent arthroscopic ankle fusion and 4 patients also had a talonavicular fusion.
All patients had surgery by the senior author and followed the same postoperative course. Patients were protected in plaster for 12 weeks with gradual increase to fully weightbearing at 6 weeks and x-rays taken at 6 and 12 weeks. Successful outcome was taken as clinical and radiological evidence of fusion.
21 patients (95.5%) achieved fusion by 12 weeks. There has been 1 nonunion but there have been no wound breakdowns, deep infections or other serious complications.
Previous authors have reported variable complication rates and significant rates of delayed and non-unions following open subtalar fusion. These early results suggest that arthroscopic subtalar fusion is a safe and reliable method with a high success rate and a low complication rate.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
Ankle arthroscopy is generally performed through anterior portals and provides good access to the anterior aspect of the ankle joint. However, the structure of the talus and the anatomical confines of the ankle joint limit access to posterior structures via this approach.
Developments in the technique of posterior ankle arthroscopy have determined the appropriate site for portals with minimal risk of iatrogenic neurovascular injury. This facilitates treatment of conditions such as flexor hallucis longus (FHL) release, excision of os trigonum for posterior impingement, treatment of retro-calcaneal bursitis and treatment of ankle and subtalar joint pathology.
Posterior ankle arthroscopy is a relatively new technique and has recently been adopted by the senior author. This study was performed to explore the benefits and limitations of this procedure and to identify early post operative results.
We describe our experience of this technique in treating 9 patients with varied posterior ankle pathology. 2 patients had excision of os trigonum; 2 had FHL release; 1 had both excision of os trigonum and FHL release; 3 had curettage for posterior osteochondral defect (OCD) of the talus; and 1 had resection of Haglund’s deformity. The mean pre-operative AOFAS scores (Ankle-Hindfoot Scale) was 73 (range 47 to 85). The mean post operative AOFAS score at 3 months was 82 (range 75 to 87). 4 patients had recent surgery and await follow up. There were no complications. Two cases exposed the limitations of this procedure: Incomplete resection of (i) a Haglund’s deformity required conversion to an open excision and (ii) a posteromedial OCD lesion will require further anterior ankle arthroscopy due to inadequate exposure.
We conclude that for the experienced arthroscopic surgeon this is a safe technique that facilitates treatment of a variety of ankle and hindfoot problems that would otherwise require open procedures.
Young active patients with malignant tumours arising in the distal fibula, requiring excision, present a challenge to the treating surgeon. Wide local excision is advocated, to achieve clearance, however, disruption of the ankle mortise results and fusion is often required to restore stability. The loss of movement is poorly tolerated in the younger patient and leads to progressive degenerative changes in surrounding joints.
Excision of the distal fibula lesion followed by harvesting of the proximal fibula and using this graft to recreate the ankle mortise restores ankle stability and retains ankle movement.
Between 1998 and 2007, we have performed this technique on 4 patients. Diagnoses were Ewing’s sarcoma, chondrosarcoma, parosteal osteosarcoma and osteofibrous dysplasia. To date there has been no evidence of distant or local recurrence. One case was complicated by infection, which resolved with radical debridement and antibiotics; the other three fibula grafts survived. Good to excellent results were achieved.
We will present the technical aspects of this procedure, with particular reference to the most recent case, performed on a young female patient with parosteal osteosarcoma.
We believe this technique provides good oncological and functional results and recommend this treatment option is considered in young active patients requiring distal fibula excisions for sarcoma.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
Presentation and subsequent publication has become ‘the holy grail’ of surgical trainees. This perceived importance of presenting work is further reinforced by the fact that over sixty percent of information contained in standard orthopaedic texts is quoted from published abstracts and not full papers. There is concern that increasing reliance is placed on such work and there are calls to restrict the routine use of abstracts in this manner.
This concern is born out of evidence that conversion of presented work into peer-reviewed publication is globally poor throughout the medical specialities.
The purpose of this study is to determine the conversion rate of work presented at the Combined Services Orthopaedic Society into peer review publication.
A Medline search of 81 consecutive published abstracts over six years was carried out. Further cross-referencing was established using Dialog Datastar with a search strategy. The rate of publication of papers presented at these meetings was then compared against other medical specialities across national and international forums.
26 full paper publications were identified. This yields a conversion rate of 32%. This figure is on a par with meetings such as the BOA (35%), the AAOS (34%) and EFORT (40%). It is also a similar level to that seen with work presented at other speciality meetings.
The conversion rate of papers presented at the Combined Services Orthopaedic Society is competitive with other orthopaedic and medical meetings. Overall conversion of presented works to robust literature is poor. Reasons for low publication rates include pressures of time, insufficient planning and disputes amongst colleagues.
In light of increasing pressure on selection of trainees and the perceived need to present work at meetings, this paper reinforces the need for thorough planning when undertaking research & audit and strict acceptance criteria from organising bodies.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
Our study looked at the short and medium-term results of a new and cost-effective method of bone surface preparation and cement introduction. Early failure and loosening of components in knee arthroplasty has been attributed to inadequate bone-cement and prosthesis- cement interfaces, established at the time of surgery. Cement pressurisation and interosseus suction have been shown to achieve effective cement penetration and interdigitation into cancellous bone.
We have devised a technique of cement pressurisation using a modified 20 ml syringe, combined with interosseus suction. Retrospective evaluation of a series of 50 post-operative radiographs of total knee replacements, undertaken without the use of tourniquet, have shown that even and effective penetration of cement to a depth of 8.0 10.6 mm can be achieved consistently using this technique. Evaluation of post-operative radiographs at a minimum of 5 years follow-up showed 16 knees with minor lucent lines about the tibial component with a maximum Knee Society Total Knee Arthroplasty Roentgenographic Score of 2.
In conclusion, we propose that this simple technique of bone surface preparation and cement introduction produces good results in the short and medium term.
Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.
The second case was that of an 11 year old girl who developed cellulitis of the lower thigh, but was not as systemically unwell as the first case. Radiographs again demonstrated osteomyelitis.
Patients normally present with cellulitis, abscesses, boils and carbuncles. However, on rare occasions, more severe invasive infections result, including septic arthritis, bacteraemia or necrotizing pneumonia.
We feel that osteomyelitis caused by PVL positive MSSA is associated with more severe local disease and a greater systemic inflammatory response than osteomyelitis caused by PVL negative MSSA. Treatment is effective but needs to be initiated promptly to prevent significant complications.
Statistical analysis compared relative risks, odds ratios, 95% confidence intervals for relative risk and P values using Chi the squared test.
Average age at diagnosis was 14.9 months. Two had risk factors but had not been screened. Thirty-one hips were dislocated, two were subluxed and one had borderline dysplasia that resolved. Twenty needed open reduction. Sixteen of 22 patients over 1 year at treatment required open reduction compared to 5 of 13 treated age 1 year or less (p = 0.046). Ten had femoral osteotomy, five a pelvic osteotomy, and five both femoral and pelvic osteotomy. There was one postoperative infection.
Eleven cases (68.8%) improved with conservative management and a further three cases improved following a local anaesthetic/steroid injection. Two cases (12.5%) who did not improve with these measures underwent surgical decompression with subsequent improvement in symptoms. No side effects were reported from the either the steroid injection or surgical decompression.
Complete data was available for the full period under review except for the year 2003.
Relapse rate of both treatment methods was compared for all feet in all Dimeglio grades. Relapse rates for Ponseti and surgery respectively were: grade 2, 18.2% vs 0%; grade 3, 36.2% vs 20.4%; grade 4, 35.3% vs 65.4%. The differences were not statistically significant
Kappa scores for the components of the score were 0.403 for the lateral condyle; 0.492 for the trochlea; 0.354 for the proximal radius and 0.508 for the olecranon. Adding item scores to produce a modified Sauvegrain score had an intra-class reliability of 0.858 (95% CI 0.758 to 0.935).
Preparation of the sinus tarsi using hemispherical reamers. Grafting the sinus with a press fit, cortico-cancellous iliac crest allograft, cut with a circular “cookie cutter”. Placing an 8mm titanium cannulated screw parallel to the talo-navicular and calcaneo-cuboid joints.
All patients had a preoperative instrumented gait analysis, video recordings of foot position, AP and lateral weight bearing radiographs.
Patients were encouraged to weight bear as tolerated in a cast at three weeks. Six weeks postoperatively the casts were replaced with ankle-foot orthoses. Gait laboratory reviews were conducted at 3, 6, 9, 12 and 24 months postoperatively with radiological evaluation of the subtalar fusion at 6, 12 and 24 months postoperatively.
Between January 2001 and December 2004, 58 children, mean age 9 years and 4 months underwent bilateral subtalar fusions with the modified technique during multilevel surgery. Fifty-eight patients were reviewed 12 months postoperatively and 54 at 24 months postoperatively.
Deformity correction was uniformly satisfactory. All patients had complete graft incorporation on plane radiographs. No patient required a revision procedure. Six patients subsequently had first metatarso-phalangeal joint fusions for symptomatic hallux valgus.
Bones meet competing demands both structurally and metabolically with an ability to “functionally adapt” to the surrounding environment. Diets high in saturated fat and sucrose (HFS) can adversely affect bone by limiting calcium availability. Conversely, applying a mechanical stimulus, appropriate in magnitude, frequency, and rate has been shown to be osteogenic. Thus, we hypothesized that groups subject to a mechanical loading would incur skeletal benefits, whereas exposure to a HFS diet would adversely affect structural integrity. We also proposed that despite the osteogenic potential of loading stimuli, the calcium-limiting effects of a HFS diet would result in a net decrease in bone structural properties, when considered in combination.
Female mice underwent non-invasive exogenous cantilever bending of the right tibia with a 1Hz trapezoidal waveform for 60s, five days per week, for thee weeks. Loading was calibrated to induce peak strain magnitudes of 1000 microstrain. Mice were randomly assigned to one of two dietary cohorts: high-fat-sucrose (HFS, n=36) or adjusted starch diets (n=36). Mice were further subdivided into groups based on loading status: control, sham, or loaded. Upon sacrifice, tibiae were dissected; morphometrical and mechanical properties were assessed and compared.
Control mice fed a HFS diet had significantly reduced cross-sectional area, cortical thickness, maximal load, and energy to failure when compared to control mice fed the starch diet. No changes in material properties were seen. Mice eating a HFS diet as well as experiencing mechanical loading had significantly greater cross-sectional area, energy to failure, and maximal load when compared to control mice fed a HFS diet, but had reduced structural properties when compared with loaded mice within the starch cohort.
To date, bone structural properties, and not material properties were adversely affected as a result of ingesting a HFS diet. A diet effect was observed, between control mice fed a HFS diet and control mice fed a starch diet, with the former group experiencing the negative affects previously associated with HFS diets in rodents. Presently, a load effect was only observed within the HFS cohort.
Sprains and strains result from collagen fibre overextension. This study investigated changes in the molecular state of collagen due to overextension damage, thereby gaining insight into tissue degeneration and cellular detection of damage. Overextension results in intermolecular and intrafibrillar sliding, detected with x-ray diffraction. Tendon rupture results in increased susceptibility to proteolytic enzymes. These observations and contemporary theory concerning collagen fibre stability lead to the hypothesis that sub-rupture overextension should result in reduced thermal stability of fibrous collagen.
Tendons were harvested from steer tails. Each provided a specimen for control and for overextension. Sub-rupture overextension at 1%/s strain rate was accomplished on a mechanical testing system, under the control of custom software, until the slope of the force-deformation curve was approximately zero (before complete failure). Two loading treatments were tested: one-cycle and five-cycles. Two specimen types were tested: native tendons ± NaBH4 crosslink stabilization. Tendons in each of the four groups (2x2) were paired by originating tail. Thermal stability was assessed in terms of denaturation temperature (Td) using hydrothermal isometric tension testing. Specimens were held at constant length and heated from ambient temperature to 90degC. Td was defined as the temperature where load suddenly increased due to molecular unraveling and attempted shrinkage.
Overextension of native specimens reduced the thermal stability of the collagen (p< 0.0001) and five-cycles had a still greater effect (p=0.03). Td of controls was 64.5±1.0degC (mean±SD). After one-cycle, Td dropped to 63.2±1.0degC and, after five-cycles, Td dropped to 61.8±2.0degC. For stabilised tendons, the effect of multiple cycles was lost (p=0.08) but overstretching decreased Td by ~2degC (p< 0.0001).
This study confirms that the molecular state of collagen is altered by overextension damage, reducing Td by up to 10% of the expected range (37–65degC) in our experiments. This is thought to occur due to intermolecular sliding that liberates specific domains on the molecules, lowering the activation energy for uncoiling. These domains may also be key targets in degeneration and cell-collagen signaling.
The purpose of this study was to develop a cell-based VEGF gene therapy in order to accelerate fracture healing and investigate the effect of VEGF on bone repair in vivo.
Twenty-one rabbits were studied. A ten millimeter segmental bone defect was created after twelve millimeter periosteal excision in the middle one third of each tibia and each tibia was plated. Primary cultured rabbit fibroblasts were transfected by use of SuperFect (Qiagen Inc) with pcDNA-VEGF. 5.0 X 106 cells in 1ml PBS were delivered via impregnated gelfoam into the fracture site. Experimental groups were:
Transfected fibroblasts with VEGF (n=7), Fibroblasts alone (n=7), and PBS only (n=7). The animals were sacrificed and fracture healing specimens collected at ten weeks post surgery
Radiology: Fracture healing was defined as those with bone bridging of the fracture defect. After ten weeks, fourteen tibial fractures were healed in total including six in group one, four in group two and four in group three. The VEGF group had an earlier initial sufficient volume of bridging new bone formation. Histological evaluation demonstrated ossification across the entire defect in response to the VEGF gene therapy, whereas the defects were predominantly fibrotic and sparsely ossified in groups two and three. Numerous positively stained (CD31) vessels were shown in the VEGF group. MicroCT evaluation showed complete bridging for the VEGF group, but incomplete healing for groups two and three. Micro-CT evaluation of the new bone structural parameters showed that the amount of new bone (volume of bone (VolB) x bone mineral density (BMD)), bone volume fractions (BVF), bone volume/tissues (BV/TV), trabecular thickness (Tb.Th), number (Tb.N) and connectivity density (Euler number) were higher; while structure model index (SMI), bone surface/bone volume (BS/BV), and trabecular separations (Tb.Sp) were lower in the VEGF group than the other groups. P-Values < 0.05 indicated statistical significance (ANOVA, SPSS) in all parameters except for SMI (0.089) and VolBx-BMD (0.197).
These results indicate that cell-based VEGF gene delivery has significant osteogenic and angiogenic effects and demonstrates the ability of cell based VEGF gene therapy to enhance healing of a critical sized defect in a long bone in rabbits.
We sought to establish whether fibroblasts transfected ex vivo could be delivered via gelfoam impregnated with a solution of transfected cells to achieve local transgene expression in a fracture site.
A 10 millimeter segmental bone defect was created after 12 mm periosteal excision and plated in the middle one third of each rabbit tibia. Dermal tissues were obtained and fibroblasts were cultured with DMEM. Fibroblasts were labeled with CMTMR and 5x106 labeled fibroblasts in 1ml PBS with 1x1 cm? Impregnated gelfoam was placed into the fracture gap (n=2). Twenty four hours after cell injection, the rabbits were killed and specimens were harvested from the fractured leg. Using SuperFect (Qiagen Inc), the primary fibroblasts were transfected with pcDNA-VEGF which was generated with the full length coding sequence of the human VEGF gene. A convenient reporter gene, Efficiency Green Fluorescent Protein (EGFP), was used for monitoring transfection of VEGF by fluorescence intensity. Experimental rabbits received 5.0 X 106 VEGF transfected cells in 1 ml PBS via gelfoam at the fracture sites. The animals were sacrificed at seven days (n=4), fourteen days (n=4) and twenty-one days (n=4) post surgery and the fracture site specimens were collected for analysis.
The fluorescently labeled cells with CMTMR were found at the fracture site and surrounding tissues. It was demonstrated that the labeled cells were delivered into the fracture gap, bone marrow and muscle surrounding a segmental defect in the rabbit. In the VEGF group, visualised VEGF immunostaining (brown) was shown in the fracture site around the Gelfoam; as well VEGF was distributed at sites of endochondral ossification. Visible bone formation was shown: VEGF promoted new bone formation by VonKossa staining (dark) and produced numerous vessels by CD31 positive staining (brownish black). The VEGF protein was detected in and around the fracture by ELISA.
This data encourages the further development of genetic approaches using cell based VEGF gene transfer without viral vectors to promote fracture healing.
The hypothesis is that cells isolated from capsules of joints with contractures will contract collagen gels at a faster rate when compared to cells obtained from capsules of joints free of contractures.
Post-traumatic joint contractures were produced by removing cortical bone windows from the femoral condyles of three skeletally mature rabbits and immobilizing the knees for four weeks with a K-wire. The contralateral knees served as an unoperated control. At sacrifice, the posterior capsules were immediately placed in medium and the tissue was minced. Upon confluence, cells were trypsinised and gel contraction studies were carried out on passage four cells. Five x 105 cells/ml were mixed with 58% neutralised bovine collagen solution and five hundred microlitres of collagen gel/cells solution were then cast into wells of a tissue culture plate. Gelation occurred overnight at 37C in a humidified incubator containing 5% CO2. At cultured day zero, day one, day three, the gels were released from the well walls. The areas of the gel were measured using an image analyzer immediately after release (zero hour), and one hour, two hour, three hour and four hour post-release.
The amount the collagen gels were contracted depended on the time of preincubation of cells and collagen before release and the source of the joint capsule cells. In general, increasing the time of preincubation heightened the contractile response of the cells. The collagen gel contraction was small for the day zero groups over the first four hours, but for the day three groups the rate of contraction was markedly increased. In all cases the collagen gel contraction was larger for the contracture capsule cells when compared to the control capsule cells. The patterns of the contraction over the four hours post release were similar for contracture and control groups.
Cells from capsules of joints with post-traumatic contractures have intrinsically heightened in vitro contractile properties when compared to normal cells. Future work will determine whether the response is exaggerated to fibrotic stimuli such as TGF-beta1 in these capsule cells from post-traumatic joint contractures.
Evidence suggests that femoral neck fractures initiate in the superolateral cortex, where it is significantly thinner in older than younger individuals (Mayhew, et al. Lancet 2005). Thus, we sought to determine the relative time-course of crack initiation and propagation during a simulated hip fracture.
Four unembalmed frozen, human cadaveric specimens (mean age = 78 yrs) were loaded to failure in sideways fall configuration at a rate of 100 mm/sec using a materials testing system. Images of the fracture were captured with two high-speed video cameras at a resolution of 384x384 pixels, and sample rate of 9,111 Hz (frames/second).
Test A: The load-displacement (L-D) curve had three distinct peaks: at the first peak (4390 N), the head and neck rotated slightly. At the second peak (4607 N), a visible local compressive fracture appeared in the superior cortex of the proximal neck. At the third peak (3582 N), a neck-spanning tensile failure occurred in the inferior neck. Test B: At the first and second peak loads (1714 N and 3040 N) fluid was released from the posterior then superior and inferior surfaces. The third peak load (3361 N) corresponded to a local compressive failure in the lateral superior neck, followed by a neck-spanning tensile failure medially. Test C: The L-D curve was linear until ultimate load (3038 N). A compressive crack first appeared on the anterior-superior surface of the neck cortex, then fractured in the inferior neck. Test D: The L-D curve was linear until ultimate load. A small local crack appeared in the superior cortex of the proximal neck at ultimate load (3841 N).
We found that during ex vivo simulations of hip fracture, the femur failed initially in the superior cortex of the neck, and then failed in the inferior cortex. This is the first study to demonstrate, with high speed video data, the location of crack initiation and its propagation. These preliminary data support the hypothesis of Mayhew et al. (Mayhew, et al. Lancet 2005) in terms of fracture development and could relate to clinically relevant fracture types.
Current research strategies for studying articular cartilage (AC) repair include the observation of chondrocyte behaviour in monolayer cultures, the use of artificial matrices and animal models. Since AC relies on the diffusion of joint synovial fluid for nourishment, we hypothesised that it should be possible to develop a research model in which full-depth AC explants are maintained under established tissue culture conditions. Successful maintenance of explants for prolonged periods of time would represent a novel approach and provide a very powerful research tool to address a wide range of chondrocyte biology and matrix synthesis questions. The objective of the project was to examine the cell viability within an AC explant model maintained in tissue media.
AC samples were obtained from the femoral condyles of total knee arthroplasty patients. Cylindrical dowels (10mm in diameter) were harvested from these samples. The dowels consisting of full-depth AC with several mm of subchondral bone attached were placed in tissue culture flask (T-25) containing 15mls of the respective culture media and maintained at 37oC in an incubator containing 5% CO2. Dowels were cultured in a variety of different media formulations (DMEM/F12, CGM (chondrocyte growth medium)) as well as PBS (phosphate buffered saline) which served as a negative control. AC chondrocyte viability was evaluated after five weeks. After having determined the best medium for cartilage maintenance, a second study with a broader range of end-points was undertaken. All dowels collected, rated 2/4 on the Outerbridge scale for osteoarthritis, and were then grown for zero, four, eight or twelve weeks in DMEM/F12 and CDM (chondrocyte differentiating medium). At each time interval, the dowels were evaluated for viability (live/dead stain), general morphology (trichrome stain), distribution of matrix proteins and proteoglycans (aggrecan, Types I and II collagen – immunofluorescence).
After five weeks in PBS, there were no viable cells in the explant. Viability in the explants maintained in DMEM/F12 was 71% compared to 59.6% in the CGM treatment. The viability of the cells in the second study was 90% with DMEM/F12. After twelve weeks, the explant models stained well for general morphology and the distribution of proteoglycans and collagen was well maintained.
To our surprise, the DMEM/F12 medium actually demonstrated the highest cell viability. Typically, AC requires joint motion to pressurise the synovial fluid into the matrix, which augments the transport of nutrients to the cells. Given that this study did not include any form fluid pressurization, it is surprising that such high cell viability was observed. This suggests that passive diffusion alone may provide adequate nourishment in this model system. In conclusion, the explant model for studying AC damage and repair examined in this research appears to be quite promising. This novel approach may serve as the foundation for subsequent research into new treatment strategies for AC injury.
The purpose of this study was to examine the interactive effects of diet and the aging process on the mechanical and material properties of bone. We investigated how an ad libitum (AL) diet and 40% caloric restriction (CR) with nutrient supplementation, beginning at 3.5 months of age, interacted with the aging process to influence bone development. Diet effects were determined by measuring changes in bone geometry and bone mechanics of the tibia in young adult and senescent Fischer 344 X Brown-Norway Rats (F344 BN) rats.
Male F344 BN rats were divided into two dietary groups, AL or CR. CR commenced at 14 weeks of age, with 40% restriction and micronutrient supplementation. The AL group represented young adult (8 mo) and senescent (30–35 mo) rats. The CR group represented 8 mo and 35–40 mo rats. AL and CR groups were matched together for comparison based on the percentage survival rate. Tibiae were assessed using microcomputed tomography, mechanical testing, and ash analysis.
The results showed that a CR diet resulted in a significant decrease in total body mass when compared to the AL diet group across all ages. With aging, both AL and CR diet groups showed a general increase in structural properties and a decrease in material properties. Furthermore, material and structural properties changed proportionately between both diet groups. Comparisons between diet groups based on percentage survival rate revealed a significant decrease in most structural properties, but no significant changes in material properties with CR. After normalization to body mass, structural properties were significantly greater in the CR group when compared to the AL group.
The significantly greater CR structural properties over the AL diet group after normalization, with no significant changes in material properties, indicated that CR did not adversely affect the appendicular skeleton in F344 BN rats. Therefore, a CR diet with 40% restriction at fourteen weeks, with nutrient supplementation did not negatively impact tibial geometrical and mechanical properties in young and senescent male F344 BN rats.
Effective cryopreservation of articular cartilage (AC) could improve clinical results of osteochondral allografting and provide a useful treatment alternative for large cartilage defects. Vitrification (a form of cryopreservation) incorporates high concentrations of cryoprotectant agents (CPAs) and rapid cooling rates to preserve cells in suspended animation without detrimental ice formation. Effective vitrification requires high concentrations of CPAs within the cartilage matrix but the time-dependent toxicity of CPAs hinders their usefulness. The objective of this experiment was determine the CPA permeation parameters for four commonly used CPAs. This data will enable the use of mathematical models to develop novel vitrification procedures to preserve AC. We hypothesised that the time dependency of CPA permeation into intact AC can be determined by exposing AC to CPAs for specific times and then allowing the CPA to be removed into a known volume of PBS, the osmolarity of which is then measured.
Full thickness 10mm diameter osteochondral dowels were harvested from the medial femoral condyles of sexually mature pigs. The dowels were randomly immersed in one of four CPAs (DMSO, propylene glycol, ethylene glycol, and glycerol) for various lengths of time (1–15 min). The cartilage was then immersed in 4ml of 1X PBS in a sealed container for twenty-four hours. The equilibrated solution was measured for osmolarity. The cartilage was weighed before and after treatment and this data was used to calculate the CPA concentration within the AC. This will be repeated in triplicate.
Preliminary results (minimum n=2) indicated a marked difference in permeation for the four CPAs. Ethylene glycol had the most rapid permeation with almost complete permeation (84%) within 15 min. Conversely, glycerol had the least permeation (29%) after 15 min most of which occurred within the first minute. DMSO (63%) and propylene glycol (40%) had intermediate rates of permeation that gradually increased over time.
Cryoprotectant agent permeation into intact porcine AC can be calculated using the method described in this study. This will allow us to successfully document the permeation kinetics of four commonly used CPAs within intact AC. This valuable data will markedly improve our ability to create novel vitrification solutions using mathematical models to add and remove CPAs to limit their toxic effects at high concentrations.
Articular cartilage (AC) has a poor innate healing capacity following significant injury. Autologous chondrocyte implantation is a repair technique which utilises in vitro-expanded chondrocytes combined with a periosteal patch. The chondrocytes are enzymatically digested from arthroscopically harvested tissue at an initial surgery and expanded in monolayer culture prior to implantation at a second procedure. Unfortunately, in vitro expanded chondrocytes appear unable to retain their fundamental phenotype resulting in dedifferentiated cells which produce a matrix of inferior quality. This study compares the matrix-component gene expression profiles of chondrocytes in their native chondrons and through multiple divisions in monolayer culture. We hypothesised that there would be a rapid decline of matrix-component gene expression within a few cell replications in monolayer culture. The goal is to understand more fully the process of chondrocyte dedifferentiation and to compare matrix-component gene expression during cellular expansion in vitro.
Human AC was obtained from tissue donors and operative patients. A portion of the AC was stored at −80°C for use as a control while the remainder was homogenised and enzymatically digested with collagenase. The released cells were plated in monolayer culture and passaged (2:1) when they approached confluence. RNA was extracted from the frozen cartilage control and the passaged chondrogenic cell lines from which cDNA was generated. Real time PCR was performed with primers specific for collagen I, collagen II, aggrecan, and GAPDH. Gene expression was quantified and profiles from the cells in their native chondron and passaged cells (p0-p9) were compared.
Cells, when removed from the extra-cellular matrix and plated in monolayer, experienced an immediate upregulation of collagen I which persisted throughout all passages. In contrast, there was a stepwise decrease in collagen II with each successive passage until p8-p9 when the expression became undetectable. Aggrecan expression only decreased minimally as the cells were passaged.
Rapid dedifferentiation of monolayer cultured chondrocytes is a persistent barrier to AC tissue engineering including ACI. This study quantified the expression of relevant genes relating to AC generation and is an important first step to understanding cellular events, as alternative expansion techniques and cellular alternatives are sought.
To evaluate the mechanism by which orthopedic implant wear particles induce apoptosis in immature osteoblasts in an in-vitro setting.
Stromal cells from femurs of thirty day-old Swiss Webster Mice were isolated, cultured in-vitro, and incubated with orthopedic wear particles in the micrometer size range. After incubation with wear-particles, the cells were assessed for Caspase three expression and activity in the presence or absence of specific inhibitor(s) in order to delineate potential mechanism for cellular changes previously reported.
Here we report the induction of caspase three protein expression and activity with incubation of stromal cells with titanium wear particles. Caspase three activity however was not demonstrated to be up regulated in a time dependent manner or at lower concentration of particles (2 x 107 particles/ml). However, there was a significant (P< 0.05) increase in caspase three activity with titanium particle at higher concentration (4 x 107 particles/ml) that was not reversible when the extrinsic arm of the apoptotic pathway was blocked with anti-TNFƒa antibodies.
Our previous studies have suggested that aseptic loosening of orthopedic implants may be independent of inflammatory processes, and may be associated with induction of programmed cell death. Our current results would strengthen this idea by demonstrating induction of expression and activity of caspase three involved in apoptosis in cells incubated with wear particles. In addition, titanium wear particles may induce apoptosis through direct cellular effects rather than through the extrinsic TNFƒa pathway. Delineating the mechanism by which wear particles induce apoptosis in immature osteoblasts will allow for the selection and/or development of inhibitors to the process of asceptic loosening by targeting a specific pathway.
The hypothesis is that mast cell numbers and neuropeptide containing nerve fibres are increased in the elbow joint anterior capsule of patients with post-traumatic contractures when compared to normal capsules.
Capsules were obtained from two patients with chronic contractures following radial head fractures and two organ donor elbows free of contractures. Four sections from each capsule were double-labelled with specific antibodies to the mast cell marker chymase and the neuropeptide calcitonin gene-related peptide (CGRP). Species specific secondary fluorescent antibodies were used to detect the marker antibodies and cells were identified with a fluorescent nuclear marker (DAPI). Images were captured using a microscope (200x magnification) and five randomly selected areas were sampled for each section obtained from all joint capsules. Chymase positive cell numbers and numbers of nerve fibers (minimum length fifty micrometres) were gathered.
The number of chymase positive mast cells was 6x greater in the contracture capsules when compared to normal capsules. In the contracture capsule, chymase positive mast cells represented 39% of total cells while in control capsules they represented 7% of total cells. Total cell numbers were similar in the capsules of both groups. The number of CGRP positive nerve fibres was increased 3x in the contracture capsule when compared to normal capsule.
Mast cell numbers and neuropeptide positive fibre numbers are increased in the elbow joint anterior capsule of patients with post-traumatic contractures when compared to normal tissues. Neuropeptides such as CGRP can induce mast cell degranulation. Mast cells release profibrotic molecules such as transforming growth factor beta1 (TGF-b1), a myofibroblast upregulator. It has been described that TGF-b1 and myofibroblast numbers are elevated in human elbow joint capsules in post-traumatic contractures. While these trends are encouraging, more subjects are needed to determine whether the mast cell and neuropeptide nerve fibre findings can be generalised to larger numbers. If future work supports a myofibroblast - mast cell - neuropeptide - fibrosis axis in the joint capsule in post-traumatic contractures, then methods to modulate this axis, such as mast cell stabilisers, may be evaluated in animal models.
The purpose of this study was to characterise the neuromuscular patterns associated with different severities of knee osteoarthritis (OA).
Forty-five patients with moderate OA, thirty-seven with severe OA and thirty-eight asymptomatic controls underwent a complete gait analysis with only the electromyographic (EMG) findings presented in this abstract. Severity levels were established through the Kellgren-Lawrence radiographic grading system, functional ability, and those classified with severe OA were tested within one-week of total knee replacement surgery. All OA patients had medial joint involvement. Subjects walked along a five-meter walkway a total of five times at a self- selected walking speed. Muscle activation patterns of the vastus medialis and lateralis, medial and lateral hamstring and medial and lateral gastrocnemius were recorded and normalised to maximum voluntary isometric contractions. All EMG waveforms were analyzed for group differences using PCA [1] followed by an ANOVA (group by muscle) for the PCA scores for each muscle group. These scores reflect both magnitude and shape changes.
The control group was significantly younger (53.3 ±9.5 yrs) and lighter (77.5 ±14.5 Kg) than the patient groups (Moderate =59.8 ±8.0 years and 94.2 ±19.2 Kg and Severe = 63.1 ±7.9 yrs and 95.8 ±14.6Kg). The severe OA group walked significantly slower (0.9 ±0.2 m/s) than the asymptomatic (1.3 ±0.1) m/s) and the moderate OA (1.2 ±0.2 m/s) groups. The PCA analysis of the EMG waveforms revealed statistically significant differences (P< 0.05) in patterns among the three groups and between muscles within the three muscle groups tested.
The neuromuscular differences found among groups during gait demonstrate that the role of the musculature surrounding the knee is altered slightly in those with moderate OA and altered drastically in those with end-stage OA compared to asymptomatic subjects, reflecting a progression. The differences are consistent with the severe group adopting a co-activation strategy of agonist and antagonists, more lateral activation and a reduction in plantar flexion during push off. These are consistent with strategies to increase dynamic stability and reduce medial joint loading. The moderate OA group illustrates a trend toward adopting this pattern but with only very subtle differences from asymptomatic subjects as has been previously reported. These neuromuscular alterations have implications with respect to muscle function and may assist in defining severity.
This study examined the effect of wrist fracture deformities on the work and kinematics of forearm rotation in vitro.
An osteotomy was performed on eight fresh frozen upper extremities just proximal to the distal radioulnar joint and a three-degree of freedom modular implant designed to simulate distal radius fracture deformities was secured in place. This allowed for accurate adjustment of dorsal angulation, dorsal displacement, and radial shortening. The study was divided into two parts, the first phase examining the effects of distal radius deformity and the second sectioned the TFCC and repeated the testing, reviewing the effects of a progressive soft tissue injury in conjunction with distal radius deformity.
The magnitude of muscle activity required to achieve the motion, namely the work of rotation, was affected by the degree of simulated malunion and whether the TFCC was intact or sectioned. Increasing dorsal angulation caused a significant reduction in forearm pronation and supination. Once the TFCC ligaments were sectioned, the range of motion was restored to the pre-injured state for both pronation and supination. Dorsal displacement decreased the forearm range of motion significant at 10mm from native (p=0.02) and 5mm (p=0.03) for intact pronation. Radial shortening of 5mm or less had no effect on forearm rotation. However, 7.5mm of radial shortening could not be achieved in any of the specimens until the TFCC was divided.
Our results reveal that a significant loss of forearm rotation can be expected if a radius fracture exceeds thirty degrees dorsal angulation or 10mm of dorsal displacement. Radial shortening greater than 7.5mm could only be achieved concomitant with a TFCC rupture. This and further study in this area, should assist clinicians in developing treatment strategies for their patients with fractures and deformities of the distal radius.
Determine the association between net external knee adduction moment (KAM) characteristics and foot progression angle (FPA) in asymptomatic individuals and those with moderate and severe osteoarthritis through discrete variable and principal component analysis (PCA).
Fifty-nine asymptomatic (age 52 ± 10 years), fifty-five with moderate knee OA (age 60 ± 9 years) and sixty-one individuals with severe knee OA (age 67 ± 8 years, tested within one week of total knee replacement surgery) participated. Three-dimensional (3D) motion (Optotrak) and ground reaction force (AMTI) data were recorded during gait. Subjects walked at a self-selected velocity. The KAM, calculated using inverse dynamics was time normalised to one complete gait cycle. FPA was calculated using stance phase kinematic gait variables. The discrete variable, peak KAM, was extracted for the interval (30–60%) of the gait cycle. PCA was used to extract the predominant waveform features (Principal Components (PC)) of which PC-Scores were computed for each original waveform. Pearson Product Moment Correlations were calculated for the FPA and both the PC-scores and peak KAM. Alpha of 0.05 used to test significance.
No significant correlations were noted for the groups between peak KAM and the FPA, or for the first PC-Scores (PC1) of which captured the original KAM waveforms overall magnitude and shape. The second PC (PC2) captured the shape and magnitude during the second interval of stance (30–60%) with respect to the first. Correlations of FPA to PC2 were significant for the asymptomatic group(r=−0.40, p=0.002) and the moderate OA group (r=−0.32, p=0.017) but not for the severe group(r=−0.13, p=0.316).
No relationship between FPA and peak KAM was found across the groups using discrete variable analysis despite reports of associations in asymptomatic subjects. The PCA results suggest a toe out FPA was moderately correlated to a decreased KAM during 30–60% of the gait cycle for asymptomatic and moderate OA individuals only. These individuals respond to a toe out progression angle, altering the KAM which directly affects medial knee compartment loading, where those with severe OA do not.
This study determined the inter-reader and intra-reader reliability of lower limb frontal plane alignment measures obtained from digital radiographs using a computer software program.
Measurements of lower limb frontal plane alignment were obtained from over 3000 full limb digital radiographs of both limbs of persons ‘at risk’ for developing knee osteoarthritis (OA), as part of the Multicenter Osteoarthritis Study (MOST). Three trained clinicians used a computer software program (Horizon Image Viewer, version 1.5, OAISYS Medical Inc.) to locate bone landmarks on the femur and tibia from which standard measures of alignment (e.g. the Hip-Knee-Ankle (HKA) angle) and bone lengths could be computed.
To assess the reliability of these alignment measurements, one hundred randomly assigned digital radiographs, representing two hundred limbs, were selected from the complete data set for a repeated analysis carried out two or more weeks after completion of the first measurements. Random effects two-way analysis of variance (ANOVA) models were applied to estimate the interclass and intraclass correlation coefficients (ICC), which correspondingly evaluated inter-reader and intra-reader reliability for each of the angles and bone lengths.
High reliability measures were obtained for the HKA angle (inter-reader reliability: ICC=0.995 (95% CI, 0.994–1); intra-reader reliability: ICC= 0.998 (95% CI, 0.998–1)). Reliability for additional angles between the femur and tibia ranged from 0.839 to 0.993 (inter-reader reliability) and 0.908 to 0.998 (intra-reader reliability). High reliability measures were also obtained for bone lengths (inter-reader reliability: ICC from 0.993 to 0.995; intra-reader reliability: ICC from 0.994 to 0.995).
Each of the lower limb alignment and bone length measurements were highly reliable. The outcome supports the use of computer software programs and software tools for analysis of lower limb frontal plane alignment.
Create an optimization model of the internal structure of the knee joint to quantify the correlation between external knee adduction moment (M[add]) during gait with the medial-to-lateral ratio of compartment loading (MLR). Patients were examined the week before, and six months after, surgical knee joint realigment with a high tibial osteotomy (HTO).
Thirty patients (six females, twenty-four males; age = 50.0 ± 9.4 yrs.; BMI = 30.0±2.8) with clinically diagnosed OA primarily affecting the medial compartment of the knee underwent a medial opening wedge HTO. Walking gait analysis was performed immediately pre-surgery and at six months post-surgery using optical motion analysis (eight Eagle camera EvaRT system, Motion Analysis Corp, Santa Rosa, CA, USA) and floor-mounted force plate (OR6, AMTI, Watertown, MA, USA). External joint kinetics were calculated using inverse dynamics. Kinematic and force plate data served as input for the internal knee joint model. The anatomical geometry was generic but scaled to patient height and knee alignment. Included were four ligaments (ACL, PCL, LCL, MCL), two contact surfaces (medial and lateral) and eleven muscles (quadriceps, hamstrings, gracilis, sartorius, popliteus and gatrocnemius). A loading solution was found to satisfy mechanical equilibrium and minimise the sum of squares of all structural loads. Output was the ratio of medial-to-lateral compartment compression (MLR). Paired t-tests compared M[add] pre-op versus post-op and MLR pre-op versus post-op. A Pearson R2 coefficient of determination was calculated correlating M[add] to MLR for the pre-operative condition.
Peak M[add] decreased from 2.53 ± 1.32 to 1.63 ± 0.81 [%body weight*ht] (p< 0.001). The peak MLR decreased from 2.63 ± 1.08 to 1.52 ± 0.56 [unit-less] (p< 0.001). There was a moderate correlation between M[add] and MLR with the Pearson R2=0.457 (p=0.014).
These results suggest that adduction moment is an acceptable proxy for quantifying the internal compressive loading in the knee. Even without considering muscle loading and possible co-contraction of antagonists, adduction moment explains nearly half of the variance in the internal loading of the knee joint compartments. However, further research is required with a larger sample size to increase confidence in this proxy measure in a clinical setting.
The knee adduction moment is indicative of the degree of medial compartmental loading at the knee joint and has been related to the presence and progression of knee osteoarthritis (OA). Studies have reported differences between OA and asymptomatic groups when measuring the adduction moment at the knee; however, there have been various biomechanical models used to describe this moment. In addition, non-invasive interventions have been shown to decrease the adduction moment but only at certain portions of the gait cycle. The objective of the study was to determine if changing the biomechanical model would affect the ability to detect differences between OA and asymptomatic gait and whether these differences depended on which portion of the gait cycle was analysed.
The gait of forty-four asymptomatic and forty-four moderate OA subjects was measured. The adduction moment was calculated using three different biomechanical models commonly used in the literature:
a 2D representation of the lower limb, a 3D coordinate system based in the tibia, and a 3D coordinate system based in both the tibia and femur. The adduction moment waveforms were compared between groups for various portions of the gait cycle for all three models.
The choice of biomechanical model changed the overall magnitude and shape of the adduction moment waveform. These changes affected the ability to detect group differences using commonly reported parameters of the adduction moment. However, group separation was achieved (regardless of model) when analyzing the overall magnitude of the adduction moment across stance phase and the mid-stance portion of the gait cycle.
These results demonstrate that the OA subjects are not unloading the medial compartment of the knee at full weight acceptance as well as the healthy controls. Furthermore, the OA subjects are experiencing a higher medial compartment load that is being sustained for the duration of the stance phase of the gait cycle. Group differences that are not model dependent may be important in understanding the pathomechanics of OA and evaluating interventions. These findings support the need for a better understanding of the anatomical mechanisms associated with the adduction moment.
Optical motion analysis (MA) is a useful tool for evaluating musculoskeletal function in health and disease. MA is particularly useful in quantifying joint kinematic and kinetic abnormalities accompanying osteoarthritis. However, current practice does not allow the joints of the foot to be measured since the foot is treated as a single rigid segment. To develop a multi-segment kinematic model of the foot for use in a clinical motion analysis laboratory. Apply the model to a healthy population during normal walking and gait intentionally disrupted by a high arch orthotic.
The foot was defined as five rigid segments: hindfoot (calcaneus), midfoot (tarsus), medial forefoot (first metatarsal), lateral forefoot (fifth metatarsal) and the hallux (both phalanges). Each of these segments were tracked individually using custom-built marker triads attached to the skin. Thirty healthy subjects (eleven male, nineteen female; mean age 27.7 years, range 19–53) were examined using MA (eight Eagle camera, EvaRt system, Motion Analysis Corp., Santa Rosa, CA, USA) during normal walking and gait disrupted with a high arch orthotic taped to the plantar surface. All trials were performed barefoot. The special foot marker system was applied to the right foot with the remaining markers in the Helen Hayes configuration. Three motions are reported. The hallux-medial forefoot angulation (HA) is reported in the sagittal plane (plantar-dorsiflexion). The hindfoot-midfoot angulation (HFA) is also reported in the sagittal plane (plantar-dorsiflexion). The height-to-length ratio of the medial-longitudinal arch (MLA) is reported, normalised to zero in quiet standing. Paired t-tests compared the normal and disrupted gait conditions. All angles were compared at the instant of foot flat.
HA was not significantly changed between normal and disrupted conditions: from 8.5° ± 6.4° to 8.6° ± 7.4° (p=0.88). The HFA plantar-flexion significantly increased from 0.5 ° ± 3.3° (normal) to 2.9° ± 4.4° (disrupted; p< 0.01); mean difference = +2.5° (95% CI: 0.81 to 4.1°). The MLA was significantly increased (arch raised) from 0.004 ± 0.018 (normal) to 0.017 ± 0.021 (disrupted; p< 0.01); mean increase = +0.012 (95% CI: 0.00421 to 0.021).
A multi-segment kinematic model of the foot has been successfully implemented in an optical motion analysis laboratory. The model was sensitive to an intentional disruption of normal foot kinematics during walking in a healthy population.
To study the association between hip and ankle biomechanics during gait and moderate knee osteoarthritis (OA).
Gait analysis was performed on a group of forty-four patients clinically diagnosed with moderate knee OA, and on a group of sixty asymptomatic subjects. Three-dimensional net joint angles and net joint reaction moments at the hip, knee and ankle joints were calculated. Peak values were extracted from the gait waveform patterns and compared between the two subject groups with Student’s t-tests.
The peak hip extension moment, the peak hip adduction moment, the peak hip internal and external rotation moments, and the peak ankle dorsiflexion and plantarflexion moments were all reduced in the knee osteoarthritis population compared to the asymptomatic population.
Differences in knee joint loading patterns with moderate knee osteoarthritis have been previously reported, but these data suggest that changes in the mechanical environment of all lower extremity joints are associated with early stages of knee osteoarthritis. Other studies have associated reduced peak hip adduction moments with reduced likelihood of OA progression. These data provide a rationale for hip abductor muscle strengthening as a means to lower knee joint loading.
Elevated intracompartmental pressure (ICP) results in tissue damage due to impaired microcirculatory function. The nature of microcirculatory impairment in elevated ICP is not well understood. This study was designed to measure the effects of increased ICP on skeletal muscle microcirculation, inflammation and cell viability using intravital videomicroscopy.
Twenty adult male Wistar rats were randomised to four groups: the control group (control) had no intervention; while three experimental groups had elevated ICP maintained for fifteen (15m), 45 (45m), or ninety (90m) minutes. Compartment pressure was continuously monitored and controlled between 30¡V40mmHg in the posterior hindlimb using saline infusion into the anterior hindlimb. Mean arterial pressure was maintained between 80 and 120mmHg. Fasciotomy was then performed and the Extensor Digitorum Longus muscle studied using intravital videomicroscopy. Perfusion was measured by comparing the numbers of continuous, intermittent, and nonperfused capillaries. Inflammation was measured by counting the number of activated (rolling and adherent) leukocytes in post-capillary venules. Muscle cellular Injury was measured using fluorescent vital staining of injured cell nuclei.
Perfusion: The number of continuously perfused capillaries decreased from 77 ± 3/mm (control) to 46 ± 10/mm (15m),40±10/mm(45m)and27±8/mm(90m)(p< 0.05). Non-perfused capillaries increased from 13 ± 1 (control) to 16 ± 4 (15m), 30 ± 7 (45m), and 39 ± 5 (90m) (p< 0.05). Inflammation: Activated leukocytes increased from 3.6 ± 0.7/(100ƒÝ)2 (control) to 5.9 ± 1.3 (15m), 8.6 ± 1.8 (45m), and 10.9 ± 3.0/(100ƒÝ)2 (90m) (p< 0.01). Injury: The proportion of injured cells increased from 5 ± 2 % in the control group to 12 ± 3 (15m), 16 ± 7 (45m) and 20 ± 3 % (90m) (p< 0.05).
As little as fifteen minutes of 30mmHg ICP caused irreversible muscle damage and microvascular dysfunction. With increased duration, further decreases in capillary perfusion and increases in injury are noted. A severe inflammatory response accompanies elevated ICP. The role of inflammation in compartment syndrome is unknown, but may contribute to cell injury and reduced capillary perfusion.
To compare strength and recruitment of periarticular knee muscles in subjects with severe osteoarthritis (OA) one week before and one year after a total knee replacement (TKR).
Twenty-eight subjects, mean age = 64.5 years, with severe knee OA performed maximum voluntary isometric contractions for six exercises designed to test knee flexor and extensor and plantarflexor muscle strength. Torque and surface electromyograms (EMG) from the lateral and medial gastrocnemius, lateral and medial hamstring, vastus lateralis and medialis and rectus femoris muscles were recorded. Exercises included knee extension and flexion at mid range (45°) and closed-pack (15°) positions and plantarflexion with knee extended. Subjects completed WOMAC questionnaires to assess function. Custom software written in Matlab version 7.0.4 was used to calculate muscle torque and process EMG data. Paired Student t-tests (alpha = 0.05) were used to detect significant differences between pre-test and post-test data. Statistical analyses were performed in Minitab.
Post-TKR torque increases ranged from 1.6% to 19.7%, but only knee extension with the subject’s knee at 45° showed a statistically significant (p< 0.05) increase (74.3 ± 29.5 Nm to 86.1 ± 28.5 Nm). EMG amplitudes increased for the quadriceps and hamstring muscles (p< 0.05) post TKR, but the relative contributions of each muscle did not change, excepting rectus femoris. Within each exercise, some subjects increased their torque, but almost as many decreased their post-TKR torque. WOMAC scores for pain, stiffness, and function improved significantly (p< 0.05) by one year after TKR.
TKR surgery is becoming more common as a treatment for OA, but few studies have examined muscle strength before and after, which impacts patient function and the lifespan of the implant. By one year post-TKR subjects reported significant decreases in pain and stiffness, and significant improvements in function. This is consistent with the literature. Half of the subjects decreased in muscle strength to levels lower than pre-surgery. The results provide evidence that post-TKR management must address muscular strength deficits in addition to subjective assessments of improved symptoms to measure success.
The purpose of this study was to compare the post operative ROM of patients randomised between SRA and 28mm THA.
Restoration of normal ROM has been proposed as an advantage of hip resurfacing (SRA) over THA and is due to the use of larger diameter femoral heads. However, the head-neck diameter ratio, which is an important factor governing ROM, would in theory allow more ROM with THA (28mm head/14mm neck = ratio 2:1) versus SRA (approximate ratio 1.3–2.0:1).
Patients were randomised between SRA and THA. Osseous landmarks were identified with a marker pen. Both ASIS served as the reference line for the pelvis position. Digital photographs of hip motion were taken and a blinded rater (with respect to the side and type of surgery) performed range of motion testing on the operated and normal side. Pre-study validation of ROM measurement method with a software program revealed high intra and inter observer reliability.
Sixty SRA and sixty-two THA were evaluated at minimum follow-up of twelve months. Preoperative ROM and demographic data were similar for both groups. No significant differences (p> 0.05) were found in the total arc of motion (SRA=204.2°, THA=196.5°), arc of rotation (SRA=47.7°, THA=44.3°), flexion-extension arc (SRA=118.1, THA=120.1), abduction-adduction arc (SRA=43.1°, THA=42.9°).
In theory, ROM should have been greater in THA. Fear of instability may have limited ROM recovery potential in THA. Since pre operative soft tissue contracture is an important factor influencing post operative ROM, the complete capsular release performed during SRA may have been an advantage of this technique.
We aimed to establish if radiological parameters, dual energy x-ray absorbtiometry (DEXA) and quantitative CT (qCT) could predict the risk of sustaining a femoral neck fracture following hip resurfacing.
Twenty-one unilateral fresh frozen femurs were used. Each femur had a plain AP radiograph, DEXA scan and quantitative CT scan. Femurs were then prepared for a Birmingham Hip Resurfacing femoral component with the stem shaft angle equal to the native neck shaft angle. The femoral component was then cemented onto the prepared femoral head. No notching of the femoral neck occurred in any specimens. A repeat radiograph was performed to confirm the stem shaft angle. The femurs were then potted in a position of single leg stance and tested in the axial direction to failure using an Instron mechanical tester. The load to failure was then analysed with the radiological, DEXA and qCT parameters using multiple regression.
The strongest correlation with the load to failure values was the total mineral content of the femoral neck at the head/neck junction using qCT r= 0.74 (p< 0.001). This improved to r=0.76 (p< 0.001) when neck width was included in the analysis. The total bone mineral density measurement from the DEXA scan showed a correlation with the load to failure of r=0.69 (p< 0.001). Radiological parameters only moderately correlated with the load to failure values; neck width (r=0.55), head diameter (r= 0.49) and femoral off-set (r=0.3).
This study suggests that a patient’s risk of femoral neck fracture following hip resurfacing is most strongly correlated with total mineral content at the head/neck junction and bone mineral density. This biomechanical data suggests that the risk of post-operative femoral neck fracture may be most accurately identified with a pre-operative quantitative CT scan through the head/neck junction combined with the femoral neck width.
To assess the accuracy of plain digitised radiographic images for measurement of neck-shaft and stem-shaft angles in hip resurfacing arthroplasty.
Fifteen patients having undergone hip resurfacing arthroplasty with the Birmingham Hip Resurfacing (BHR) were selected at random. Digital radiographs were analyzed by three observers. Each observer measured the femoral neck-shaft angles (NSA) of the pre-operative and stem-shaft angles (SSA) of the postoperative radiographs on two separate occasions spanning one week. The effect of femur position on SSA measured by digital radiographs was also analyzed. A BHR prosthesis was cemented into a third generation Sawbone composite femur. Radiographs were taken with the synthetic specimen positioned in varying angles of both flexion and external rotation in increments of 10° ranging from 0° to 90°.
The mean intraobserver difference in measured angle was 3.13° (SD 2.37°, 95% CI +/−4.64°) for the NSA group and 1.49° (SD 2.28°, 95% CI +/−4.47°) for the SSA group. The intraclass correlation coefficient for the NSA group was 0.616 and for the SSA group was 0.855. Flexion of the synthetic femur of twenty degrees resulted in a five degree discrepancy in measured SSA and flexion of forty degrees resulted in a thirteen degree discrepancy. External rotation of the synthetic specimen of twenty and forty degrees resulted in a three and nine degree discrepancy in measured SSA, respectively.
Patient malposition during radiographic imaging can contribute to erroneous NSA and SSA results. Significant intra- and inter-observer variation was noted in the measurement of neck shaft angle however, variation was less marked for measurement of stem shaft angle.
Digital radiography has replaced traditional radiography in many hospitals yet little is known regarding the accuracy of this new technology in THA templating. Our study analyzed the reproducibility and reliability of computer templating in primary uncemented THA as compared to standard on-lay templating techniques with hardcopy radiographs from a digital source.
In December 2004 our hospital converted from standard hardcopy radiography to digital radiography. Patients undergoing THA had preoperative digital radiographs taken which included an AP pelvis with a 50mm magnification marker place in the groin, AP hip, and a cross-table lateral. Forty patients were selected that met our inclusion criteria to begin the templating process, including adequate placement of the magnification marker and optimal hip implant positioning on the postoperative films. Cases that did not have a marker, had significant deformity or mal-positioned implants were excluded. Hardcopies of digitised radiographs were printed and a traditional templating technique using 120% magnified on-lay transparent templates was performed (Capello, 1984). Digital templating was performed using OrthoView Software (Bono, 2004). Templating was conducted by two staff surgeons and one resident. Intra-observer and inter-observer effects were calculated using an Intraclass Correlation Coefficient (ICC).
Digital templating showed good inter-observer and intra-oberserver reliability with ICC values > 0.7. Using computer templating, the femoral stem was accurately predicted to within one size in 85% of the cases, and the acetabular cup was accurately predicted to within one size in 80% of the cases.Using on-lay templating, the femoral stem was accurately predicted to within one size in 85% of the cases, and the acetabular cup was accurately predicted to within one size in 60% of the cases.
There was a significant difference between the accuracy of acetabular cup templating between techniques, likely as a result of the ability of computer templating to adjust for magnification error. Computer templating was able to accurately predict postoperative leg-length discrepancy, abduction angle and horizontal offset. Overall, computer templating was found to be a reproducible and reliable technique for uncemented THA. Problems and lessons learned in the implementation of a digital templating system will be discussed.
The purpose of this study was to investigate the effect of knee flexion contracture on trunk kinematics.
Ten healthy old women, averaged sixty-two years, participated in this study. Subjects were tested at our laboratory with use of gait analysis system which consisted of eight retro-reflective markers (placed at bilateral acromion, anterior and posterior superior iliac spine, and iliaccrest), and five cameras. Unilateral (only right side) knee flexion contractures of zero, fifteen, and thirty degrees were simulated with a hard brace. All subjects performed walking trials at their preferred speed with or without simulation. First, level walking was measured without simulation, and then, with simulation at zero, fifteen and thirty degrees of flexion in order. Walking trials without brace was used as control. We evaluated walking velocity (m/s) and trunk kinematics (degrees). In the coronal plane, shoulder-pelvis bending angle was defined as the angle between shoulder girdle line and pelvic line. In the sagittal plane, anterior inclination of the trunk was defined by the slope linked right acromion and iliac crest, and anterior inclination of the pelvis was defined by the slope linked right superior anterior iliac spine and right superior posterior iliac spine. Shoulder-pelvis rotation angle was defined as the angle between shoulder girdle line and pelvic line in the axial plane. Maximum values were calculated.
Walking velocity was significantly decreased at thirty degrees contracture (1.19 at controls, 0.98 at thirty degrees contracture). In the coronal plane, trunk significantly tilted leftward rather (4.5) than rightward (1.8) at thirty degrees contracture. In the sagittal plane, trunk anterior inclination significantly increased at thirty degrees contracture (0.1 at controls, 3.1 at thirty degrees contracture). However, pelvic anterior inclination was similar. In the axial plane, trunk significantly rotated rightward (6.7) rather than leftward (4.3) at thirty degrees contracture.
Knee flexion contracture significantly influences physiological trunk kinematics in each plane. In particular, lateral bending to the contracture side was restricted, and this fact indicated that the lumbar spine may bend convexly to knee contracture side. These facts may result in Knee-Spine Syndrome.
Optimal soft tissue tension maximises function following total knee arthroplasty. Excessive tension may lead to stiffness and or pain, while inadequate tension can lead to instability. Composite component thickness is a prime determinant of this soft tissue tension. The variable component thickness provided by polyethylene inserts generally allows for 2–3mm incremental change. This study analyzed the effect of 1-mm incremental changes in polyethylene thickness on soft tissue tension. Our hypothesis was that soft tissue tension would be markedly affected by increases in insert thickness.
Computer assisted TKA was performed on eight cadaveric knee specimens (four pairs). The knees were passively moved through full flexion-extension range of motion, for each tibial construct thickness. Kinematics were recorded using the computer navigation software. Soft tissue tension was analyzed by measuring compartmental loads. A validated load cell instrumented tibial insert was used to measure medial and lateral compartmental loads independently. The effect of 1-mm increments in polyethylene thickness on compartmental loads was evaluated.
An increase in compartmental loads was measured with increasing insert thickness. Loading in contralateral compartments showed differing behaviour, reflecting varying tension in the medial and lateral sides. Many generated loads showed a reduction after reaching a maximal level with further increase in insert thickness (seven of eight specimens), indicative of tissue failure, although there were no overt indications of failure during the procedure. With a 1-mm increase in insert thickness, six of eight specimens showed an increase in peak loads greater than 100N at some point in the testing procedure, although not always with the same shim thickness.
Compartmental loads varied as a function of insert thickness. Most specimens showed signs of soft tissue “micro-failure”. The high sensitivity of compartmental loads to a 1-mm incremental increase is significant and has not been previously appreciated, especially intra-operatively. Currently available inserts with 2–3mm incremental sizes may make obtaining optimal soft tissue tension difficult. In addition to the current focus of obtaining accurate leg alignment, further computer-assisted techniques are required to address soft tissue tension.
Comparison of two cementing techniques: femoral component insertion into early-cure stage cement and insertion into late-cure stage cement in an in vivo model to identify if cement cure stage affects the strength of the bone cement interface.
Bilateral arthroplasties – using only the femoral component - were performed in vivo on paired porcine femora. The femora were harvested and cross-sectioned in preparation for strength testing. Performance was measured by peak load required to push the femoral prosthesis and surrounding cement mantle free of the cancellous bone.
The mean failure load for prostheses inserted into late cure stage cement was 908 N +/− SD 420, whereas the mean failure load for the conjugate early cure stage cement was 503 N +/− SD 342. A paired t-test indicated significantly higher load failure rates in the late cure stage cement versus the early cure stage samples (t=2.37, p< 0.049).
Femoral component insertion into late cure stage cement required statistically significant higher loads for push-out when compared to femoral component insertion into early cure stage cement.
Attempts have been made to develop standardise guidelines for knee implant wear testing of polyethylene (PE). The current ISO-14243-3 standard recommends the use “calf serum”, without giving ranges on the specific protein constituents and characteristics. In the present study, three types of frequently used calf sera with various protein constituents (albumin, globulins) were utilised. The effect of osmolality and hyaluronic acid (HA) was also assessed. An attempt was made to identify synovial fluid (SF) characteristics that may be responsible for the boundary lubrication in the joint with the goal to develop a more clinically relevant lubricant.
Twenty samples of SF were drawn from twenty patients and analyzed. Specific protein constituents and osmolality were then compared to three calf sera used for wear testing. Test One (six million cycles (Mc)): Bovine calf serum (BCS), newborn calf serum (NCS) and alpha-calf serum (ACS) were diluted with distilled water (DW). Test two (5.5Mc): ACS with an osmolality of 312 ± 1.00 mmol/kg (closest to clinical osmolality; diluted with phosphate buffered saline, PBS) and 145 ± 2.00 mmol/kg (diluted with DW) were consecutively tested. HA was added at a concentration of 1.5g/l. Modular total knee replacements of cruciate retaining design (GUR 1050, 10mm PE insert) were used.
ACS diluted with PBS appeared to be of closest specific protein constituents and osmolality when compared to SF. The wear rate for BCS was 21.81 ± 2.48 mg/Mc, 17.05 ± 3.25 mg/Mc for NCS, and 13.44 ± 0.79 mg/Mc for ACS (p < 0.016). Decreased osmolality amplified the PE wear by a factor of 2.3 (p = 0.020). Adding HA increased the PE wear by a factor of two (p = 0.002).
There was significant difference in PE wear rates between the three calf-sera. BCS and NBC did not have clinically relevant levels of specific protein constituents. This study strongly suggests that current standards for total knee wear testing should be revised to enable more controlled wear testing under more clinically relevant conditions. It is suggested to be of particular importance when new bearing materials, such as cross-linked PE’s, are evaluated and proposed for clinical application.
The purpose of this investigation was to determine the changes in frontal plane kinetics (loading) and neuromuscular responses pre and post unilateral total knee replacement surgery (TKR) during walking.
Thirty-four patients with severe knee osteoarthritis (within one week prior to TKR surgery) underwent a gait analysis. 3D kinematics, kinetics and electromyographic (EMG) recruitment patterns from seven lower limb muscles (vastus medialis and lateralis, medial and lateral hamstrings, medial and lateral gastrocnemius and rectus femoris) were recorded while walking at their self-selected walking speed. This was repeated one-year post-TKR surgery. EMG data were normalised to maximum voluntary isometric contractions and the knee adduction moment was normalised to body mass. All waveforms were normalised in time to 100% of the gait cycle. Principal component analysis was applied to the pre-and post-TKR waveforms. T-tests and ANOVA models tested pre-post TKR differences and differences between muscles.
At pre-TKR, the average age of the subjects was 66 ± 6.6 years and there were no statistically significant differences between pre and post TKR measures of mass (90Kg). The walking velocity significantly (p< 0.05) increased from the pre-TKR (.9 ±.23 m/s) to the post-TRK (1.07 ±.21 m/s). There were statistically significantly (p< 0.05) magnitude and shape differences between the pre-and-post-TKR waveforms for the knee adduction moment and the EMG waveforms. In general there were reduced adduction moments and EMG amplitudes for quadriceps and hamstrings post-TKR.
The results show improved function with the increased walking velocity, but more important are the differences with respect to joint loading and muscle function. The decreased knee adduction moment post-TKR reflects reduced loading on the medial compartment of the prosthesis. The alterations in the quadriceps and hamstrings illustrate that post-TKR the muscles no longer co-activate at high percentage of their maximum during the majority of the gait cycle as was shown in the pre-TKR waveforms. Finally the high lateral hamstring activity found pre-operatively was reduced resulting in a more balanced activation between the medial and lateral sites post operatively. These post-TKR changes have implications for improved joint loading, reduced risk of muscle fatigue and decreased metabolic costs associated with walking.
Stress shielding (i.e. reduction in bone strains) in the distal ulna is commonly noted following ulnar head replacement arthroplasty. Optimal design parameters for distal ulnar implants, including the length of the stem, are currently unknown. The purpose of this study was to investigate the effect of stem length on bone strains along the length of the ulna.
Strain gauges were applied to each of eight cadaveric ulnae to measure bending loads at six locations along each ulna’s length (approximately 1.5, 2.5, 4.0, 6.0, 8.0, and 13.0cm from the ulnar head). The proximal portion of each bone was secured in a custom-designed jig. A materials testing machine applied loads (5–30N) to the ulnar head while native strains were recorded. The ulnar head was removed and the loading procedure repeated for cemented stainless steel stems 3 and 7cm in length, according to a previously reported technique (Austman et al, CORS 2006). Other stem lengths between 3 and 7cm were tested in 0.5cm intervals with a 20N load applied only. Data were analyzed using a two-way repeated measures ANOVA (á=0.05).
In general, distal bone strains increased as stem length decreased (e.g. average microstrains at the second distal-most gauges: 138±13 (7cm), 147±15 (6cm), 159±21 (5cm), 186±40 (4cm), 235±43 (3cm)). The native strains were different from all stem lengths for the four distal-most gauges (p< 0.05). No differences were found between any stem length and the native bone at the two proximal-most gauges. The 3cm stem replicated the native strains more closely than the 7cm, over all applied loads (e.g. average microstrains at the third gauge level for a 25N load: 357±59 (native), 396±74 (3cm), 257±34 (7cm)).
No stem length tested matched the native strains at all gauge locations. The 3cm stem results were closer to the native strains than the 7cm stem for all loads at gauges overtop of the stem. Overall, the 3cm stem produced the highest strains, and thus would likely result in less distal ulnar bone resorption after implantation. These results suggest that shorter (approximately 3cm) stems should be considered for distal ulnar implants to potentially reduce stress shielding, although this must be balanced by adequate stem length for fixation.
The purpose of the study was to determine the effectiveness of rhBMP-2 when applied to an absorbable collagen sponge for interbody fusion with allograft spacers.
Seventy-seven consecutive patients requiring inter-body fusion with one hundred and eighteen levels were included in the study. In thirty-six patients cervical or lumbar interbody fusions were performed using allograft and rhBMP-2. In the remaing allograft was used with demineralised bone matrix. In patients undergoing anterior cervical decompression and fusion (ALIF) machined allograft spacers were supplemented with anterior locking plates. In those scheduled for anterior lumbar inter-body fusion (ALIF) or transforaminal lumbar interbody fusion (TLIF), machined allograft spacers were supplemented with posterior pedicle screw constructs. There were no stand alone ALIF procedures. All patients undergoing surgery were assessed preoperatively and at two weeks, six weeks, three, six, twelve, twenty-four months following surgery.Their Oswestry disability index (ODI) questionaires, Visual analogue scale (VAS) scores and a pain diagram were recorded. Radiographic measurements were made on the electronic public access computer system (EPACS).
All patients with allograft plus rhBMP-2 showed radiographic evidence of fusion by six months following surgery. The allograft with demineralised bone matrix group took considerably longer to achieve the same radiographic end plate appearance. Subsidence was obvious on radiographs in greater than 50% of cases with allograft and rhBMP-2 at three months. It was noted to occur between six weeks and three months and there was no significant subsidence after six months. This was statistically significant with a p< 0.0001 (fisher exact test). The average subsidence for the entire rhBMP-2 group at twelve months was 16.5%(SE 2.5% and range 0–58%) and for the allograft and bone matrix group was 4.6%(SE.74% range 0–15%)with a p< 0.0001 (independant t test).
Although high rates of fusion can be accomplished with allograft and rhBMP-2 (100%), significant subsidence occurs in greater than 50% of lumbar spine cases and 30% of cervical spine cases. This is possibly a result of early bone turnover with loss of structural support of the allograft spacer and end plate resorption.
For hip resurfacing arthroplasty, precise planning and implantation of the components is necessary for long-term success. Earlier studies have shown that a computer-assisted technique can achieve higher accuracy than conventional technique. However, many of the proposed computer systems add additional complexity, time and cost to the surgery. This study investigated the use of rapid prototyping as an accurate, fast and cost-effective solution for computer-aided hip resurfacing.
From a CT scan of each patient, a 3-dimensional computer model of the proximal femur was produced and the drilling trajectory for the central pin of the stem was planned. To transfer this plan to the patient, surface-matched plastic drilling templates were created using a rapid prototyping machine. Depending on the surgical approach, these templates contained a mirror-image of parts of the anterior or posterior femoral head and neck. These mirror-image templates helped to exactly position the drilling guide on the bone during surgery, which ensures a precise transformation of the preoperative plan into the surgical field. To test the accuracy and reproducibility of this system, we created plastic models of three cadaver femurs using the rapid prototyping machine. For each of these femurs one anterior and one posterior drilling template were generated. Each template was applied three times to the femur model and the direction of the drilling target was recorded and axis deviations measured.
The average deviation between the planned and the template-guided drill direction was 1.3° for the anterior approach and 1.2° for the posterior approach. The reproducibility for the drilling axis was measured for the anterior approach as 0.4° and posterior 0.3°.
In comparison to previous published results for computer-assisted hip resurfacing, our results show similar or better accuracy. Further in-vitro and in-vivo experiments will be performed to obtain statistically significant accuracy measurements and intraoperative feasibility tests. Our early results show great potential for this technique for accurate and in-expensive guidance for hip resurfacing.
To evaluate the clinical accuracy of computer-assisted fluoroscopy for the placement of percutaneous lumbosacral (LS) pedicle screws.
A prospective computed tomographic (CT) analysis was performed in forty consecutive patients. Three independent observers were utilised. Postoperative CT scans of one hundred and fifty-nine titanium pedicle screws (n = 6(L3); thirty-eight(L4); sixty-five(l5) and fifty(S1)) were reviewed. All screws were percutaneously placed using the two-dimensional FluoroNavTM system. The relative position of the screw to the pedicle was graded as follows: I-completely in; II – < 2mm breach; III - = 2–4mm breach; IV – > 4mm breach. The direction of the breach was further classified as well as its trajectory.
Correlation between observers was near perfect. The three observers rated 74.2%, 78.6%, and 78.0% of screws were completely contained within the pedicle. The data from the observer with the most significant pedicle breaches is as follows: thirty-five (22%) pedicle breaches (grade II -n=30; III - n=4; IV - n=1/n= 11 medial; n=19 lateral; 5 superior). Only one clinically significant breach occurred medially (grade III) at L5. This required screw revision (performed with a minimal access technique) with complete resolution of acute post-op L5 radiculopathy.
The in-vivo percutaneous pedicle breach rate in this study was higher than that reported for similar open navigational techniques. The majority (85.7%) of breaches were minor (< 2mm) and over half (54.3%) were lateral with no potential for clinical squealae. This high lateral breach rate is due to a modified lateral starting point required for the percutaneous technique. However, there is concern that this technique resulted in one clinically significant medial breach and highlights the increased risk associated with percutatneous pedicle screw placement. The findings of this study suggest that improved screw placement accuracy for minimal access instrumented fusions is required.
Accurate implant alignment with the flexion-extension axis of the elbow is likely critical for optimal function and durability following elbow replacement arthroplasty. Implant alignment can be optimised by imaging the contralateral normal elbow prior to surgery and transferring this information to the diseased elbow in the operating room through registration. Successful registration is dependent on the presence of unique anatomical landmarks. Bone loss can create a challenge for registration as key anatomical landmarks are absent, limiting the number of sampling areas. This study investigated the effect of intraoperative sampling area on registration accuracy. We hypothesised that a low registration error can be achieved by acquiring surface data from areas unlikely compromised due to injury and readily available to the surgeon during typical surgical exposures.
CT images of twenty cadaveric distal humeri were acquired. Surface data was acquired from nineteen anatomical landmarks of the distal humerus using a hand-held laser scanner (FastSCANTM, Polhemus). Registration to the CT image was performed for thirty-nine landmark combinations. Only six combinations are discussed for succinctness.
Combining data from the anterior articular surface and humeral shaft, the lowest registration error was achieved in translation (0.8±0.3 mm) and rotation (0.3±0.2°). However, using data from the posterior shaft and proximal medial supracondylar column, a registration error of 1.1±0.2 mm and 0.4±0.2° was achieved.
Based on the results of this study, a low registration error can be achieved by acquiring data from two areas that are located proximal to the articular surface (the proximal medial supracondylar column and posterior humeral shaft), readily available surgically, and unlikely compromised due to distal humeral fractures, non-unions or bone loss due to severe erosive arthritis. Registration error was similar to the reported resolution of the laser scanner. Overall, this study demonstrates the promise for a successful registration of the contralateral normal elbow to physical surface data of the diseased or injured elbow using only a small portion of undamaged bone structure.
The purpose of this study was to assess the effect of total knee arthroplasty (TKA) on the gait symmetry of patients suffering from osteoarthritis. TKA is an effective method of relieving pain and restoring function but many established outcome measures are subjective and based on patient self-report. This study used clinical gait analysis with the Walkabout Portable Gait MonitorTM (WPGM) to describe pre and post-operative function in a more objective manner.
The WPGM is a tri-axial arrangement of accelerometers that a subject wears around the waist, approximating the position of the center of mass (COM). Twenty-one TKA patients underwent a standardised WPGM assessment (a walk at a self-selected speed along a 50m hospital corridor) and completed the WOMAC and SF-36 subjective questionnaires preoperatively and three years after surgery. Data was recorded at 200 Hz for approximately twenty to twenty-five seconds. Automated Fast Fourier transformations (FFT) of the displacement data in three axes yields data on the ‘repeating irregularities’ that result from musculoskeletal injury or compensatory mechanisms and provides three clinically significant ratios Surge (asymmetry in the gait cycle in the forward direction), Lurch (side to side displacements that becomes asymmetrical with unilateral pathology) and Functional Leg Length Difference (FLLD) (asymmetry in vertical displacement during the gait cycle).
Paired t-tests show that mean Surge (p< 0.006), FLLD (p< 0.0001) and Lurch (p< 0.008) were reduced following TKA for treatment of osteoarthritis. This is evidence that the asymmetry of gait was successfully reduced and subsequently overall gait was improved following surgical intervention. Patients’ WOMAC and SF-36 questionnaires showed significant improvements in patient pain, stiffness and physical function post-operatively (p’s< 0.01).
Advantages of using the WPGM in addition to standard patient self-report questionnaires include the ease of testing, quick analysis and ability to detect musculo-skeletal health changes that might otherwise be masked by extraneous variables. A small subset of patients did not realise significant improvement in gait parameters post-operatively. On closer inspection, these patients had near normal gait patterns pre-operatively. This suggests the WPGM has great potential for objectively prioritizing patients waiting for TKA and assessing post-operative outcome.
To determine the pattern of brace wear compliance over time in both day and night time wear by using objective force measurements within the brace.
Twenty subjects who were diagnosed of AIS, age between nine and fifteen years, and new to brace treatment were recruited in this study. To use the data for analysis, only subjects who used the brace for five hours continuously either in daytime or nighttime were considered. For daytime wear, the selected five hour intervals had to begin with an initial spike in force after a period of non-activity as recorded by the transducer, which would indicate that they had just put on the brace. At night, the measurements began at one am and ended at six am.
Among the twenty subjects, only nine subjects’ data were used for daytime and eleven subjects’ data were used in nighttime. The average wear period was 11.4 ± 4.3 days for the day group, 11.6 ± 3.9 days for the night group. There was a statistically significant decrease in force within the first five hours of consecutive brace wear during daytime hours. The decrease was from 1.4 ± 0.6 (140% of prescribed force) in the first hour to 1.0 ± 0.6 in the fifth hour, a difference of 0.4, which is a 29% drop from the initial force. Most of the drop in force happened between hour one and hour two, as the difference in those two hours is 0.2 ± 0.1 (p = 0.001); between hours two and five the difference did not reach statistical significance. The observed difference between hours one and five for the night group was 0.2 ± 0.2, p = 0.06, which did not reach significance as well. Daytime forces in a Boston Brace tend to decrease over a period of time, but the nighttime forces seem to be maintained at the same level. These results show that daily adjustment of the brace tightness may be required to maintain the tightness level and the efficiency of brace treatment.
The purpose of the study was to examine the effects of vascular-targeted photodynamic therapy (PDT) using benzoporhyrin derivative (BPD) on growth plates in spine and long bones. Specifically we wish to determine whether the ipsilateral up-regulation of VEGF in the thoracic and/or lumbar spine following treatment with leads to onset of scoliosis morphologically similar to idiopathic adolescent scoliosis. And secondly confirm growth plate closure in long bones following BPD-PDT resulting in leg length discrepancy.
A 0.2 mm fiber was placed through an 18g needle onto one side of the distal femoral epiphysis (n=24) or lower thoracic/upper lumbar vertebral bodies of four-week old mice (n=18). Mice are genetically modified to emit bioluminescence upon activation of the vascular endothelial growth factor gene (VEGF). Accurate placement was confirmed using fluoroscopy. BPD (2 mg/Kg, i.v.) was administered systemically and the growth plates were stimulated with 690nm laser light five minutes later. Range of light dose regimens were tested. Animals were followed for a total of seven-twelve weeks post treatment. Faxitron imaging and bioluminescent imaging were obtained to determine leg length or curve progression and VEGF activity. Histology and immunohistochemistry including H& E, HIF-1á, CD31 and VEGF immunohistochemistry was performed.
PDT was able to up-regulate VEGF for up to four weeks following treatment following a percutaneous treatment using a 0.2mm treatment fiber both in the femur and vertebrae. Femoral shortening occurred with histological evidence of bone formation across the growth plate. We were able to identify using faxitron abnormal curvature in a number of the animals that received 5J, 10 mW regimen.
This study confirms that that the epiphyses of vertebrae and long bones are similarly susceptible to the effects of a hypoxic insult resulting in VEGF up-regulation. We are proposing that this stress response can lead to premature closure of epiphyseal growth plates of long bones resulting in limb growth arrest or asymmetric growth of vertebrae and the development of scoliosis in an animal model.
Linear spinal cord distraction, in animal models, leads to elevated intra-compartmental spinal cord pressure. We developed an in vitro model of distraction, with increasing tensile force, to demonstrate the relationship between the degree of spinal curvature and the proportional elevation of intra-compartmental pressure.
Six Porcine spinal sections, two cervical, two thoracic, and two lumbar were harvested from 30kg pigs. These cord sections were individually stretched in a saline solution with increasing tensile force applied. Cord interstitial pressure (CIP) was monitored with an arterial line pressure monitor. The sections were each tested six times fresh, and then thawed and tested an additional six times. An additional ten freshly thawed cords were tested in linear distraction and over forty-five degree and ninety degree curved surfaces with CIP monitoring.
Increased tension, by adding increasing weights of distraction, lead to a proportionally elevated CIP in the linear model (R=0.986). We achieved a 99% confidence interval via paired T testing to demonstrate that there was no significant difference between fresh specimens and recently thawed cords. As the degree of spinal curvature increased from a linear model, to a forty-five and ninety degree (cobb) curve, there were significant increases in CIP at the same distraction force. The more significant the curve, the greater the CIP for each increment in distraction force; ninety degree curves produced a 2.3x higher pressure than linear distraction.
High cord interstitial pressure (CIP) can be achieved through spinal cord distraction (> 140mm Hg). This CIP is no only directly proportional to tension, but also proportionally magnified by the degree of spinal curvature. It is not affected by freezing/thawing. This may suggest that spinal cord compartment syndrome is a potential mechanism for spinal cord distraction injury, and these distraction pressures are potentially magnified in the setting of scoliosis.
Brace correction based upon mechanical action requires appropriate interface pressure between the body and the brace.
A smart orthotic was developed to record how much time (quantity) a brace was used, how well (quality) it was used and maintain the interface pressure to the prescribed level. Six subjects were recruited and they all used Boston style braces. Each subject used the system for two weeks without the force maintenance system activated to serve as the control period, and the remaining two weeks with the force maintenance system activated. During the automatic feedback mode, the pressure maintenance system was activated only during the daytime (8:00–22:00hrs) to avoid disturbing the patients during sleep. The subject could either return the system to us after one month or continue to use the system until the next clinic.
The time that the pressure level was in the target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. The average brace wear time for the study period was 72 +/− 15% (12.6hr/day) of the prescribed time (17.5 +/− 3.8 hours). The curve severity of all subjects on the following clinical visit was the same (within measurement error) as the first visit (32 +/− 5 vs 31 +/− 5 degrees). Compliance was not affected when wearing the monitor.
The smart orthotic was able to improve the efficiency of a conventional brace by maintaining the prescribed interface pressure automatically. This proposed work helps brace candidates wear their braces more effectively and gets the most benefit from the brace treatment. As a result, all participated subjects maintained their Cobb angle within ± two degrees during the study period.
Rodents are often used as preclinical models for investigating the biomechanical consequences of spinal pathologies and interventions. Growth plates are present within rat vertebrae throughout life and may alter the vertebral biomechanics. This study investigates the biomechanical response of rat-tail vertebrae to axial compressive loading using μCT imaging and image registration to spatially resolve strain fields.
The sixth caudal vertebrae of eight immunocompromised (rnu/rnu) rats were μCT scanned (17.5 ×17.5×17.5μm/pixel) in both loaded (27N-32N axial compression) and unloaded configurations. Image registration was used to calculate strain and displacement fields in the bone due to the applied load by finding a spatial mapping between the two scans. Strain was resolved to varying spatial resolutions; high strain gradient regions, such as the growth plates, were analyzed to higher spatial resolutions.
Axial strains calculated by image registration ranged from 2% in tension to 16% in compression with an average axial strain of 1.6% in compression. In seven rats the majority of the strain measured within the vertebrae was concentrated in the growth plate. Very soft growth plates in three specimens resulted in maximum axial strains from 10–16% in compression. The remaining four rats with strain concentrations in the growth plate had maximum axial strains ranging from 2.2%–3.2%. Centrally located strain concentrations of lower magnitudes and more limited spatial extent were observed in the trabecular bone.
The majority of the strain within the rat vertebrae was absorbed by the growth plates. The amount of strain within the growth plate is important to consider when interpreting biomechanical data on rat vertebrae. Load application to rodent vertebrae will first compress the growth plate and only following compression of this structure cause significant development of displacement and strains within the trabecular and cortical bone. This insight into the biomechanical response of rat vertebrae is apparent through the application of image registration to analyse vertebral body behaviour; such information would not be evident in analysing preclinical whole vertebral body response using finite element modeling or experimental testing protocols.
Bone is the preferred site of metastases in women with breast cancer, which can cause skeletal-related events (SRE¡¦s) such as pathologic fractures. Bisphosphonates are the current standard of care for treatment of meta-static bone disease by preventing further bone destruction. Photodynamic therapy (PDT) has been applied successfully as a non-radiative treatment for malignancies. In PDT, light is delivered to a tumour after the administration of a photosensitiser. Earlier pre-clinical studies in a metastatic rat model have shown that PDT reduced the tumour burden in the vertebrae. The goal of this investigation was to study the effect of PDT on bisphosphonate pre-treated cancer in-vitro.
Human breast cancer cells, MT-1, were cultured until confluent. The following groups were formed: no treatment; incubation with zoledronic acid (24h; 10 ƒÝmol) only; PDT treatment only and incubation with zoledronic acid and PDT treatment. Prior to light application 1 microg/ml of the photosensitiser BPD-MA was added. PDT was performed with a light dose of 1J and 10 J. The cells were stained with a live/dead stain and analyzed by fluorescence microscope and flowcytometry.
Incubation of the MT-1 carcinoma cells with bisphosphonate zoledronic acid resulted in a significantly higher number of dying cells following PDT treatment when compared cells that were not treated by zoledronic acid (p< 0.05). When comparing cell groups that did not undergo PDT treatment the incubation with zoledronic acid alone did not have a statistically significant effect on cell survival twenty-four hours following zoledronic acid administration.
In-vitro, breast cancer cells appear more susceptible to PDT after they have been incubated with the zoledronic acid. Zoledronic acid, a potent bisphosphonate, inhibits farsenylpyrophosphate (FPP) which is involved in farsenylation of cell membrane proteins. The inhibition of FPP may cause a reduced effect of PDT on cell rescue. The treatment with bisphosphonates seems to have a synergistic effect with PDT treatment. As such, light dosimetry in PDT treatment may need to take into account potential therapeutic interactions between PDT and current medical therapies in the treatment of skeletal metastatic burden.
Versican is a large extracellular proteoglycan that is expressed in a variety of tissues and primary malignancies including infiltrating breast carcinoma. It also appears that versican can inhibit intercellular adhesion of normal as well as malignant cells. With the observation of selectin-like properties of versican G3 the investigators hypothesise that versican G3 influences not only local tumour invasiveness but also systemic metastases including the spread to bony sites. The present study aimed to test the hypothesis of versican G3 associated metastatic invasiveness in a murine osteolytic metastatic model of human breast carcinoma.
Human carcinoma cells (MT-1), transfected with the either a versican-G3-construct (n=7) or a vector-control (n=8) gene, were injected intracardically female athymic rats. The rats were examined clinically at serial time-points following injection and animal weight recorded. Animals were euthanised three weeks after tumour cell injection. On digital lateral radiographs of the scapula osteolytic areas were measured. Additionally, histomorphometry was performed on sections stained with human EGFr antibody to evaluate tumour burden within rodent vertebrae. Statistical analyses were performed using one way ANOVA.
All rats demonstrated weight loss approximately three weeks following tumour cell injection. However, the extent of weight loss observed over time was greater for the versicanG3 group (p< 0.05). Osteolytic metastases were observed using fine detail radiography at the day of euthanasia. Osteolytic burden was greater (p < 0.002) in the G3 transfected group (34.7 %; lytic area scapula) when compared to vector-control animals (8 %).
Versican G3 domain appears to influence the development of metastases to bone and soft tissue. The propensity of versican G3 to influence tumour invasion to bone and the mechanisms of versican G3 mediated osteolysis warrants ongoing study. With the known interactions between versican G3 and beta1 integrin in other cancer cell types and the increasing knowledge regarding several beta3 integrin-expressing cell populations, including osteoclasts in breast cancer tumour progression, the potential interaction between versican G3 and integrin receptors in bone may influence tumour mediating chemotactic and haptotactic migration towards bone factors.
Although the etiology of low back pain is unclear, it is believed that intervertebral disc (IVD) degeneration plays a major role. In the present study, we sought to determine if bovine IVD cells maintain their phenotype in a mouse subcutaneous injection model, while embedded or not in biocompatible matrices.
Nucleus pulposus (NP) cells were isolated from adult bovine tails. Ten million cells were resuspended either in 500 ƒÝl of DMEM or in a negatively (alginate) or positively (chitosan) charged matrix. The mixtures were then injected subcutaneously in Balc/c nude mice. After two weeks, the mice were sacrificed and the implants harvested. The implants were examined histologically with a hematoxylin and eosin stain. The implant size was measured and the cells were counted. Proteoglycan was assessed by the GAG assay. The expression of type I and II collagens, aggrecan, and CD24 genes was analyzed by reverse transcription ¡V polymerase chain reaction (RT-PCR).
Histologic evaluation confirms the presence of cells in all NP implants. The presence of alginate increased the implant size, the number of cells in the implants, and to a lesser extent, the proteoglycan content, compared to implants formed with cells injected alone. However, chitosan had no effect on the implant size, the number of cells and the aggrecan content. NP implants expressed the same pattern of genes as the native NP tissue (i.e. type I and II collagens, aggrecan, and CD24). The presence of alginate did not affect this expression pattern whereas chitosan decreased slightly their expression.
After injection in mice, bovine NP cells appeared to retain their native phenotype. The RT-PCR analysis revealed that NP cells expressed aggrecan, type I and type II collagens as well as CD24, a specific marker for the NP phenotype. Also, NP cells can be embedded in matrices to produce NP-like features in vivo. In conclusion, we have developed a simple mouse subcutaneous injection model that recreates the features of the native IVD and avoids the need to use a disc degeneration model.
To compare strains measured in a whole rat-tail vertebra by image registration (IM) with those predicted by solid finite element analysis (FEA). Quantification of bone strain allows better understand fracture risk, bone healing and turnover.
The sixth caudal vertebra of an rnu/rnu rat was μCT scanned (17.5×17.5×17.5μm/voxel) while loaded (27N axial compression) and unloaded. IM was used to calculate strain and displacement fields in the bone due to the applied load by finding a spatial mapping between the two scans. Strain was resolved to varying spatial resolution; high strain gradient regions (ie growth plates) were analyzed to higher spatial resolutions. A FE model was created of the unloaded vertebra, consisting of tetrahedral elements with transversely isotropic material properties. Elements were assigned elastic moduli based upon μCT image intensities. Growth plate moduli ranged from 0–150kPa and the bone moduli ranged from 0.2–15000MPa. Vertebral geometry was created through segmentation of μCT images. Displacement boundary conditions were obtained by matching cranial and caudal surfaces in the unloaded and loaded scans. The displacement fields of the two methods were compared by using the fields calculated to deform the unloaded scan to match the loaded scan. The strains were compared by plotting FEA measured axial strain against IM calculated axial strain.
The displacement fields calculated by both methods were able to spatially align the unloaded scan to the loaded scan (Mean Voxel Intensity Difference: FEA=441HU, IM=328HU, Unregistered=969HU). IM and FEA show very limited agreement in axial strain measurement (R2=0.388, Slope=0.75, X-Intercept=0.0037) although both calculated high axial strains in the growth plates and low axial strains in the trabecular and cortical bone. Good agreement was found in the mean axial strain measured by both methods (IM= −0.044, FEA=−0.037). IM was better able to deal with difficulties in quantifying bone strain due to the growth plate than FEA.
IM presents advantages over FEA in measuring strain in complex whole bone trabecular structures, however has lower spatial resolution than is possible with FEA.
Despite a relentless search for adequate and effective treatment, low back pain is one of the most prevalent and costly illness in today’s society. While disc degeneration has been implicated as a major etiologic component of low back pain, there has been relatively little study in developing an objective, accurate, non-invasive diagnostic tool in the detection and quantification of matrix changes in early disc degeneration. The aim of the present study was to establish the correlations between magnetic resonance (MR) parameters and the biochemical and mechanical properties of the nucleus pulposus (NP) undergoing targeted trypsin digestion and axial compression.
Three-disc segments from bovine tails were either unloaded or loaded (cyclic compression: 50N-300N-50N at 1 Hz for 16h) to evaluate the effect of compression loading and the interactive effects of trypsin treatment and mechanical loading. The MR examinations were carried out in a 1.5-Tesla whole-body Siemens Avanto System (Siemens AG, Germany). The frozen NP and annulus fibrosus (AF) tissue sections reserved for mechanical analysis were tested under confined compression; swelling pressure was calculated based on the increase in measured force throughout the initial dwell period. Total water, proteoglycan, collagen, and denatured collagen contents were also measured.
Results showed that loading had a significant effect on the MR properties (T1, T2, T1ñ, MTR, ADC) of both disc tissues. Loading had a greater effect on the MR parameters and biochemical composition of the NP than trypsin. In contrast, trypsin had a larger effect on the mechanical properties. Results also indicated that localised trypsin injection predominantly affected the NP. T1ñ was sensitive to loading and correlated with the water content of the NP and AF but not with their proteoglycan content.
Results support the concept that physiologic loading is an important confounder and that T1ñ is an essential parameter in efforts to develop quantitative MRI as a non-invasive diagnostic tool to detect and quantify matrix and material changes in early disc degeneration. Further studies are required to determine the potential of the T1ñ technique to be used as a non-invasive diagnostic tool of the biochemical and mechanical changes occurring in disc degeneration.
The purpose of this historical prospective study was to compare the pre and post-operative Quality of Life (QOL) outcomes twelve months post-operatively in patients with partial thickness rotator cuff tears.
Data of ninety-three consecutive patients diagnosed with Partial Thickness Tear (PTT) who had undergone decompression, acromioplasty, or repair were used to compare the outcome between patients with Articular Tears (AT) and Bursal Tears (BT). The QOL outcome measures included one disease specific outcome measure, the Western Ontario Rotator Cuff Index (WORC) and two shoulder specific measures, the American Shoulder & Elbow Surgeons standardised shoulder assessment form (ASES) and the Constant-Murley score. A statistical paired t-test (pre vs. twelve months) and an independent t-test analysis (Articular vs. Bursal) were conducted to examine the impact of the tear site.
Forty-four Articular and forty-nine Bursal tears (forty-eight females and forty-five males) were included in the analysis. The mean age was 55.5 (SD: 13) and 53.3 (SD: 12) for the AT and BT groups respectively. There was no statistically significant difference between the two groups in pre-operative QOL outcome scores. Both groups showed significant improvement in the above outcomes (p< 0.0001) one year following surgery. However, the AT group was significantly less improved than the BT group in the post-op ASES scores (p=0.04), Constant-Murley scores (p=0.006) and WORC (p=0.01).
The intent of this study was to compare the pre and post operative scores and rate of improvement in two groups of patients suffering from rotator cuff pathology at different sites. The results indicate that the quality of life improves significantly regardless of the tear site. The pattern of recovery however is different indicating that patients with Bursal tears show a higher degree of improvement in their functional measures. The findings suggest that two types of tears are different in their etiology and pathomechanics.
The purpose of this prospective randomised clinical trial is to examine the effect of acromioplasty on the outcome of arthroscopic rotator cuff repair.
Patients included individuals that were referred for assessment after six months of failed conservative management. Following informed consent patients were randomly assigned to receive arthroscopic rotator cuff repair with or without acromioplasty. The surgeon was not blinded to the type of procedure; however, the researcher who performed the follow-up evaluations and the patient was blinded to the surgical protocol. Subacromial decompression (acromioplasty) was performed with release of the coracoacromial ligament off the anterior undersurface of the acromion. The procedure for arthroscopic cuff repair without acromioplasty followed the protocol of arthroscopic cuff repair with acromioplasty, without division of the coracoacromial ligament or resection of the acromion. Both groups experienced the same post-operative rehabilitation protocol. Wound healing and active and passive range of motion were assessed and recorded at six to eight weeks post-operatively. Subsequent post-operative visits occurred at three, six, twelve, eighteen and twenty-four months and included documentation of patient range of motion, patient derived WORC scores (1) and complete ASES scores.
Preliminary results suggest, based on a one-tailed t-test, patients that receive a rotator cuff repair with acromioplasty demonstrate a statistically significant improvement (< 0.05) in Quality of Life, based on WORC and ASES scores, compared to the non-acromioplasty group. To date, three patients in the non-acromioplasty group required a revision surgery; two of these patients had a Type III acromion.
Arthroscopic rotator cuff repair with arthroscopic acromioplasty in the treatment of full thickness rotator cuff tears is recommended for patients with a Type III acromion.
The purpose of this study was two-fold: 1) to examine perioperative prospective changes in pain, disability and psychosocial variables in ACL reconstructed recreational athletes over the pre-op to eight week post-op period. 2) to see what variables will predict greatest disability at eight weeks post-op.
All participants were recreational athletes at the time of their injuries who had patella-autograft procedure at the the Queen Elizabeth II Health Sciences Centre. Fifty-four patients (twenty-nine males; mean age = 25.4 years, SD = 8.08). Mean education was fourteen years (SD = 2.08), 32%(17) were married, 67%(36) single, and 1% was divorced. 94%(51) of the sample was Caucasian, 3%(2) Black, and 1% Asian. One quarter reported their ACL injury was due to sport-based contact, with non-contact sporting activity reported at 76%(41). All participants completed measures of pain, depression, pain catastrophizing, state anxiety pre-op, on days one and two following surgery and again at eight weeks post-op. Disability was assessed pre-op and eight weeks post-op.
Pain was varied across comparisons with preoperative pain increased twenty-four and forty-eight-hour post-op. Pain at forty-eight-hours postoperative was significantly higher than pain reported at eight-weeks post-op. Catastrophizing did not differ from the pre-op to twenty-four-hour post-op but did drop from twenty-four to forty-eight-hours and forty-eight-hours to eight-weeks post-op. Pre-op depression increased twenty-four-hour post-op, but not from twenty-four to forty-eight-hours and declined at eight-weeks. Anxiety increase pre-op to twenty-four-hours but not from twenty-four to forty-eight-hours but did drop from forty-eight-hours to eight-weeks.Disability did not change over time. Regression showed age or gender did not predict disability but forty-eight hour pain and catastrophizing did.
These data indicate that pain and psychological variables change over time of ACL recovery. Results suggest that pain and distress peek during acute post-op period. As well, post-op catastrophizing predicts disability at eight weeks post-op which may indicate that catastrophizing may be related to behaviours related to slower recovery following ACL reconstructive surgery.
The purpose of this study was to review the results of biceps tenodesis and biceps reinsertion in the treatment of type II SLAP lesions.
We conducted a retrospective cohort study of a continuous series of patients. Only isolated type II SLAP lesions were included: twenty-five cases from January 2000 to April 2004. Exclusion criteria included associated instability, rotator cuff rupture and previous shoulder surgery. Ten patients (ten men) with an average age of thirty-seven years (range, 19–57) had a reinsertion of the long head of the biceps tendon (LHB) to the labrum with two suture anchors. Fifteen patients (nine men and six women) with an average age of fifty-two years (range, 28–64) underwent biceps tenodesis in the bicipital groove. All patients were reviewed by an independent examiner.
In the reattachment group, the average follow-up was thirty-five months (range, 24–69); three patients underwent subsequent biceps tenodesis for persistent pain, three others were disappointed because of an inability to return to their previous level of sport, and the remaining four were very satisfied. The average Constant score improved from sixty-five to eighty-three points. In the tenodesis group, the average follow-up was thirty-four months (range, 24–68). No patient required revision surgery. Subjectively, one patient was disappointed (atypical residual pain), two were satisfied and twelve were very satisfied. All patients returned to their previous level of sports, and the average Constant score improved from fifty-nine to eighty-nine points.
The results of labral reattachment were disappointing in comparison to biceps tenodesis. Thus, arthroscopic biceps tenodesis can be considered as an effective alternative to reattachment in the treatment of isolated type II SLAP lesions. By moving the origin of the biceps to an extra-articular position, we eliminated the traction on the superior labrum and the source of pain; furthermore, range of motion and strength are unaltered allowing for a return to a pre-surgical level of activity.
The purpose of this study is to report the results of arthroscopic Bankart repair following failed open treatment of anterior instability.
We performed a retrospective review of twenty-two patients with recurrent anterior shoulder instability (i.e. subluxations or dislocations, with or without pain) after open surgical stabilization. There were seventeen men and five women with an average age of thirty-one years (range, 15–65). The most recent interventions consisted of sixteen osseous transfers (twelve Latarjet and four Eden-Hybinette), three open Bankart repairs and three capsular shifts. The causes of failure were additional trauma in twelve patients and complications related to the bone-block in thirteen (poor position, fracture, pseudarthrosis or lysis). All patients were noted to have distension of the anterior-inferior capsular structures. Labral re-attachment and capsulo-ligamentous re-tensioning with suture anchors was performed in all cases with an additional rotator interval closure in four patients and an inferior capsular plication in twelve patients; the bone block screws were removed in eight patients.
At an average follow-up of forty-three months (range, twenty-four to seventy-two months), nineteen patients were evaluated by two independent observers. One patient had recurrent subluxation, and two patients had persistent apprehension. Anterior elevation was unchanged, and loss of external rotation (RE1) was 6°. Nine patients returned to sport at the same level; all patients returned to their previous occupations, including the six cases of work-related injury. Eighty-nine percent were satisfied or very satisfied; the subjective shoulder value (SSV) was 83% ± 23%; the Walch-Duplay, Rowe and UCLA scores were 85 ± 21, 81 ± 23 and 30 ± 7 points respectively. The number of previous interventions did not influence the results. Eight patients (42%) were still painful (six with light pain and two with moderate pain).
Arthroscopic revision of open anterior shoulder stabilization gives satisfactory results. The shoulders are both stable and functional. While the stability obtained with this approach is encouraging, our enthusiasm is tempered by some cases of persistent pain.
Patient outcomes for arthroscopic repairs rotator cuff repairs have been analyzed almost exclusively by means of a single post-operative follow-up date. The purpose of this study was to examine the results of arthroscopic repairs of large rotator cuff tears performed by a single surgeon, both serially and at a two-year endpoint following surgery.
Seventeen patients with retracted U-shaped tears involving the supraspinatus were repaired arthroscopically between June 2002 and October 2003 using marginal convergence suturing followed by tendon-to-bone fixation. Patients were assessed at six weeks, three months, six months, one year, and two years following surgery. Each assessment consisted of a medical history, physical examination, and the Western Ontario Rotator Cuff (WORC®) questionnaire. Evaluation at the two-year study endpoint also included range of motion measurements and a modified University of California Los Angeles (UCLA) scoring system.
During the follow-up period, the three-month average WORC score (63.1%) was the first statistically significant difference from the pre-operation mean of 40.7%. WORC scores peaked at six months post-op (75.5%), and plateaued after this date. The one- and two-year average WORC scores (74.2% and 69.5%, respectively) did not differ significantly from the peak score achieved after six months. At the final two-year follow-up, the average UCLA score was 27.1. Fourteen of seventeen patients (78%) were satisfied with their surgical outcome. When workers’ compensation claimants were excluded from the results, the average UCLA score was 32.0 and patient satisfaction was 100%. There was no significant difference in average range of motion between the surgically-repaired shoulder and the unaffected shoulder.
This study shows that shoulder function improved significantly by three months after arthroscopic rotator cuff surgery and plateaued at six months post-op as measured by the WORC index. There was no statistically significant change in WORC score after six months post-op.
There is an association between SLAP lesions and laxity of the shoulder. The relationship between rotator cuff disease and hypermobility has also been implied. The purpose of this case-control study was to assess the impact of rotator cuff and superior labral pathologies on degree of glenohumeral translation and range of motion of the shoulder in comparison with individuals with normal shoulders.
This study involved individuals with asymptomatic shoulders (control group), and individuals with Rotator Cuff (RC) and Superior Labral Anterior and Posterior (SLAP) pathologies who underwent a repair. Subjects were matched by age, gender and hand dominance side. To assess laxity, all subjects including the control group were examined under anesthesia. The degree of humeral head translation was recorded in three (anterior, posterior and inferior) directions. Range of motion was documented in five directions.
Forty-six females and forty-four males with RC pathology and twenty-seven men with SLAP pathology were compared with the age and gender matched control group. The number of women with SLAP pathology was not sufficient for analysis. Rotator cuff pathology reduced range of motion of the affected side in all directions including flexion, elevation in scapular plane, internal rotation at ninety degrees of abduction and external rotation at zero and ninety degrees of abduction (p=0.02 to p< 0.001) as compared to normal population. Men with SLAP pathology had reduced range of motion in all directions (p< 0.001) except external rotation at ninety degrees of abduction. There were no statistically significant differences in glenohumeral glides between the normal group and SLAP group. However, the affected side of the patients with RC pathology had less laxity than normal population in anterior and posterior directions.
Presence of rotator cuff and superior labral pathologies affect biomechanics and consequently range of motion and accessory movements of the glenohumeral joint. We were unable to confirm a positive relationship between laxity and SLAP and RC pathologies. Prolonged disuse of the shoulder in these pathologies might have played a role in our findings.
This study evaluated the impact of surgical wait-list times on the functional status and productivity of patients with rotator cuff tear
Two hundred and five patients were evaluated by a blind evaluator and by self report when referred for surgical management of cuff tear (confirmed by ultrasound or MRI). Patients were assessed on a monthly basis prior to surgery (two year limit). ROM and strength were assessed by an independent evaluator; patient’s self-reported comorbidity, functional status (WORC, SST), work limitations (WLQ-26) and work lost-time. Changes in health status were assessed using repeated measures ANOVA and GLM.
The mean age of the population used was 56+/−11 years in which 74% were males and 26% females. Tear size was distributed amongst this population as small (0–1 cm {45%), moderate (1–3cm 27%), large (3–5cm 23.2%) and massive (5+cm 15%). Patients had symptoms or an average of fourteen months prior to referral. Despite this, decline in strength (p mental demands) (output demands > time management demands). Loss in productivity exceeded 15%.
Rotator cuff tear causes substantial at work-limitation and work lost time. Patients lost strength and declined in functional status while waiting for surgical repair of a torn rotator cuff. The burden of illness, while waiting for cuff repair its substantial.
Rotator cuff tears are a common cause of shoulder pain and dysfunction. Therefore, the purpose of this in-vitro biomechanical study was conducted to determine the effects of simulated tears and subsequent repairs of the rotator cuff tendons on joint kinematics.
Eight paired fresh-frozen cadaveric shoulder specimens (mean age: 66.0 ± 8.7 years) were tested using a custom loading apparatus designed to simulate unconstrained motion of the humerus. Cables were sutured to the rotator cuff tendons and the deltoid. Loads were applied to the cables based on variable ratios of electromyographic (EMG) data and average physiological cross-sectional area (pCSA) of the muscles. An electromagnetic tracking device (Flock of Birds, Ascension Technologies, VT) was used to provide real-time feedback of abduction angle, to which the loading ratio was varied correspondingly. 2 and 4cm tears were made starting at the rotator cuff interval and extending posteriorly. Specimens were randomised to receive either single or double suture anchor repair. In order to quantify repeatability, five successive tests on each of the intact, torn, and repaired cases were performed. Statistical significance was established using One- and Two-way Repeated Measured ANOVAs (p< 0.05).
Rotator cuff tears caused alteration in glenohumeral kinematics. A 2cm tear caused the humerus to consistently move posterior through the arc of abduction; however, as the tear increased to 4cm the humerus moved anteriorly, returning towards the intact state. Double row suture anchor repairs more accurately reproduced the kinematics of the intact specimen compared to single row suture anchor repair.
The initial posterior displacement in the plane of elevation with the sectioning of the supraspinatus is related to the diminished anterior moment on the glenohumeral joint. As the tear proceeds into the infraspinatus, the anterior and posterior forces become more balanced and a return to near normal intact kinematics was observed. This study demonstrates that double row suture anchor repair more accurately reproduces active shoulder kinematics of the intact shoulder specimens.
This study evaluated the impact of smoking on the surgical outcome of rotator cuff repair controlling for age, gender, and size of tear.
Two hundred and fifty patients were evaluated by a blind evaluator and by self report (SST and WORC questionnaires) at baseline and one year post-op. Types of cuff repair included arthroscopic, mini-open and open procedures. Smoking status was evaluated as a current smoker, quit, or never smoked. Smoking history was subsequently dichotomised into smoker and non-smoker. Generalised linear modeling was used to determine the impact of smoking on surgical outcome using age, gender, and tear size as covariates.
The mean age of the population used was 56+/−11 years in which 70% were males and 30% females. Tear size was distributed amongst this population as small (0–1 cm {44.9%}), moderate (1–3cm {22.7%}), large (3–5cm {15.2%}) and massive (5+cm {17.2%}). All preliminary analyses indicated gender affected tear size and surgical outcomes, and was also associated with smoking status. Due to this confounding effect, males and females were separated for subsequent analysis. The SST questionnaire found smoking to have a significant negative effect on the 1-year l outcomes of males (8.5 vs. 6.1 p=0.025). A similar trend was seen with the WORC (p=0.07). No significant effects were seen for females, but the sample size was underpowered.
Analysis of this population of rotator cuff repairs showed complex interrelationships may exist between gender, age, physical demands and smoking status. The existence of these confounding interrelationships may explain the mixed results seen in the literature concerning smoking and orthopedic procedures. This relatively large cohort established a negative impact of smoking on outcome, after controlling for covariates and confounders. Future research on mediators of cuff outcome should consider potential confounders. Conclusion: Smoking negatively effected surgical outcomes for males but was inconclusive for females. Sex behaved as a confounding variable that masked the smoking effects.
Hemiarthroplasty has been accepted as a viable alternative in the treatment of painful arthritis due to massive rotator cuff failure in patients with well-preserved functional active forward elevation of the shoulder. Unfortunatley, the early clinical results and long-term durability of hemiarthroplasty for rotator cuff tear arthropathy (RCTA) have been inferior to those seen in other disorders, most notably concentric osteoarthritis. Concern regarding the potential need for revision to a reverse shoulder arthroplasty has given rise to the notion of a resurfacing prosthesis as a primary procedure rather than a traditional stemmed-hemiarthroplasty in the hopes of reducing procedural and postoperative complications.
Eleven resurfacing humeral arthroplasties (Global CAP, Depuy) were performed for RCTA as a primary arthroplasty. There were six males and five females, average age of 74.7 years. 36% had undergone previous surgery on the affected side. All had failed a minimum of one year of non-operative treatment prior to surgery. Follow-up averaged eight months (range 4–12).
Prospective mean data analysis showed an improvement in all scales from preoperative baseline levels inclusive of the SST (3.5–6), ASES assessment form (8–17.5), Constant score (49–79) and the DASH (50–27). Mean active forward elevation remained relatively unchanged (one hundred and nine to one hundred degrees), while mean active external rotation improved (thirty-three to fifty-four degrees). Mean computerised muscle testing showed improvement in both elevation (5.1–7.7 N/m) and external rotation strength (2.6–5 N/m). Radiographic analysis has not shown any evidence of implant loosening to date.
Resurfacing humeral arthroplasty seems to demonstrate early favorable clinical results in this group of patients with RCTA. This may serve as an alternative to a stemmed-hemiarthroplasty in these patients and possibly result in a less complicated revision to a reverse prosthesis in the future should this be deemed necessary. Given these results are early, ongoing clincal followup will be necessary to define the longer-term durability of this procedure.
Aim of the study: to determine if WOMAC pain and function outcomes and patient satisfaction are maintained after the institution of a new standardised care pathway for people undergoing primary hip or knee replacement (TJA).
Twenty-three institutions partnered to design and implement a care pathway to provide a seamless transition from acute to rehabilitation sectors by pre-surgery streaming of patients to inpatient or home-LOS were tracked against bench marks of minimum 50% discharged home and an inpatient rehab stay of seven days. Subjects were recruited to the evaluation pre-surgery completing the WOMAC. Follow-up WOMAC and satisfaction questionnaires were completed three months later. The sample of five hundred ensured that the 99% confidence interval (CI) of the mean for each of WOMAC pain and function would be within two and five points respectively of the results of a randomised trial where TJA patients received home-based or inpatient rehabilitation.
On average greater than 50% of people were discharged home from acute care and over 50% of those individuals receiving inpatient rehab were discharged in seven days, with 80% discharged by day ten. 349 (73%) of those accrued (mean age 69 222 females) completed three month follow-up Those discharged home have mean pain and physical scores of 82.7 and 78.7% (where high scores are better pain relief and function) and those receiving inpatient rehab have pain and function scores of 78.6 and 72.4%. These values are within our a priori CI for outcome. 13% reported dissatisfaction with rehabilitation planning and care.
This model of care has achieved the goals of increasing the proportion of people discharged home following TJA and decreased rehabilitation LOS with increased system capacity for rehabilitation. The patient outcomes are maintained.
The purpose of this study was to evaluate outcome following arthroscopic biceps tenotomy or tenodesis for massive irreparable rotator cuff tears associated with biceps lesions.
This is a retrospective study of sixty-eight consecutive patients (mean age 68 ± 6 years) with seventy-two irreparable rotator cuff tears treated with arthroscopic biceps tenotomy (thirty-nine cases) or tenodesis (thirty-three cases). All patients were evaluated clinically and radiographically at a mean follow-up of thirty-five months (range, 24–52).
Fifty-three patients (78%) were satisfied. Constant score improved from forty-six to sixty-seven points (p< 0.001). Presence of a healthy, intact teres minor on preoperative imaging correlated with increased postoperative external rotation (40 vs. 18°, p< 0.05) and higher Constant score (p< 0.05). Three patients with a pseudoparalyzed shoulder did not benefit from the procedure and did not regain active elevation above the horizontal level. By contrast, fifteen patients with painful loss of active elevation recovered active elevation. The acromiohumeral distance decreased 1 mm on average, and only one patient developed glenohumeral osteoarthritis. There was no difference between tenotomy and tenodesis (Constant Score sixty-one vs. seventy-three). A “Popeye” sign was clinically apparent in twenty-four tenotomy patients (61%), but none were bothered by it. Two patients required reoperation with a reverse prosthesis.
Arthroscopic biceps tenotomy and tenodesis effectively treats severe pain or dysfunction caused by an irreparable rotator cuff tear associated with biceps pathology. Shoulder function is significantly lower if the teres minor is atrophic or fatty infiltrated. Pseudoparalysis or severe cuff arthropathy are contraindications.
The purpose of this study was to establish a model to predict the future need for total hip and knee replacement surgery over the next ten years.
Analysis based on queuing theory and Ontario data (Ontario Joint Replacement Registry) considered such factors as changing demographics, specific wait time objectives and changing indicators to predict the future need for THR and TKR up to 2015.
26 725 Ontarians were waiting for THR and TKR surgery on any given day in 2004–05. Each month, the number of new decisions for surgery exceeded the actual number of surgeries by over 20%, adding another five hundred patients to the wait list. We predict that the population > fifty-five years of age will increase by 3.4% annually and that the willingness of patients to consider TJR surgery will increase by 8.7%/year To reduce wait times and establish a steady state of waiting (less than 6 months wait), more than 50 000 surgeries per year must be provided within five years and 70 000 total joint replacements per year by 2014–15 as compared to the 31 448 performed annually at this time. Providing this volume of surgeries means that the number of surgeons will have to double within five to seven years.
The results of this queuing theory analysis predict a substantial need for markedly increased THR and TKR volumes and orthopaedic manpower over the next decade.
Heterotopic ossification (HO) occurs commonly after total hip arthroplasty (THA). Its severe form can result in impaired range of motion with reduced functional outcome. The rate and severity of HO after hip surface replacement arthroplasty (SRA) have never been well studied.
Two hundred and ten hips were randomised to receive uncemented metal-on-metal THA or metal-on-metal SRA. Standard radiographs of the pelvis were assessed for HO by two reviewers at the latest follow-up (minimum of six months), using Brooker severity grading and Kjaersgaard-Andersen regional classification.
The incidence of HO was 38.5% in the SRA group compared to 32.6% in the THA group (p=0.5). However, there was a significant difference in severity grades for the two groups (chi square, p=0.02). According to Brooker’s classification, nearly half of HO was of grade two in SRA and of grade one in THA. SRA was associated with significantly higher rates of severe HO (grades three and four) than THA (12.5% vs. 2.2%; p=0.009). Inter-rater agreement for Brooker grading was excellent (Cohen’s kappa, 0.88; p< 0.01).
The incidence of HO after hip arthroplasty seems to be determined by patient-related factors. However, HO severity appears to be associated with local surgical factors and thereby SRA may result in more severe HO than THA. An extensive surgical approach, additional soft tissue release and the blunt damage occurring in gluteal muscles with SRA may signal the induction of more severe HO. Peri-operative deposition of bone debris derived from femoral head preparation may also play a role by transplanting osteoprogenitor cells. Surgeons must be aware of this risk of severe HO when offering SRA as an alternative treatment to younger patients. Routine prophylaxis with NSAIDs needs to be considered in these patients. A meticulous surgical technique to reduce muscle damage, pulsed lavage to clear bone debris, and debridement of necrotic tissue, may help to decrease the risk of severe HO in SRA.
The purpose of this study was to ascertain the radiographic results of the modified extended trochanteric sliding osteotomy (ETSO), performed by the senior author. The main feature of the ETSO is preservation of the posterior 1cm of greater trochanter and its attached external rotators. Results with this particular osteotomy for revision hip arthroplasty have not been previously reported.
We reviewed forty-eight ETSOs in forty-six patients that underwent revision hip arthroplasty from March 2000 to March 2006. Nineteen osteotomies were for femoral revision alone, and twenty-nine osteotomies were performed for femoral and acetabular revision. All but six (12.5%) had cortical strut augmentation of the osteotomy. The length of the osteotomy, the length of distal fit, the number of wires used were recorded and their relation to union of the osteotomy and femoral stem loosening were investigated.
The rate of ETSO union in this study was 91.3%. Four osteotomies were not united and this was associated with femoral stem subsidence and loosening requiring femoral stem revision in three cases. The rate of femoral stem loosening requiring revision was 8.3%. The length of the osteotomy did not correlate with femoral stem loosening, but a distal fit of less than 9cm was highly significant(p=0.001) with regards to loosening. The use of cortical struts was not protective against osteotomy non-union or femoral stem loosening. Osteotomy union was shown to be dependant on a well fixed (p< 0.0001) and stable stem (p< 0.0001). Three patients dislocated postoperatively (6.5%), and only one of these required revision surgery.
The modified extended trochanteric osteotomy has a low rate of dislocation and a reliable rate of union. We have shown that a well fixed and stable stem is critical to successfully obtaining union of the osteotomy.
We report the outcomes ten to fifteen years after two stage revision for hip infection in one hundred and three patients.
All patients or their next of kin were contacted to determine their current functional status and whether they had required repeat surgery or had recurrent infection. The Oxford-12, SF-12, and WOMAC questionnaires were administered. A comprehensive chart review was undertaken to review the infective organisms, surgery, approach, complications, and need for further revision surgery.
Ten patients had re-infection, six of whom responded to repeat surgery with no further sequelae. Two patients required resection arthroplasty, one patient underwent hip disarticulation after eventual failure of treatment and bone loss, and one immunocompromised patient developed osteomyelitis and was subsequently lost to follow-up. Long-term success rate for two stage- revision is thus 90.3%, or 96.1% with additional surgery. Since then, three patients required revisions for aseptic loosening, one for recurrent dislocation. We were able to follow up forty-one patients, 85 % of whom provided health-related quality of life outcome scores. Thirty-nine patients were deceased, with their outcome confirmed via their last follow-up or with family members, for a total follow-up rate of 78 %. Twenty-three patients were lost to follow-up, but did not undergo further surgery or have reinfections treated at our centre.
Two-stage revision for hip infection, which includes an interim prosthesis of antibiotic loaded cement, offers a predictable and lasting solution for patients with this difficult problem.
The purpose of this study was to evaluate the impact of dalteparin use on transfusion rates and blood loss in patients undergoing primary total joint arthroplasty at our center.
We prospectively studied the transfusion patterns of 1642 patients who underwent primary total hip or knee arthroplasty between January 2004 and December 2005 by five arthroplasty surgeons. The influence of daltaperin use, release of tourniquet in total knee arthroplasty, and the turnover of house staff were analyzed using SPSS V14.0 statistical software.
We identified seven hundred and three total hip and nine hundred and thirty-nine knee arthroplasty patients. The mean haemoglobin drop was statistically significant between 2004 and 2005 (p< 0.001). This was seen in both hip (p=0.014) and knee (p< 0.001) patients. Subgroup analysis of total knee arthroplasty revealed a significant difference in haemoglobin drop between surgeons who released the tourniquet prior to closure compared to release at the end of the case (p=0.005). In addition, there were significant monthly differences that corresponded with the turnover of house staff (p=0.039). Overall, no statistically significant increase in allogeneic transfusion rates was observed between years, months, and individual surgeons.
The use of dalteparin was found to be associated with a significantly increased haemoglobin drop in primary total joint replacement when compared to warfarin. However, the use of dalteparin was not associated with an increase in allogeneic transfusions at our center. The results also suggest that there may be an advantage to releasing the tourniquet and achieving hemostasis prior to closure in knee arthroplasty. Finally, the results emphasise the importance of educating new house staff on methods to reduce intra-operative blood loss and transfusion rates.
The use of wound drains in arthroplasty patients is controversial. Previous work including a meta analysis looking at closed drainage systems has shown no benefit in their use. It is postulated that retransfusion drains may offer an advantage over closed drains and cut allogenic transfusion requirements and aid wound healing. This study was designed to assess the use of retransfusion drains in hip and knee replacement patients and prove the null hypothesis that there is no difference in post op haemaglobin levels or transfusion with their use.
Following an initial pilot audit of blood drainage in such patients we designed a protocol for a prospective trial. In a prospective randomised controlled study we evaluated the use of retransfusion drains in primary hip and knee arthroplasty patients. Eighty patients were randomised to removal of the drain at six or twenty-four hours post op, to assess the most efficient and beneficial use of such drains. The rate of blood drainage, post-operative haemaglobin (Hb) levels, blood transfusion, hospital stay, complications and rehabilitation observed. The two groups were comparable, have a follow up of two years and all attempts to control variables were made.
The drop in haemaglobin, hospital stay, complications and rehabilitation between both groups revealed no significant difference in all respects. Wound healing appeared better in six-hour group for hip and knee patients. There is no effect of type of joint or age on the drop in Hb. The TKR patients drained sig. more blood than the THR patients. The rate of blood loss is discussed. The amount of blood drained that was retransfused was 94% efficient. The allogenic transfusion rates were higher in the six-hour knee group. Three patients required post operative antibiotic but at latest follow up all patients were reported as having no problems and no evidence of infection.
This study concludes that retransfusion drains offer no advantage in the arthroplasty patients’ care.
Antibiotic-impregnated bone cement (ABC) is infrequently used in the North America for primary total hip arthroplasty (THA) due to concerns with cost, performance, and the possible development of antibiotic resistance. The purpose of this study is to examine the cost-effectiveness of using ABC in primary THA for osteoarthritis compared to the use of cement without antibiotics.
A Markov decision model was used to determine if ABC is a cost-effective strategy for primary THA in patients with osteoarthritis. The model tabulates costs and quality adjusted life years (QALYs) accumulated by each patient to evaluate the cost-effectiveness of each strategy. Rates of revision for infection and aseptic loosening were estimated from the Norwegian Arthroplasty Register, and were used to determine the probability of transitioning to a revision arthroplasty for either infection or aseptic loosening. The model was also used to evaluate the cost-effectiveness of ABC when only revisions for infection are considered. Peri-operative mortality rates, utilities, and disutilities were estimated from the arthroplasty literature. Costs were also estimated from the literature using in-hospital resource use as the method of measurement for primary THA. The additional cost of using ABC ($600) was then added to the average cost of the initial procedure ($21,654).
ABC is less expensive and more effective than standard cement when all revisions are considered, making the use of ABC the dominant strategy. When only revision for infection is considered, the use of ABC has an incremental cost-effectiveness ratio (ICER) of $37.335 per QALY compared to cement without antibiotics – which compares favorably with the cost-effectiveness of accepted medical procedures. Sensitivity analyses reveal that for all revisions the additional cost of ABC would need to be greater than $1500, or the average age of patients undergoing primary THA would need to be greater than eighty-three before the use of ABC would cost more than $50,000 per QALY gained. When only revision for infection is considered, the additional cost of ABC would need to exceed $650 before the cost of ABC would exceed $50,000 per QALY gained.
Use of ABC for primary THA is cost-effective over a wide range of assumptions. Notably, when all revisions are considered, ABC is less costly and more effective than use of standard cement over the life span of the patients.
To compare the volume of acetabular bone resection after primary hip arthroplasty with different cup designs and technique of implantation using a computer model.
The factors influencing acetabular bone resection during acetabular cup implantation in THA or hip resurfacing (SRA) include the design of the component and technique of implantation. The impact of these variables on bone resection was simulated with a computer model. A 3-D pelvis was reconstructed from CT scan images. The bony acetabulum circumference was 52.5mm. Implantation of pressfit acetabular component sustaining angles of 165°, 170° and 180° with different wall thicknesses (3.5, 4.0, 5.0mm) at various depths was simulated.
Bone loss of 2742mm3 was calculated for the 165°, 4mm thick, 54mm cup, and deepening of reaming by 1 and 2mm would result in bone loss of 3780mm3 (+38%) and 5076mm3 (+85%), respectively. When oversizing to a 56mm 165° component, 4998mm3 (+82%) of bone was removed. For a 54mm, 5 mm thick component sustaining an angle of 180°, the bone loss would reach 12 410mm3 (+450%).
Acetabular component design has a significant influence on the amount of acetabular bone resection. The surgical technique (avoiding over deepening and oversised components) should minimise bone loss. This knowledge is of particular importance in hip resurfacing since the acetabular component size depends on the selected femoral component size. The knowledge is is also important in THA to minimise bone loss at primary implantation.
Cementless femoral fixation is the gold standard in revision hip arthroplasty. Distal fixation is achieved using either a cobalt chrome or titanium stem. The purpose of this study is to report the long-term survivorship and clinical outcome of a titanium, long-stemmed, load-bearing calcar-replacement femoral component from an independent centre.
Eighty-one patients (average seventy-four years, range thirty-five to ninety-one) underwent hip arthroplasty with the Mallory-Head calcar-replacement femoral component, by a single surgeon. There were thirty-eight males and forty-three females with fifty-four hips initially revised for aseptic loosening, thirteen for peri-prosthetic fracture, and five for infection as a two-stage procedure. The implant was used as a primary device in eight patients with deformed proximal femurs. At most-recent follow-up, radiographic analysis was conducted and clinical outcome scoring was assessed using the SF-12, Harris Hip Score, and WOMAC questionnaire for surviving patients. Complications were also reviewed.
At a mean follow-up of 7.4 years (range four to fifteen), eight patients have died. There was one deep infection, three DVT’s, and two dislocations in the perioperative period. Six femoral stems have ultimately required another revision surgery for aseptic loosening, two for infection, and 1 for implant fracture at a mean of 5.6 years after initial revision. Four patients required removal of the proximal trochanteric bolt due to breakage or loosening. Overall survival of the implant at five years is 95% (CI 0.87–0.98) and 87% (CI 0.72–0.94) at ten years.
The clinical outcome of the Mallory-Head calcar-replacement femoral revision stem is reported from an independent centre. Although the results are encouraging, it would appear that proximal load-bearing fixation with the calcar-replacement stem is not as reliable as distal fixation. The use of a trochanteric bolt was associated with fracture of the greater trochanter or need for a separate surgical procedure for removal. For this series, there was an overall 11% failure rate at a mean follow-up of 7.4 years. The mechanical failure rate is 7.4%. Our overall and mechanical failure rates are somewhat higher than those of the implant developers, who reported 94% overall survival, and a 1.9% mechanical failure rate at a mean follow-up of eleven years.
To evaluate the effect of wait time to surgery on patient derived generic and disease-specific functional outcome following lumbar surgery.
Study cohort of seventy patients undergoing elective posterior lumbar spinal surgery for degenerative conditions. Prospectively collected SF-36 and Oswestry Disability questionnaires administered preoperatively, six weeks, six months, one year postoperatively. Time intervals from onset of symptoms to initial consultation by family physician through investigations, spinal surgical consultation and time spent on the surgical waiting list to surgery quantified. Time intervals compared to patient-specific improvements in reported outcome following surgery using Cox-Regression analysis. The effect of patient and surgical parameters on wait time was evaluated using median time as a reference for patients with either a longer or shorter wait.
Patient follow-up completed in fifty-three (76%). Improvements in patient derived outcome were observed comparing post-operative to pre-operative baseline scores (p< 0.05). The greatest improvements were observed in aspects relating to physical function and pain. A longer wait to surgery was associated with less improvement in surgical outcome (p< 0.05, SF-36 domains BP, GH, RP, VT, and Physical Component Scores). The greatest impact observed was a prolonged surgical wait-list time on SF-36 PCS scores following surgery (Hazard’s ratio 3.53). Patients requiring spinal fusion had a longer wait when compared to those not requiring fusion (p< 0.05).
A longer wait time to spinal surgery can negatively influence surgical results as quantified by patient derived functional outcome measures. Surgery resulted in the greatest improvement in pain severity and physical aspects of function, however, these areas also appeared the most impacted by a longer wait to surgery.
This single incision, anterolateral intermuscular approach (AL-IM) utilises the interval between gluteus medius and tensor fascia lata. The aims of the study were to compare the quality of life, satisfaction and complications of this approach with two of the most commonly used limited incision transmuscular (TM) approaches, namely the mini-posterior (P-TM) and the mini-direct lateral (L-TM).
One hundred and ninety-nine patients receiving MIS THA surgical procedures were evaluated prospectively (63 AL-IM, 68 P-TM and 68 L-TM). The outcome variables were WOMAC function, pain, stiffness, SF-12 (physical & mental), Oxford-12, satisfaction and radiological outcome. Parametric and non-parametric analyses were performed.
There were no significant differences between groups in baseline characteristics including age, sex, BMI, co-morbidity, or pre-op WOMAC, SF-12, Oxford-12 (p> 0.05). However, the AL-IM group was associated with superior outcomes (p< 0.05) in WOMAC function, WOMAC pain, global WOMAC, Oxford-12 and SF-12 physical component.
In the short term the AL-IM approach provides significant improvements in quality of life scores over other limited incision approaches. It provides minimal soft tissue disruption and maintains the abductor musculature and posterior soft tissue envelope, with similar complications and radiological outcomes.
Although many authors have emphasised the importance of lumbar spinal decompression surgery for “leg dominant pain”, there is little objective evidence on the outcomes of surgery for varying degrees of back pain compared to leg pain. Moreover, it is unclear whether patients with radicular or claudication type leg pain, presenting with significant back pain as well, would benefit from surgical decompression. This study evaluated the outcomes of patients with
(i.) leg dominant pain compared to patients with (ii.) leg pain along with significant back pain.
A prospective cohort of consenting adult patients, who have consecutively undergone elective primary posterior lumbar decompression surgery at a single academic institution by sub-specialty spinal surgeons were evaluated with longitudinal follow-up using standardised outcomes instruments. The cohort was analyzed into those with
(i.) leg dominant pain and those with (ii.) significant back pain relative to their leg pain based on pre-operative VAS scores.
Univariate and multivariate analyses were used to adjust for potential confounding effects of demographic, surgical, waiting list and psychosocial factors.
Of the eighty-five eligible patients, sixty-nine (81.3%) had at least one year follow-up with a mean follow-up time of seventeen months. Baseline factors were similar between the two groups except for back and leg pain and wait times for consultation after referral. Patients with significant back pain waited significantly longer (p = 0.04) for consultation after referral than those with leg dominant pain. Significantly (p = 0.002) more patients (93%) in the leg dominant pain group reported clinically significant improvement in the Oswestry than the significant back pain group (59%). This effect remained after multivariate adjustments for other baseline factors.
This study is one of the first to provide objective evidence to support the notion that the primary indication and best predictor of outcome for lumbar decompression surgery is leg dominant pain. Presence of significant back pain, despite presence of leg pain, is a strong predictor of poorer post-operative results. Further research is required to determine if the current long waiting lists are a causative factor for development of significant back pain in surgical candidates.
The purpose of this study was to evaluate the effect of previous femoral osteotomy on the outcome of total hip replacement performed for degenerative arthritis secondary to developmental dysplasia of the hip.
Eighty three primary total hip arthroplasties were performed in sixty-nine patients with osteoarthritis secondary to developmental hip dysplasia (DDH) with a minimum three year follow up. Twenty six hips had undergone previous femoral osteotomy (eleven hips, femoral osteotomy alone (FO); fifteen hips, combined femoral and pelvic osteotomy and fifty-seven hips, no previous surgery. The non operative patients with DDH served as an age and sex matched control group (control). Cementless arthroplasty was performed in seventy-eight hips. The mean duration from femoral osteotomy to primary THA was 22.9 years. The mean follow up was 7.6 years (FO) and 7.2 years (control).
The overall revision rate was 15.4 % (FO) and 21.1 % in the Control group (p> 0.05). Twenty-one hips had one or more complications during or after surgery. The FO group had a higher femoral fracture rate (23.1%) compared to controls (10.5%) (p< 0.05). At latest mean follow-up (7.4 yrs (range, two to sixteen)), the mean Harris hip score was eighty-five (FO) and eighty-five (control group) (p> 0.05). The function and pain scores in the femoral osteotomy group were similar to the controls (p> 0.05). The requirement for bone grafting was similar and operative time significantly greater (FO) compared to controls. The frequency of radiolucent lines around the femoral component in the FO group (36%) was significantly higher than the control group (12.2%) (p< 0.05). Survival analysis was performed with the Kaplan-Meier method. At ten years, the survival of the acetabular component was 84.6%/73.6% and for the femoral component 92.2%/96% in the FO/control group.
Patients with a prior femoral osteotomy have no significant difference in functional outcome, overall complication rate or revision rate compared to controls. However, there is a significant increase in femoral fracture and operative time. Previous femoral osteotomy does not compromise the functional outcome of subsequent total hip arthroplasty.
The purpose of this study was to investigate the efficacy and fusion rates of a unilateral pedicle screw construct supplemented with a translaminar screw in transforaminal lumbar interbody fusion (TLIF). The construct was used with an aim of providing suitable spine stiffness with minimal implant load for spinal fusion.
Nineteen consecutive patients who underwent single level TLIF were included in the study. All patients had posterior spinal instrumentation using a unilateral pedicle screw construct with a contralateral translaminar screw. Patients were assessed preoperatively and at two, six, twelve and twenty-four weeks following surgery and at the end of one and two years. At every visit Oswestry disability index score,Visual analogue scale for pain and a pain diagram were recorded. A radiographic exam was also conducted and CT scan was done if there was concern about fusion.
The average follow up was twenty-four months. There were twelve males and seven females with an average age of forty-eight years. All patients went on to clinical and radiographic union. Sixteen of nineteen patients had significant clinical improvement on VAS for pain, Oswestry scores and pain medication. Three patients had recurrence of radicular pain on the side of the TLIF leading to reexploration. In all three patients solid fusion was observed but scar tissue was evident and symptoms resolved following redecompression of the foramen.
The biomechanical competence of a construct is evidenced by successful fusion. With the advent of minimally invasive techniques to achieve spinal fusion the goal is to use minimal instrumentation without compromising on the final stiffness of the spine. The construct of unilateral pedicle screws supplemented with a trans-laminar screw led to fusion in all our cases. It requires lesser soft tissue dissection and the posterior implants are 56% cheaper.
Spinal surgery in obese and morbidly obese patients can be challenging to the operating surgeon. One of the major problems is obtaining a good surgical access. We have used the synframe retractor system in patients undergoing spinal fusion and have found it especially useful in obese and morbidly obese patients. This study reports our experience.
Seventy-seven consecutive obese and morbidly obese patients that underwent spinal decompression and fusion were reviewed. Patient selection was based on BMI values. Those with a BMI of more than thirty were included in the study. There were thirty-eight females and twenty-five males with an age of twenty-one to eighty-one years. Patient charts were used to acquire information regarding age,weight,height,gender,time in surgery, procedure start and end time,and departure. Postoperative complications and length of hospital stay were also recorded. Anesthesia notes were used to determine ASA scores,number of preoperative morbidities,and intraoperative blood loss. The synframe was used on all the patients. It is a retractor system which consists of a ring placed around the surgical site. It is fixed to both sides of the operating table with arms. Using retractor blades, the ring allows 360 degree access to the surgical exposure from any side.
The set up tme for obese patients was 59.8 minutes and 73.5 minutes for morbidly obese patients. The surgical time and blood loss was only marginally higher in these two groups than in normal weighted patients. The average postoperative length of hospitalisation was 5.8 days. The surgical incision length averaged 7.8 cms for single level and 11.5 for two level fusions. 44% patients suffered a complication. These included cage migration due to a fall, wound infection, dural leak,pulmonary embolism, deep vein thrombosis etc. No significant weight loss was recorded following the surgery.
Obese patients are a surgical challenge due to the comorbidities and difficulty in positioning and gaining good surgical access. The use of synframe retractor system improves surgical access, thereby reducing surgical time and blood loss. The surgical incision length was also comparable to normal weighted patients using this system. No significant weight loss was recorded following surgery. The high complication rate can be attributed to the associated comorbidities.
Although previous studies have shown poor correlation between clinical symptoms due to lumbar stenois and radiologic stenosis, no study has corrected for congenital variation in vertebral body size among individuals. This purpose of this study is to determine the relationship between the degree of radiographic lumbar spinal stenosis, adjusted with an internal control for vertebral body size, and disability from lumbar stenosis.
One hundred and twenty-three consecutive patients with clinical and radiologic confirmation of neural impingement secondary to lumbar stenosis were enrolled prospectively. Thecal sac AP diameter (TSD) and cross sectional area (CSA), and vertebral body AP dimension (VBD) were determined. These parameters were then correlated with patients’ symptoms using the modified Roland-Morris Questionnaire (RMQ) disability score.
This study found no statistically significant inverse correlation between TSD and RMQ score (p=0.433) or CSA and RMQ Score (p=0.124). In addition, there was no significant inverse correlation between CSA/VBD ratio and RMQ score (p=0.036) or TSD/VBD ratio and RMQ score (p=0.109). There was a significant difference in mean RMQ scores when the patients were divided into those with CSA greater than or equal to 70 mm2 and those less than 70 mm2, with T=−2.104 and p=0.038.
The degree of radiographic lumbar spinal stenosis, even with the use of an internal control of vertebral body size and standardized disability questionnaires, does not correlate with clinical symptoms. However, patients with more severe stenosis below a cross-sectional area critical threshold of 70mm2, have significantly greater functional disability.
As the population ages, the prevalence of degenerative spinal conditions is estimated to increase. With soaring healthcare costs, we must be vigilant in our accountability for proper resource allocation to ensure universal access. Significant recent increases in lumbar fusion rates have been observed in the US. Less is known regarding the Canadian experience. Our objective was to evaluate recent trends in lumbar fusion and determine how surgeon factors influence reoperation for spinal stenosis (SS) surgery.
Longitudinal follow-up study of lumbar surgical procedures for SS using administrative databases. Data was gathered on patient-hospital encounters from April 1, 1995 to December 31, 2001. We analyzed trends in spinal fusion. Index procedures (decompressions or fusions) and surgeon variables, such as specialty (orthopaedics, neurosurgery) and volume (above or below thirty cases/year), were selected as predictors of patient reoperation for SS. Adjustments were made for age, gender, and comorbidity. Reoperation rates were evaluated at six weeks, one and two years and until maximal follow-up.
6128 patients were identified (4200 decompressions and 1928 fusions). Proportionally more fusions were performed over the study period when compared to decompressions (1:2.6 in 1995 versus 1:1.5 in 2001). Orthopaedic specialty and higher surgical volume were associated with increased proportion of fusions (p< 0.0001). Reoperation rate was higher for decompressions at two years (OR 1.4) but not at long-term follow-up to ten years. Surgeon specialty had no impact on reoperation rates. Lower surgical volume demonstrated a higher reoperation rate after adjusting for specialty (Hazard Ratio 1.28).
Rates of lumbar spinal fusion have been increasing in Ontario, but at a lesser rate compared with the US. There is wide variation in surgical procedures between surgeon specialty and volume. Surgeon specialty had little impact on reoperation rates. Better long-term survival was observed in spinal surgeons with volumes over thirty cases per year after adjusting for surgeon specialty. Due to increasing rates of spinal fusion, the benefit of improved long-term survival in SS surgery with higher volume surgeons requires more detailed analysis before policy recommendations can be made.
Weight loss is commonly recommended as a treatment for back pain. However, there is little literature to support this. A recent systematic review has identified only studies relating to bariatric surgery. There are no other studies that address whether weight loss improves back pain.
Forty-five consecutive consenting patients were recruited following enrolment in a tertiary multidisciplinary weight management program. These patients were referred primarily for treatment of obesity. The program consisted of consultation and on-going supervision by a sub-specialty weight management physician, and group and individual sessions addressing diet, exercise and behaviour modification. Patients were assessed by independent observers prior to start of program and at twelve weeks into the program with standardised and validated outcomes tools measuring baseline factors, back pain and related functional disability at twelve weeks follow-up.
Prior to starting the program, forty-two patients (93%) reported some degree of low back pain of which 40% rated their pain as moderate (n = 12) or severe (n = 6). Using the Oswestry Low Back Pain Disability Index, 73% patients reported moderate (n = 18) or severe disability (n = 15). At twelve weeks, thirty-seven (82%) patients were available for assessment. There were significant improvement in VAS pain scores (mean change = 1.5, 95% CI: 0.7 to 2.4) and in Oswestry Low Back Disability Index (mean change= 8.6, 95% CI: 3.9 to 13.2). There were significant reductions in the prevalence of moderate or severe back pain (p = 0.04) and moderate or severe disability (p = 0.007) in the entire group.
This is the first study to provide empirical evidence on the positive effects of a weight loss program on back pain. These results lay the groundwork for longer follow-up and comparative studies.
The wait times between referral and initial consultation for a spinal surgeon are amongst the highest in the country. Moreover, the vast majority of patients seen by spinal surgeons are not considered appropriate surgical candidates and hence do not benefit from the surgeon’s expertise in surgical management. Identifying inappropriate patients as a method of “triage” may help reduce the wait times. This paper examines two possible “triage” mechanisms – (i.) questionnaire and (ii.) screening by an acute spine pain centre.
Phase I identified three simple questions, which were reliable at identifying leg and back dominant pain. These questions were independently administered to a consecutive cohort of fifty-two lumbar patients prior to consultation with one of four spinal surgeons at a tertiary academic centre. Phase II involved an acute spinal pain centre, staffed by pain specialists, who have been orientated on appropriate indications for referral. The mandate of this clinic was to assess patients with acute or subacute back pain within two weeks of referral. A similar questionnaire as the one used in Phase I was independently administered to the first ninety lumbar patients attending the clinic in Phase II. All patients were followed independently to determine if surgery was recommended or performed and compared against the baseline questionnaires, findings on CT/MRI scan or pain specialist’s referrals.
The questionnaire identified twenty (38.5%) patients with clearly back dominant pain in Phase I and 56 (62.2%) patients in Phase II. Of the eighteen patients that had surgery or were recommended to have surgery, none had clearly back dominant pain as identified by the questionnaire for a combined sensitivity of 100%. When compared against the patient’s CT/MRI scans in phase I and the pain specialists referrals in Phase II, the questionnaire was more accurate at identifying surgical candidates.
This study has demonstrated in multiple settings that a simple questionnaire of three questions can identify patients requiring surgery and may be more specific than standard referrals, CT/MRI scans, or pain specialist’s assessments. Further work is required to refine this screening process and evaluate it prospectively.
The referral time for spine surgery consultation in Halifax is approximately one year. We currently do not understand the significance of delay in surgical consultation, nor do we have documentation of patient-perceived effects of this delay. Identifying patient characteristics associated with spine pathology mandating earlier surgical intervention would have obvious benefit in streamlining this population in our referral pattern. Furthermore, outlining patient characteristics who are unlikely to benefit from orthopaedic surgical assessment for spine surgery may facilitate community management of spinal pathology and accordingly improve wait times for surgical consultation.
The aim of this study was to Identify patient variables that are predictive of need for early surgical evaluation. Also, to assess patient and surgeon satisfaction with wait times for consultation.
Demographic data and questionnaires were prospectively collected on all consenting patients seen by two orthopaedic spine surgeons over a two week period. Patient and surgeon impression of wait was documented, in addition to Oswestry Disability Index (ODI) scores, and the Visual Analogue Scale (VAS) to document pain. Surgeon reasons for scheduling or delaying surgical planning were also documented and correlated to patient scores.
The average wait time for surgical consultation was 9.7 months, with a mode of sixteen months. 62.8% of patients felt that earlier consultation would be more appropriate, while 31.1% felt that they had deteriorated due to the delay. In addition, 26% felt that the delay negatively influenced their prognosis. Treating surgeons felt that the patient should have been seen sooner in 39% of cases, and that delay in consultation negatively affected prognosis in 6.2% of cases. Of two hundred and forty-two patients completing the survey over the two week period, only ten (4.1%) were scheduled for surgery.
Both patients and physicians felt that prolonged referral-consultation wait times were unacceptable, and deleteriously affected prognosis in a significant proportion of cases. The majority of patients seen were not deemed surgical candidates, indicating room for improvement in referral patterns.
We present our experience with the use of the Anterior Tension Band plate (ATB) following ALIF, which utilises the existing surgical approach obviating the need for posterior fixation. The ATB is a small, smooth, low profile plate. It can be placed through the existing approach (anterolateral retroperitoneal or anterior transperitoneal) across the reconstructed level to prevent extension of the graft space and anterior migration of the spacer. The primary objective of this study is to measure radiographic fusion success in patients with lumbar degenerative disc disease using the ATB system. The secondary objective is to accurately define the clinical benefits to the patient.
This is a prospective multi-center outcome study. Each patient was treated with an ATB plate at one or two levels between L2 & S1 and 1 ALIF or FRA allograft spacer per level. Patient data (VAS Pain, SF-12 and Oswestry) was collected preoperatively, and at six, twelve and twenty-four month post-operative intervals. Fusion was evaluated upon demonstration of bridging trabecular bone through or external to the femoral ring. Secondary endpoint success includes demonstration of 15% improvement over baseline on the VAS, Oswestry and SF-12 patient questionnaires.
To date one hundred and thirty-one patients have undergone surgery. There were ninety-two (70%) single-level ALIF procedures and thirty-nine (30%) two-level ALIF procedures. Patients that have returned for twelve month follow-up (n=41) have had a fusion success rate of 81%. The fusion rate among one-level patients is 89% (n=25) and 67% (n=15) among two-level patients. Four of five of the un-fused two-level patients had one level fused but not the other. At twelve months, Oswestry scores improved by an average of 40% with thirty-one of forty-seven (66%) patients achieving success and VAS scores improved by 42% with thirty-five of forty-seven (75%) being successful.
Preliminary analysis of current data shows positive outcomes using the ATB plating system in ALIF procedures. Primary and secondary outcomes are compatible with current standards of care, and device related complications are minimal. Further analysis of outcome data including will be reported upon the completion of the study.
This study was performed to evaluate the clinical and radiographic outcomes in patients undergoing anterior cervical discectomy and fusion (ACDF) with rhBMP-2 and polyetheretherketone (PEEK) cages with our standard treatment of allograft spacers and demineralised bone matrix.
Forty-six patients who underwent primary ACDF were included in the study. Twenty two patients with PEEK spacers and rhBMP-2 were compared to twenty four patients with allograft spacers and demineralised bone matrix all supplemented with an anterior locking plate. All patients were examined preoperatively and at two, six, twelve and twenty-four weeks and one and two years following surgery. Their cervical Oswestry scores,VAS for neck and arm pain and a pain diagram were recorded at every visit. A radiographic examination was also performed and patients were questioned for dysphagia, hoarseness of voice and any other difficulties. Radiographs were evaluated for prevertebral swelling, bone formation, subsidence and likelihood of fusion. CT scans were performed in any individual at twelve months if there was a concern of non union.
There was no significant difference in pain scores between rhBMP-2 and allograft spacer patients. There was improvement in both groups from their preoperative scores. Incidence of hoarseness of voice was also similar in both groups. There were statistically significant more patients with dysphagia in the rhBMP-2 group at two and six weeks following surgery. All patients in the rhBMP-2 group achieved a radiological diagnosis of probable fusion at their latest follow up (thirty-eight levels). In the allograft group 23/24 patients achieved a diagnosis of probable fusion (39/40 levels). End plate resorption was observed radiologically in 100% of the levels where rhBMP-2 was used. Prevertebral swelling on lateral radiographs was significantly greater in patients with rhBMP-2 causing dysphagia. The cost of implants was three times higher in patients with PEEK cage and rhBMP-2.
The use of rhBMP-2 leads to consistent fusion in the cervical spine. Significantly higher rates of prevertebral swelling, dysphagia and s higher cost are major drawbacks. End plate resorption was an unusual radiographic finding with the use of rhBMP-2.
The primary objective of this study was to determine if surgical treatment for spinal stenosis is comparable to total hip and knee arthroplasty in improving patients’ self-reported quality of life. An age, sex and time of surgery matched cohort of patients who had undergone elective primary one-two level spinal decompression (n=90) with (n=26 /90) or without fusion for spinal stenosis (n=40 with degenerative spondylolisthesis) and elective primary total hip (n=90) and knee (n = 90) arthroplasty for osteoarthritis were compared. The primary outcome measure was the preoperative and two year postoperative Medical Outcomes Study Short Form-36 (SF-36) questionnaire.
There was no significant difference in the mean pre-operative Physical Component Summary (PCS) / Mental Component Summary between groups [Spine −32/43; Hip − 30/45; Knee 31/46 (p > 0.5)]. With the exception of the knee MCS (p=0.2), postoperative scores were significantly improved for all groups [Spine −40/53; Hip − 43/51; Knee 39/48 (p < 0.001)]. Overall the hip surgery had the great impact on PCS and the spine surgery on MCS.
Studies have shown the significant impact on overall patient quality of life and cost-effectiveness of primary total joint arthroplasty. The results of this unique study show that surgical intervention for spinal stenosis has a similar positive effect at two year follow up. This study provides data that supports the need advocacy regarding waiting time initiatives and surgical resources for the treatment of patients with symptomatic spinal stenosis with a similar demographic to those with primary OA of the hip or knee.
The purpose of this study was to determine the prevalence of non-accidental injury in toddlers (birth to two years old) presenting with a femur fracture to a single institution within a Western Canadian population. There are currently no Canadian studies that investigate this association in the medical literature.
A retrospective case-control study was performed for children less than or equal to two years of age with a diagnosis of femur fracture who presented to a single institution from 1994 to 2005. Patients with associated pathological or metabolic bone disorders were excluded. The primary outcome measure was the prevalence of non-accidental injury associated with femur fracture. Secondary outcome measures included: patient demographics, injury characteristics, radiologic and other work-up, and suspicion of abuse. Statistical analysis was performed using tests of analysis of variance and multivariate analysis to identify independent and significant risk factors associated with non-accidental injury.
One hundred twenty-seven children that met the inclusion criteria were identified. The overall prevalence of non-accidental injury was 11% (14/127 patients) and 17% (10/60 patients) in children under twelve months. Mean age was twelve months in the abused group and sixteen months in the accidental group. Forty-three percent of the abused group had delayed presentation compared to 8% of the accidental group. In the abused group, 43% had unknown, unwitnessed, inconsistent histories versus 4% in the accidental group. No specific fracture pattern or location suggestive for non-accidental injury was identified. Forty-three percent (6/14 patients) of the abused group and 12% (13/113 patients) of the accidental group had other injuries. Multivariate analysis determined that delayed presentation (p=0.001), mechanism of injury (p=0.02) and other associated injuries (p=0.003) were the only independently significant risk factors for abuse.
Toddlers who present with femoral fracture are at risk for associated non-accidental injury though perhaps this risk is not as high as previously thought. Regardless, a high index of suspicion is mandatory when these children are encountered and careful screening with a thorough history, physical examination, and other investigations where indicated, are warranted to rule out associated child abuse.
To compare the clinical and radiographic outcomes of Type III supracondylar fractures of the humerus in children managed either by open reduction and internal fixation versus those treated by closed reduction and percutaneous pinning. The indications for open reduction included an inability to obtain a satisfactory reduction by closed means; open fractures and fractures with vascular compromise after closed reduction.
Retrospective chart and radiograph review over a ten year period (1995–2005), with two hundred and thirty-six children with Type III fractures treated at a Level One pediatric hospital within a universal health-care system.
One hundred and seventy by closed reduction and percutaneous pinning and sixty-six by open reduction. The left arm was involved in one hundred and forty-eight cases and twenty-five patients had vascular compromise at presentation but no cases required vascular repair. There were ten open fractures in the open reduction group. The anterior approach was employed in twenty-nine patients, anteromedial in twenty-two and anterolateral, medial and lateral in equal preference. Entrapped structures included brachialis muscle in thirty-four patients, periosteum in eighteen, radial nerve in two, medial nerve in two, and the brachial artery in one. According to Flynn’s criteria, the open reduction group had an excellent or good outcome in 90% of cases while the closed reduction group had an 80% excellent or good outcome.
In this study of displaced Type III supracondylar fractures, there was a higher rate of open reduction than was initially anticipated. There was a higher rate of excellent and good outcomes in the ORIF group but this may be due to a relatively short follow-up in the closed reduction group. Post reduction stiffness would likely dissipate and allow a higher rate of excellent and good outcomes in the closed reduction group. An anterior approach or variation of an anterior approach is best suited to visualise the anatomy and structures hindering the reduction. Despite this, there was no clinical or radiographic difference between the approaches employed. In conclusion, open reduction and internal fixation if displaced Type III supracondylar fractures is a safe and effective procedure. An anterior approach is recommended to identify and relieve the soft tissue obstacles to a suitable reduction. Significance: This study furthers the literature that proposes to lower the threshold for open versus closed reduction of displaced supercondylar fractures in children.
Chronic spastic hip dislocation in patients with spastic quadriplegia can lead to restricted range of movement and severe pain, inability to sit, respiratory and urinary infections, perineal hygiene problems and decubitus ulceration. The Castle procedure is designed to relieve pain and prevent these complications. This investigation evaluates whether the Castle procedure succeeds as a salvage procedure in a pediatric population.
Patients with cerebral palsy who had undergone a proximal femoral resection according to Castle’s description were identified. Exclusion criteria included age over nineteen years at time of surgery, acute hip dislocation, and diagnoses other than cerebral palsy. Eight children completed a chart and radiographic review, and a clinical review. A staff physician evaluated range of motion, apparent discomfort of the child, and the state of the perineal skin. A questionnaire was given the primary caregiver assessing post-operative improvement in pain, sitting duration, infections, ulcers, ease of postoperative care, and overall satisfaction.
Five males and three females with mean age at surgery of 13 ± 1 years, and an average follow-up of 42 ± 13 months were enrolled. All had proximal migration of the residual femur to at least the midpoint of the acetabulum. The average heterotopic ossification score post-op was Brooker one with no symptoms. Five of eight had mild discomfort, with two having moderate to severe discomfort. Five had reduced pain post-op such that they didn’t require analgesics, and were able to sit the entire day. One had a urinary infection post-op, and two had recurrent pneumonias and decubitus ulcerations postop. One child underwent a revision resection for pain and proximal migration, and one was rehospitalised for failure to thrive and pain control. Seven of eight caregivers were somewhat or very satisfied with the procedure, but only five of eight would recommend it to others. Problems identified by the caregivers included treatment failure, difficulty with post-operative care, and significant leg length discrepancy.
The Castle procedure is a successful salvage in severe spastic hip disease, but not universally so. Education concerning potential outcomes and rehabilitation period is also essential in achieving satisfaction.
The purpose of this paper was to evaluate the early results of a new technique for correction of angular deformity in adolescents.
A retrospective review of all patients and radiographs undergoing an open wedge technique of corrective osteotomy employing a special plate designed to keep the osteotomy open at a precise amount was carried out.
From 2000–2005, eleven patients have been treated by the author using this technique. Indications for surgery included adolescent Blount’s disease or Tibia Vara in eight cases, growth arrest after fracture of the proximal tibia in one case, distal tibia in one case and developmental genu valgum in one case. The mechanical axis was restored to normal in ten of the eleven cases. One patient with adolescent Blount’s disease remained in slight varus despite the maximum available correction of 22.5 degrees. All patients healed radiographically in eight to ten weeks. Two patients have had their plates and screws removed after union of the osteotomy because of the high profile construct.
Excellent results can be achieved for correction of angular deformity in adolescents with use of a special plate designed for an open wedge technique. Attention to preserving the opposite cortex at the time of the osteotomy is critical to the success of the procedure. A maximum of approximately 20 degrees of correction is possible with this technique. Early union of the osteotomy and restoration of function give this technique specific advantages over other methods.
To provide a comprehensive radiographic, clinical, and functional description of the shoulder in Apert Syndrome.
A cohort of nine Apert Syndrome patients (ages nine to twenty-seven) followed at a tertiary care facility was included in this prospective study. Patients were clinically assessed with physical examination and completion of two validated functional assessment tools, the Shoulder Pain and Disability Index (SPADI) and AAOS Paediatrics Questionnaire (PODCI). Radiographs were obtained of both shoulders and a standardised protocol MRI was performed on the dominant shoulder of all participants.
All patients had some degree of functional impairment attributable to their shoulder pathology. Physical examination consistently revealed reduced forward flex-ion and abduction. Radiographic findings were similar to previous reports, with pervasive osseous dysplasia of the shoulder joint. Medial humeral head hypoplasia was seen in eight out of nine patients and greater tuberosity overgrowth in seven out of nine patients. MR imaging of the shoulder, not previously performed in a cohort of Apert patients, allowed better delineation of abnormalities seen radiographically such as a central glenoid cleft, seen in eight out of nine patients. It also revealed a new finding of inferior glenoid inclination (seven out of nine patients), which has not been described in the literature. Very few soft tissue or degenerative abnormalities were demonstrated.
The findings of this study confirm that patients with Apert Syndrome are functionally impaired by their shoulder pathology, which may have a similar clinical impact as the more well-described hand and foot anomalies. The global functioning of patients with Apert syndrome is equivalent to patients with juvenile rheumatoid arthritis. The shoulder range of motion in Apert patients is decreased, most significantly in flexion and abduction. Radiographs confirmed previous imaging findings of glenohumeral dysplasia. The novel MRI component demonstrated consistent inferior glenoid inclination, which may be a significant factor in their shoulder impairment. MR imaging revealed no significant soft tissue or degenerative abnormalities to account for their clinical disability. These findings have potential relevance in the surgical and clinical management of these patients.
Serial casting (SC) and Botulinum toxin-A (Btx-A) have been used to treat ankle equinus contractures in cerebral palsy. Previous studies that examined the effects of combining Btx-A injections with SC and either one of the treatments alone in terms of passive ankle range of motion (PROM) have shown mixed results [two-four]. Therefore, the goal of this study is to examine PROM and gait characteristics in children with CP who have undergone SC, either with or without Btx-A injections to the plantarflexors.
Patients who underwent SC +/− Btx-A injections were evaluated for improvement in PROM at the end of treatment. The participants’ age at beginning of SC treatment, Gross Motor Function Classification System (GMFCS) level, treatment duration, PROM, and gait characteristics observed by the treating physiotherapist were obtained from the charts. Only one side per treatment is included in this study (treated side for unilateral treatments, randomly chosen side for bilateral treatments). Table One shows the characteristics of the two groups.
Independent samples t-tests showed that the two groups are similar in terms of age, treatment duration and pre PROM. A repeated measures ANCOVA, using the pre- and post- treatment range of motion as the within subject variables, treatment type as the between subject variable, and GMFCS and age as the covariates showed that the PROM changed significantly regardless of treatment type (p< 0.001). However, the treatment type does not influence the outcome (p=0.411). The changes in range of motion obtained from the two types of treatments were not significantly different using the independent t-test (p=0.957).
Based on these results, it appears that both types of interventions resulted in significant changes in ankle passive range of motion, which is in agreement with Kay et al [4]. Similar ranges of motion at the end of the treatment were obtained from both treatments, and the treatments have similar success rates. Future work is needed to further explore the outcomes associated with serial casting only and Btx-A and serial casting treatments
Clubfoot is a complex three-dimensional deformity that is difficult to assess by clinical examination and conventional radiography. Pedobarography has been established as a useful technique for measuring pressure profiles of the foot, however its utility in the clubfoot population has not been established. The purpose of the present study is to describe the pedobarographic profiles of children with clubfeet and to establish the significant variables when compared with aged-matched controls.
Pedobarographic profiles were obtained using the Tekscan HR Mat Pressure Measurement System and data was analyzed using a custom built LabView program. Clubfoot patients aged 18 months to four years (n = 190) were tested and compared to aged matched controls (n = 82). Each foot was divided into five segments (heel, medial and lateral midfoot, medial and lateral forefoot) and each segment was analyzed for timing of initiation of force, timing of termination of force, force distribution, and impulse. The mean and standard deviation were calculated for each variable. Clubfoot pedobarographic means were compared to the aged matched controls and significant variables were identified using Student’s paired t-test (p < .05).
Nine of twenty-five variables were found to be significantly different in the clubfoot population. The heel showed a reduced force and impulse. The lateral mid-foot showed an increased force and impulse with an earlier initiation and later termination of forces. The medial forefoot showed a decrease force and impulse with a later initiation of force.
Pedobarography has been found to be a useful tool in the evaluation of foot pathology, but its utility in the clubfoot population has yet to be established. In this study, we describe the pedobarographic profiles of children with clubfeet and have noted significant differences when compared to age-matched controls.
The purpose of this study is to assess the clinical outcome and gait analysis of a new technique for ankle arthrodesis using a Fibular Sparing Z Osteotomy (FSZO).
The FSZO technique for ankle arthrodesis utilises a lateral approach where the fibula is osteotomised and reflected posteriorly on a soft tissue hinge to allow easy access to the ankle joint for an anatomic arthrodesis. Outcome assessment at six months follow up included health related quality of life (SF36) and joint specific (American Orthopedic Foot and Ankle Society Ankle-Hindfoot, Ankle Osteoarthritis Scale, Foot Function Index) clinical outcome scores. Gait Analysis was completed using the Walkabout Portable Gait Monitor® which includes a wireless gait belt housing a triaxial arrangement of accelerometers, resting behind the lumbar vertebrae, approximately at position of centre of mass to quatintfy surgery, lurch and functional limb length difference (LLD).
There was a significant improvement in the health related quality of life and the joint specific clinical outcome scores at six months follow up. The six month gait study preliminary analysis showed improvement in some parameters of gait but worsening in others.
The FSZO ankle arthrodesis technique provides improvement in clinical outcome scores and certain gait parameters at early follow up.
To evaluate the gait of five-year old children with club-feet initially treated non-operatively with the French functional technique and to compare these results to the data from this same cohort at the age of two years. Thirty-three patients (fifty-two idiopathic clubfeet) were initially treated with the French functional (physiotherapy) program. At the age of two years, no child underwent surgery for its clubfoot. Gait Analysis was performed with the VICON system (kinematics). At the age of five years, these patients were all re-evaluated in the gait laboratory.
Of the thirty-three patients (fifty-two clubfeet) initially treated non-operatively and tested in the gait lab at two years of age, thirty-seven feet required subsequent surgery by the age of five years. This included posterior release (41%), posteromedial release (35%), tibial osteotomy (19%), and tendo Achilles lengthening (5%). The proportion of feet with the following gait parameters changed significantly (p< 0.05) between the ages of two and five years: Equinus (15% at 2 yrs vs. 2% at 5 yrs), Calcaneus (7% vs. 23%), Foot Drop (18% vs. 4%). The proportion of patients with internal foot progression angle did not change over this time (46% vs. 50%), nor did the proportion with normal sagittal plane ankle motion (61% vs. 54%). At age two years, the majority of patients treated with the French Functional non-operative treatment had normal sagittal plane ankle motion. Gait disturbances, when present at this age, were generally ankle equinus, foot drop and in-toeing. By the age of five years, 71% of these patients underwent surgery for their clubfeet. When re-tested in the gait laboratory at age five years, the proportion of feet with normal sagittal plane ankle motion did not change significantly, however, their resultant gait disturbances, when present, were predominantly calcaneus rather than equinus and foot drop. By treating patients with clubfeet with the French Functional technique exclusively, equinus gait may result in a small proportion.
By subsequently treating these patients surgically after the age of two years, over-lengthening or over-release may occur and result in calcaneus gait. The French originators of this technique now incorporate an early gastrocsnemius fascial lengthening as part of their technique. This modification of their technique should improve the gait characteristics observed at two years of age and should decrease the necessity for late surgery that may have contributed to the gait characteristics observed at five years of age.
Delayed presentation of displaced supracondylar elbow fractures in children is a unique problem, but not uncommon in our hospital settings. The purpose of this study was to evaluate the results of our novel technique of closed manipulation and percutaneous pinning of these late presenting fractures.
We used this technique in fourteen children, with an average age of seven years five months, who presented after an average delay of sixteen days. Through a limited incision technique, manipulation was done using a long curved artery forceps (under image intensifier). Final realignment was obtained and cross k wire fixation done.
At follow-up (average twenty-two months) there were only four children who had cubitus varus greater than one hundred and needed corrective osteotomy. There were no neurovascular injuries. The other two patients with cubitus varus of sixty were satisfied with the appearance of their elbow. Final evaluation was done using Flynn criterion.
The procedure however is quite demanding and needs expertise in closed pinning techniques. Though this technique holds promise in managing the difficult “SUPRACONDYLAR DILEMA”, yet larger series and multicentric trials are needed to establish the efficacy.
Superior mesenteric artery (SMA) syndrome is a rare medical complication of scoliosis surgery. In order to delineate the clinical features, progression and treatment of duodenal obstruction due to SMA syndrome after spinal fusions and to determine the relationship between spinal deformity correction and SMA syndrome, a retrospective study of all patients developing SMA syndrome following spinal fusion was conducted at a tertiary care center.
Charts were reviewed for symptoms of SMA syndrome, type and magnitude of spinal deformity, age at surgery, radiographic correction, complications, and other medical problems. The information gathered was divided according to non-orthopaedic and orthopaedic parameters.
All patients (five female and three male) in this study had spinal fusions performed. Overall, the patients were skeletally mature with a Risser stage average of 3.6. The average correction in the coronal plane was 28.4% in the thoracic spine and 44.6% in the lumbar spine. Sagittal correction averaged 25.9 % and 27% in the thoracic and lumbar spines respectively.. BMI index average was 17.6 (i.e. under-weight individuals). Signs and symptoms of SMA syndrome such as nausea, vomiting, epigastric pain, bloating, and weight loss developed at an average of 11.6 days. Seven patients were managed conservatively, and only one patient required surgery. All patients recovered fully.
This study identified purely asthenic body habitus (low BMI) and significant coronal correction in the lumbar region as risk factors for the development of SMA syndrome after spinal fusion Prolonged nausea and vomiting after spinal fusion requires GI imaging to rule out SMA syndrome, particularly within the first seven-ten days of surgery. Clinicians should also be aware of the possible delayed onset of symptoms in some patients. Nutritional support should be started immediately to prevent further adverse outcomes.
Syndactyly and polysyndactyly of the feet are common congenital conditions of the foot, and surgery to reconstruct the toes may be indicated for cosmetic, psychological, and practical reasons. A dorsal flap is traditionally used for the web space reconstruction, with skin grafts for the bases of the toes. Skin grafting has associated morbidity, and can result in pigmentation mis-match. Single-stage direct closure using a specially designed dorsal pentagonal island flap has advantages including a reduction of morbidity from avoidance of skin grafting, and shorter surgery.
Four patients with six feet were included in the study. There were two cases of syndactyly, and two cases of polysyndactyly. Bilateral involvement occurred in two patients. The average age was eighteen months at time of first surgery. Direct closure was achieved with a dorsal pentagonal island flap with dorsal and plantar triangular flaps. The average duration of follow-up was 19.8 months.
At final follow-up, all patients had acceptable web depth and pulp contour. The distance between bilateral proximal interphalangeal joints of adjacent toes, and the web slope of the reconstructed web space were compared. Complications included partial synechiae, cellulitis and keloid formation.
The dorsal pentagonal island flap is an acceptable technique in providing another means for single-stage reconstruction of the web space in syndactyly and polysyndactyly. Good functional and cosmetic outcomes can be expected. However, the potential complication of keloid formation can affect cosmesis and overall outcome, and must be understood by patients and parents.
Gaining stable fixation in cases of recalcitrant non-unions can be challenging. These cases can be accompanied by a segmental bone defect and disuse osteopenia. One strategy to gain stable fixation is the use of allografts. Both cortical struts and intramedullary fibular allografts have been used for this purpose in the femur, tibia and humerus. The present study aims to compare the mechanical properties a locking plate, an intramedullary fibular strut allograft and a cortical strut allograft in a femur model of segmental bone defect.
A transverse mid-shaft osteotomy was performed in fifteen third generation large composite femurs. Twelve millimeters of bone was resected to create a segmental bone defect. Fixation was undertaken as follows: Construct F (Fibula): Lateral Non Locking plate and Intramedullary Fibula Allograft Construct LP (Locking Plate): Lateral Locking Plate Constrcut S (Strut): Lateral Non-Locking Plate and Medial Cortical Strut Allograft Axial, Torsional and Bending Stiffness as well as Load-to-Failure were determined using an Instron 8874 materials testing machine.
Overall, construct S was the stiffest, construct F intermediate and construct LP the least stiff. Specifically, the S construct was significantly (p< 0.05) stiffer than the two other constructs in the axial, coronal plane bending, sagital plane bending and torsional modes. Construct F was significantly stiffer than construct LP in the axial and coronal plane bending modes only. Both the S construct (6108 N) and the F construct (5344 N) had a greater Load-to-Failure than the LP construct (2855 N) (p=0.005 and 0.001 respectively).
The construct with a lateral non-locking plate and a medial allograft strut was stiffer and had a higher load-to-failure than the construct consisting of a stand-alone locking plate. An intramedullary fibular allograft with a lateral non-locking plate had intermediate characteristics. Other factors, such as anatomic and biologic considerations need to be considered before choosing one of the above constructs. The allograft procedures should only be used once soft tissue coverage has been obtained and any infection eradicated.
Biomechanical stability is important for fracture healing. With standard plate and screw constructs, longer plates with screws well spaced, near and far from the fracture site, are biomechanically superior. Newer locked plates have been shown to be superior to conventional plating for difficult fractures. The ideal screw configuration for fixation with locked plates has yet to be addressed. This study investigates the effects of screw position on construct stiffness as well as strain in both the plate and bone during fixation of a diaphyseal comminuted fracture using a locking plate with bicortical fixation.
A composite cylinder (Sawbones) was machined to produce two models:
(a) comminuted model (4mm gap) and (b) whole model (no gap) to simulate the remodelling phase.
Five strain gauges were mounted to the bone models and one between the center holes of the locking plate. Four different configurations of screw number and position were evaluated using a twelve-hole locking plate (Smith & Nephew Perilock). Plate holes were numbered on each side of the gap from one to six. Screw configuration 654321, 621, 654 and 321 were tested in four-point bending on an MTS 858 Mini-Bionix. Force (N) and displacement (mm) as well as strain readings were recorded at 10 Hz.
Plate strain in the gap model did not vary significantly for the different configurations. Construct stiffness of the 654 model (all screws far from gap) showed a 30% decrease in stiffness as compared to other screw configurations (p< 0.001). In the whole bone model, the maximal bone strain was outside the farthest screw from the center of the plate (stress shielding) and bone strain at the fracture site in 654 was significantly higher than in 621 (p< 0.001).
Results showed that three screw fixation produced similar construct stiffness to a six screw construct when well spaced. Three screws placed far from the fracture gap (654) as compared to three screws evenly spaced (621) showed decreased stability in the comminuted model but resulted in increased bone strain at the fracture site in the whole bone model. All configurations produced similar plate strain.
This study was designed to answer the question “Is there a difference in outcome following operative management of AO type C distal humerus fractures for patients with associated injuries compared to those with isolated injuries?” Our hypothesis was that patients with associated injuries would have worse outcomes compared to those with isolated injuries.
Fifty-eight patients with fifty-eight fractures managed with ORIF were included. Hospital records, clinic notes and radiographs of these patients were retrospectively reviewed. MFA and DASH scores were prospectively obtained after patients were identified (mean 37.4 months post injury, range 6–74 months).
Thirty-two patients had isolated distal humeral fractures while twenty-six patients had distal humeral fractures with associated injuries. The mean MFA of patients with isolated injuries was significantly lower than for patients with associated injuries (27.2 vs 41.7, p = 0.01). There was no difference in DASH scores between the two groups (23.7 vs 29.1, p = 0.34). The mean postoperative arc of motion was one hundred and seven degrees for isolated injuries and seventy-five degrees for patients with associated injuries (p=0.006). Surgical release for stiffness was required for two patients (6%) in the isolated group and ten patients (38%) in the associated injuries group (p=0.003).
Outcomes for isolated distal humeral fractures in this study were comparable to previously published literature. Patients who sustain associated injuries at the time of distal humeral fracture have more stiffness and a worse outcome on a global outcome score, but a similar outcome on a limb specific outcome score.
There is theoretical concern that volar plating has a disadvantage in cantilever bending when axially loaded dorsal to the neutral axis. This has implications for postoperative rehabilitation protocols and overall outcomes related to maintenance of reduction. Most recent biomechanical studies have compared volar locking plates to traditional dorsal non-locked plates. The purpose of this study was to compare the biomechanical stability of volar and dorsal locking plate fixation in a model of dorsally unstable distal radius fractures.
Fourteen synthetic composite radii (Pacific Research Laboratories, Vashon, WA) were used for this study. A dorsally unstable, extra-articular distal radius fracture was simulated by creating a dorsal wedge-shaped defect in the distal metaphysis. Half of the specimens were plated dorsally (n=7) while the other half were plated volarly (n=7) with 2.4mm distal radius locking T-plates (Synthes, Canada). Each specimen was loaded axially in five different positions: central (along the neutral axis of the radius) as well as dorsal, volar, radial and ulnar to the neutral axis using a MTS Sintech 1/G materials testing machine (MTS Systems, Eden Prairie, MN). The plated radii were loaded to 100 N in each position simulating physiological loading during normal range of motion. The main outcome measure was construct stiffness of the plate-bone system (slope of load-displacement curve) for all five loading positions.
Construct stiffness with dorsal locking plates was seven times greater than volar locking plates when dorsally loaded (p < 0.001), 60% greater when centrally loaded (p = 0.055) and 35% greater when volarly loaded (p = 0.029). There was no significant difference in stiffness with any other loading configurations.
The stability of dorsal locking plate fixation is superior to volar locking plate fixation in the setting of large dorsal defects in the distal radius. This is applicable to both fractures with dorsal comminution and dorsal opening-wedge distal radial osteotomies. Further clinical investigation is needed to compare functional outcomes and complication rates between modern dorsal and volar locking plate techniques.
Rapid advances in computer-assisted surgery (CAS) have lead to increasing integration of this technology into the orthopaedic training environment. The real-time feedback provided by CAS improves performance; however, it may be detrimental to learning. The primary purpose of this study is to determine if the form of feedback provided by computer-assisted technology (concurrent visual feedback) compromises the learning of surgical skills in the trainee.
Forty-five residents and senior medical students were randomised to one of three training groups and learned technical skills related to total hip replacement. The “Conventional Training” (CT) group self-determined acetabular cup position and were then corrected with traditional hand-over-hand repositioning. The “Computer Navigation” (CN) group used CAS to self-determine cup position. The “Knowledge of Results” (KR) group self-determined cup position and when satisfied used CAS for optimal repositioning. Outcomes (accuracy and precision of cup placement in abduction and anteversion, and time to position) were assessed in a pre-test, ten minute and six week retention and transfer tests. All retention and transfer tests were performed without CAS.
There were no differences between the groups at pre-test. All groups demonstrated an improvement in accuracy and precision of abduction angle and version angle determination during training (p < 0.001). The CN group demonstrated significantly better accuracy and precision in early training (p < 0.05), and better precision throughout training (p < 0.05). While the CN group demonstrated a decrease in precision during transfer testing it was not found to differ significantly from the other groups. No significant degradation in performance was observed between immediate and delayed testing for any group suggesting no negative effects of the tested training modalities on learning.
In this study the concurrent augmented feedback provided by CAS resulted in improved early performance without a compromise in learning, however, further investigation is required to ensure CAS does not compromise trainee learning. Until this issue is clarified, educators need to be aware of this potential effect.
The purpose for this study was to investigate the site marking practice for emergent and non-emergent orthopedic surgery at the authors’ orthopedic teaching program. One author attended surgeries at two hospitals in 2006, documenting the presence or absence of an unambiguous mark in the prepped and draped surgical field. Although emergent and elective cases were “chosen”, there was no intentional selection bias.
Forty-eight surgeries by eleven surgeons were evaluated. After draping a mark was visible in twelve of eighteen (67%) emergent cases, and twenty-seven of thirty (90%) non-emergent cases. In the nine cases in which no mark was visible, two had been draped out, one had been washed off, two had never been marked, and in four cases the cause was uncertain.
The authors would suggest that surgeons were near fully “compliant” with the COA protocol in non-emergent cases, but “complacent” in emergent ones. Wrong site surgery is an event that results in irrevocable harm to the patient - orthopaedic surgeons should recognise the value of pre-operative skin marking for all procedures, and re-evaluate their own personal practices in light of our results.
A prospective study to examine the outcome of closed fixation technique in managing the unstable, intra-articular fractures of the distal radius by using k-wires only is undertaken.
Sixty-two wrists with unstable distal radius fractures were treated with closed manipulation and closed pinning of the fracture. Ten are between fifty-one and eighty-one years old and fifty-two are below fifty years of age. Both readial styloid and the dorsal cortex of the distal fragment provided the entry points. All fractures were reduced with fingfer trap traction. Tran osseous and intra-medulaary pinning was carried out in all the fractures. In this two step technique, first the radial articular surface is stabilised. Then, axial stability is provided by trans-epiphyseal intramedullary nails. Emphasis was laid on the reduction, complications and fracture healing.
All fractures healed. A ‘concentric’ collapse varying from 1 to 3 mm was seen in twenty-six cases. No loss of reduction was seen. Surprisingly, no cutaneous radial nerve injuries, no tendon related complications were seen. Five pins in three patients were loose and were removed betweeen seven to thirty days. None had repeat surgeries.
Sound technique is key to success. The longer the collective length of the intra- medullary pins the greater remained the stability of the fracture construct. Ulnar bone provides as a pillar to assemble the distal radius. Fracture of the distal ulna (not merely a fracure of the ulnar styloid) required an additional support in the form of an external fixator in only two patients. Since the follow-up is not very long (mean six months), the author contends to say that the short term results are rewarding with this technique. The unsatisfactory results reported in literature from the closed pinning is largely from inadequate fixations used. When proper technique is applied the radial articular surface is held on the distal shaft to permit only a minimal collapse that is concentric; and compression at the fracture site promoting excellent healing is the rewarding result.
We aimed to quantify the sample sizes and magnitude of treatment effects in a review of orthopaedic randomised trials with statistically significant findings.
We conducted a comprehensive search (PubMed, Cochrane) for all randomised controlled trials between 1/1/95 to 12/31/04. For continuous outcome measures (ie functional scores), we calculated effect sizes (mean difference/standard deviation). Dichotomous variables (ie infection, nonunion) were summarised as absolute risk differences and relative risk reductions (RRR). Effect sizes > 0.80 and RRRs> 50% were defined as large effects.
Our search yielded 433 RCTs, of which 76 RCTs with statistically significant findings on 184 outcomes (122 continuous/62 dichotomous outcomes) met study eligibility criteria. The mean effect size across studies with continuous outcome variables was 1.7 (95% confidence interval: 1.43–1.97). Almost one in three results, despite being reported as statistically significant did meet the definition of a large effect size (ES< 0.80). For dichotomous outcomes, the mean risk difference was 30% (95%confidence interval:24%–36%) and the mean relative risk reduction was 61%.
Malunion following displaced fractures of clavicle most commonly occurs with shortening and anterior rotation of the distal fragment. This results in scapular malalignment, which has been documented clinically as scapular winging. However, to our knowledge, this scapular malalignment has never been quantified radiographically. The purpose of our study was to quantify the radiographic parameters in patients with symptomatic midshaft clavicle malunions demonstrating scapular winging.
Fourteen patients with symptomatic midshaft clavicle malunions demonstrating scapular winging of the affected shoulder were identified. Each patient underwent CT scanning of both clavicles and scapulae. A standardised CT protocol was used for each patient. Multiple measurements were used to document the clavicle malunion and scapular malalignment including clavicular length, the distance from the tip of the scapula to the chest wall and to the nearest adjacent spinous process, and the relative height of each scapula on the chest wall. Statistical analysis using the Student t-test was performed.
The mean time from fracture was twenty-nine months. There were eleven males and three females with a mean age of 33.1 years. The mean clavicular shortening was 17mm (P> 0.001). The mean anterior-rotation through the malunion was nine degrees, and showed a trend toward significance (P=0.1). The distal fragment was anteriorly translated 13.5mm (P> 0.001) relative to the opposite normal shoulder. The scapula was displaced laterally 10.3mm (P> 0.001) from the nearest spinous process, superiorly 16.3mm and 12.2mm (P> 0.001) off the chest wall on average compared to the opposite normal shoulder.
Patients with symptomatic clavicle malunions often complain of periscapular pain, and winging of the scapula has been noted in such individuals. Ours is the first study to document and quantify scapular malalignment in this clinical setting. Since most shoulder musculature is scapular based, identification and quantification of scapular malalignment may have important ramifications in decision-making regarding treatment of clavicle fractures and malunions.
The purpose of this study was to analyse the twenty to twenty-five year outcomes of one hundred and ninetyfive cemented, matte finish, HD-2 THRs performed in one hundred and sixty-six patients with osteoarthritis of the hip by two surgeons.
The one hundred and ninety-five THRs (one hundred and sixty-six patients) were followed prospectively by clinical assessment using the Harris Hip Score (HHS) and radiographic analysis.
One hundred and forty-nine patients (90%) died with their implant still functioning or still had a successful implant at twenty to twenty-five years follow-up. Ten patients (6%) underwent a revision for aseptic loosening of the acetabular (n=2, 1.2%) or femoral (n=4, 2.4%) component, or both (n=4, 2.4%), that was related to wear-induced osteolysis. 7 (4.2%) patients (eight hips) were lost to follow-up. The mean HHS at the latest follow-up (twenty to twenty-five years) was 88±9. Radiographically, twenty-nine (85%) of the acetabular components were well fixed and four (12%) were probably or possibly loose. Two hips (6%) had probable or possible loosening of the femoral component. At twenty five years, the calculated cumulative survival rate (Kaplan-Meier method) revealed excellent results for revisions (83%±6, any cause) and aseptic loosening (86%±6, femoral component, 93%±3, acetabular component).
The surviving patients had a good mean follow-up and radiographic fixation, proving the exceptional long-term success of this implant.
This study reports on the clinical and wear performance of a prospective randomised controlled trial comparing highly cross-linked (XLPE) to conventional polyethylene (PE) in total hip arthroplasty at five years minimum follow-up.
One hundred patients enrolled in a prospective randomised controlled trial received identical hybrid total hip arthroplasties with the exception of the polyethylene insert. Fifty patients received a PE liner (2.5 MRads; gamma-in-nitrogen sterilization) and fifty patients received a XLPE liner (10Mrads; gas-plasma sterilization). Clinical outcomes were determined using Harris Hip, WOMAC and SF-12 scores by an independent study nurse. Femoral head penetration rates were determined using a validated radiographic technique (Hip Analysis Suite 8.0.1.1) based on radiographs at six weeks, one year and yearly post-operatively. Linear regression analysis was performed for both the entire polyethylene groups and on each patient, where the slope represents the steady state head penetration rate (after bedding in) from one to five years follow-up.
None of the patients were lost to follow-up, however, nine patients were deceased before their five year follow-up. Two patients have been revised for loose stems. At average follow-up of 6.0 years (range 5.1–6.8 years), there were no differences in Harris Hip, WOMAC or SF-12 scores. XLPE had a significantly lower (p= 0.03) steady-state head penetration rate of 0.018 mm/year compared to 0.050 mm/year for XLPE (approximately 64% reduction). Analysis of individual patient’s head penetration rates demonstrated a similar significantly lower rate with XLPE (0.004 ± 0.067 mm/year) compared to PE (0.045 ± 0.083 mm/year). Interestingly, when examined by gender, the male PE group had a significantly higher head penetration rate (0.081 ± 0.084 mm/year) than both the male and female XLPE (−0.013 ± 0.104, 0.011 ± 0.074 mm/year, respectively).
At minimum five years follow-up, there were no clinical differences between groups. After bedding-in, there was a significant lower head penetration rate with XLPE compared to PE. Thus, mid-term follow-up appears to demonstrate a significant wear reduction (based on head penetration rates) afforded by first generation XLPE. Long-term follow-up is required to demonstrate the clinical benefit of this new material.
We conducted a prospective randomised controlled trial to compare functional outcomes, complications and reoperation rates in elderly patients with displaced intra-articular distal humerus fractures treated with open reduction internal fixation (ORIF) or primary semi-constrained total elbow arthroplasty (TEA).
Twenty-one patients were randomised to each treatment group. Two patients died prior to follow-up and were excluded from the study. Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand (DASH) scores were collected at six weeks, three months, six months, twelve months and two years. Complication type, duration, management, and treatment requiring reoperation were recorded.
Five patients randomised to ORIF were converted to TEA intraoperatively because of extensive comminution and inability to obtain fixation stable enough to allow early ROM. This resulted in fifteen patients (three male, twelve female) with an average age of seventy-seven years in the ORIF group and twenty-five patients (two male, twenty-three female) with an average age of seventy-eight in the TEA group. MEPS was significantly improved at three months (82 vs 65, p=0.01), six months (86 vs 66, p=0.003), twelve months (87 vs 72, p=0.03) and two years (86 vs 73, p=0.04) in patients with TEA compared with ORIF. DASH scores showed a significant improvement for TEA compared with ORIF between six weeks (43 vs 77, p=0.02) and six months (31 vs 50, p=0.01) but not at twelve months (32 vs 47, p=0.1) and two years (34 vs 38, p=0.6). Reoperation rates for TEA (3/25) and ORIF (4/15) were not statistically different (p=0.2).
TEA for the treatment of comminuted intra-articular distal humeral fractures provides improved functional outcome compared with ORIF.
Elevated intracompartmental pressure (ICP) results in muscle damage. Previous studies identified severe inflammation associated with elevated ICP. This study was designed to determine whether indomethacin, a potent anti-inflammatory agent, reduces muscle damage secondary to elevated ICP. We hypothesised that administration of indomethacin reduces muscle damage from elevated ICP.
Sixteen adult Wistar rats were randomised to four groups. In group One (control), no intervention occurred. Group Two (indo) rats were administered indomethacin (12mg/kg) with no elevation of ICP. Group Three (CS) rats had elevated ICP (30–40mmHg X 45 minutes) using saline injection. Group Four rats (CS/indo) had elevated ICP and indomethacin administration. After forty-five minutes, hindlimb fasciotomy was performed. The extensor digitorum longus muscle was reflected onto an intravital microscope. Capillary perfusion was measured by comparing the number of continuously perfused capillaries to intermittent and non perfused capillaries. Inflammation was determined using the number of activated (rolling and adherent) white blood cells. Muscle cell damage was measured using differential fluorescent staining. Perfusion, inflammation, and muscle damage were compared in all four groups using a one-way ANOVA (p< 0.05).
Perfusion: Indomethacin treatment (CS/indo) increased the proportion of intermittently perfused capillaries (39.1 ± 2.2 vs 30.3 ± 2.7) and decreased nonperfused capillaries (38.4 ± 1.8 vs 50.1 ±2.5) compared to CS (p=0.0002). Control and indo groups demonstrated more continuously perfused capillaries compared to CS or CS/indo groups (p< 0.0001). Muscle damage: Indomethacin treatment of elevated ICP reduced the proportion of damaged cells from 0.20 ± 0.14 (CS) to 0.01 ± 0.0.005 (CS/indo, p< 0.0001). There were no differences between CS/indo, control, or indo groups. Inflammation: CS and CS/indo groups demonstrated greater inflammatory activation compared to control and indo groups (p< 0.001). There were no differences in inflammatory activation between CS and CS/indo (p> 0.05).
Treatment of elevated ICP with indomethacin improved microvascular perfusion and reduced cell damage. The protective mechanism of indomethacin is unknown, but may be related to an anti-oxidative and vasodilatory effect. Treatment of elevated intracompartmental pressure with indomethacin dramatically reduces muscle damage and may have important future clinical benefit.
The complications of prostheses for fractures of the proximal humerus are understudied because the experience of each shoulder surgeon is limited and a standardised registration protocol is not yet available. A prospective study on complications in shoulder arthroplasty for fracture is, therefore, essential to explore variables that influence outcome. The purpose of this study is to report our experience with complications following arthroplasty for proximal humeral fractures.
In a multicenter study, four hundred and six patients treated with arthroplasty for proximal humeral fracture were prospectively followed during a nine year period; three hundred patients with a minimum of two years follow-up, at an average of forty-five months (range, 24–117), were available for review. Objective results were graded with the Constant score and range of motion. Subjective results were reported according to patient satisfaction.
At follow-up, the average Constant score was fifty-four points (range, 14–95) and active forward elevation was 103° (range, 10°–180°). Eighty-one percent of patients were satisfied or very satisfied. We observed a 59% rate of late (after three months) complications, including a high rate of tuberosity-related complications (72% malunion or nonunion). Initial tuberosity malposition was present in 35% of the patients. Secondary migration despite initial good positioning was observed in 24%.
Tuberosity complications were associated with poor final Constant score, poor range of motion and shoulder pain (p=0.001 for all items). A re-operation was performed in 5.3% of the cases. Patients who were mobilised according to the ‘early passive motion’ concept had double the incidence of secondary tuberosity migration, compared to those that were initially immobilised (14% versus 27%, p=0.004). Tuberosity complications are the most frequent late complication and they are associated with poor functional results. It is, therefore, incumbent upon the surgeon to maximise healing with adequate fixation of the tuberosities, followed by sufficient immobilization.
The ideal bearing surface for total hip arthroplasty is still an area of debate.Increasing numbers of total hip replacements are being done in the younger patient population.Ceramic-on-ceramic bearings have gained popularity due to their low wear rate.However, ceramic fractures with subsequent catastrophic failures have been reported. This study reports on early results of ceramic-on-ceramic total hip replacements.
This is a study analyzing a prospectively collected data for seventy-five ceramic-on-ceramic total hip replacements with minimum follow up of eighteen months. Average age at time of surgery was forty-seven years. This study focused on the complications of this ceramic population. Complications included: One posterior dislocation, two intra-operative calcar fractures that needed wiring, one intra-operative fracture of the acetabular liner, two cases of impingement (one which resulted in a revision), and one periprosthetic fracture. The two patients that required further surgery were the periprosthetic fracture after a fall and one for component impingement. No revisions were performed for loosening or catastrophic failures. No wear, loosening, or osteolysis was seen on radiographs. The SF-12, WOMAC, and Harris Hip scores were not significantly different from other reported hip series.
Ceramic-on-ceramic bearing surfaces in total hip arthroplasty are a safe option with outcome equivalent to standard THR in the short term. Ceramic Hips may provide a more durable prosthesis, especially in young and active patients. Intra-operative technical guidelines that may enhance the quality of the results will be presented and fully disclosed.
Metal on metal hip articulations are associated with the release of cobalt and chromium ions. There are few published reports of these levels following hip resurfacing arthroplasty. This study was undertaken to determine cobalt and chromium ion levels following hip resurfacing arthroplasty.
Ninety-one patients were prospectively entered in a study assessing ion levels following hip resurfacing arthroplasty. Serum, erythrocyte and urine cobalt and chromium levels were measured. Samples were collected preoperatively then at three months, six months and yearly thereafter. Each sample was analyzed with an ICPMS assay machine.
Preoperatively the median values for serum, erythrocyte and urine cobalt and chromium levels were all within the normal range. Median serum cobalt levels increased from baseline (0.1 ug/l) to 1.1 ug/l at one year and 1.6 ug/l at two years. Median serum chromium levels increased from baseline (0.2 ug/l) to 1.9 ug/l at one year and 3.3 ug/l at two years. Median erythrocyte cobalt levels increased from baseline (0.1 ug/l) to 1.0 ug/l at one year and 1.3 ug/l at two years. Median erythrocyte chromium levels increased slightly from baseline (1.0 ug/l) to 1.2 ug/l at both one and two year follow-up. No correlation was seen between ion levels and patient activity, implant position, clinical scores or BMI. No clinical effects of elevated ions were observed. Outliers of either cobalt or chromium were seen in twelve patients (13%) in the series.
Hip resurfacing arthroplasty is associated with significant elevations of cobalt and chromium ions. An increase in serum levels of both cobalt and chromium has been noted at two years. This trend also occurs with erythrocyte cobalt but not with erythrocyte chromium. There is a close correlation between serum and erythrocyte cobalt levels but not between serum and erythrocyte chromium levels. We recommend using serum cobalt and serum chromium measurements as a standardised method of ion analysis following metal on metal hip replacement. This allows for capture of maximal levels of both ions in vivo. Further study is required to determine if any clinical effect will be seen as a result of these elevated ions.
Hip resurfacing arthroplasty has become a popular treatment option for younger active patients. The early published results from designing surgeons/centers have been favourable. We undertook a prospective multi-center trial to determine the outcome of hip resurfacing arthroplasty at independent centers. The clinical, radiographic and functional results were assessed.
A prospective IRB approved study was initiated in July 2003 to assess the outcome of hip resurfacing arthroplasty using a contemporary design implant. (Conserve Plus - Wright Medical Technology) Disease specific (Harris Hip Score/WOMAC) and global (Rand self assessment index) outcome measures were used. Radiographs were reviewed for component position and migration as well as any signs of lysis or loosening. Complications and re-operations were recorded.
A total of one hundred and eighty-eight patients have been enrolled in the study to date. One hundred and four patients have a minimum one year follow-up and forty-six patients have a minimum two year follow-up. Mean Harris Hip Scores (pre-op, one year, two years) were fifty-five, eighty-nine and ninety-one. Mean WOMAC pain scores were forty-seven, ninety and ninety. Mean WOMAC stiffness scores were forty, seventy-eight and eighty-two. Mean WOMAC function scores were forty-six, eighty-seven and eighty. RAND physical function mean scores were thirty-three, seventy-six and seventy-six and the RAND physical limitations mean scores were nineteen, sixty-seven and seventy-five. Radiographic analysis showed average cup abduction to be forty-six degrees (range twenty-six to sixty-three). Average femoral stem position was one hundred and thiry-eight degrees (range one hundred and eighteen to one hundred and fifty-seven). Nine patients have been revised to date (4.8%). Four for acetabular loosening, two for neck fracture, one for femoral loosening, one for impingement and one for persistent pain. There have been eight other patients requiring re-operation without revision. Medical complications occurred in fifteen patients.
Early results have demonstrated a good return of function in patients with hip resurfacing arthroplasty. A high early revision rate (4.8%) was seen in our study. Technical factors appear to be the main contributor to the high early complication rate. Hip resurfacing is associated with a steep learning curve. We continue to utilise hip resurfacing in select patients but recommend caution for those who are new to the technique.
We performed a prospective, randomised, blinded clinical trial comparing metal versus polyethylene bearing surfaces in patients receiving a THA.
Forty-one patients were randomised to receive a metal (twenty-three) or a polyethylene (eighteen) insert with identical femoral and acetabular components. The metal bearing was a 28mm low carbon on high carbon couple. Patients were evaluated pre-operatively, at three, six, twelve months and annually thereafter, including an evaluation of erythrocyte and urine cobalt, chromium, and titanium, outcome measures (WOMAC, SF-12, Harris Hip Score) and radiographs.
No patients were lost to follow-up. At an average 7.2 (range 6.1 – 7.8) years follow-up there were no differences in any outcome measures or radiographic findings. Patients receiving metal liners had significantly elevated metal ion measurements. At most recent follow-up, compared to the polyethylene control group, patients receiving a metal on metal bearing had erythrocyte cobalt levels were eleven times elevated (median 1.4 μg/L (metal) vs 0.12 μg/L (poly), p< .001). Urine cobalt levels were thirty-nine times elevated (median 11.4 μg/L/day (metal) vs 0.29 μg/day (poly), p< .001) and urine chromium levels were twenty-eight times elevated (median 4.75 μg/day (metal) vs 0.17 μg/day (poly), p< .001). Additionally the metal ion levels reached an early steady state level and did not decrease over time. (Erythrocyte Co (μg/L): 1.29 (6 mos), 1.20 (1 yr), 1.0 (2 yr), 1.10 (3 yr), 1.35 (4 yr), 1.40 (5 yr)).
Both cobalt and chromium ion measurements were significantly elevated in the blood and urine of the patients randomised to receive the metal on metal THA at all time intervals. Contrary to previous reports, in 34% of patients with a metal liner, metal ion (erythrocyte cobalt) elevation was still increasing at latest follow-up, and in the overall metal on metal patient cohort, metal ion median levels were not decreasing over time. As in polyethylene wear data, metal ion results are not necessarily generalizable, but are bearing design specific.
Hip surface replacement is an alternative for young patients considered for hip replacement. The in vivo release of ions from these surfaces has yet to be well evaluated. In the present study, we compared the concentrations of metal ions in blood of patients with hip surface replacement and metal-on-metal (MM) total hip arthroplasty (THA).
Blood was collected six months and one year after implantation time into Sarstedt Monovette® tubes for trace metal analysis from patients having Articular Surface Replacement (ASR®, DePuy Orthopaedics; n=61), 28 mm-head MM THA (n=18), and 36 mm-head MM THA (n=25). The concentrations of cobalt (Co), chromium (Cr), and molybdenum (Mo) were analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS). Since metal ions are potent inducers of oxidative stress, total antioxidant, peroxide, and nitrotyrosine levels (oxidative stress markers) were also measured in plasma of the patients.
The median Co and Cr levels progressively and significantly increased in the three groups during the first year post-operation (compared to patients without hip bearings (n=25)). After six months, the levels of Co and Cr were significantly higher in patients with ASR and 28 mm MM THA than in patients with 36 mm MM THA. There was no difference after one year. The level of activity, as measured by the UCLA activity score, was higher in ASR patients than in 28 and 36 mm MM THA after one year. No differences were observed for Mo levels in these patients when compared to our control group. There was no increase of oxidative stress marker levels in patients with ASR and 36 mm MM THA and no correlation between the concentrations of Co and Cr ions and the levels of oxidative stress markers.
Our results show that, at one year post-operation, the concentration of ions in patients with ASRs is similar than those in patients with MM THAs. Moreover, results suggest that metal ions liberated from MM bearings do not induce damage to macromolecules by oxidative stress in plasma of patients. Longer follow-ups are still required to characterise the concentration of ions in ASR and to determine conclusively the effects of elevated circulating ions.
Plate fixation of the proximal humerus fractures may now be more desirable with the use of a biological approach by limiting surgical insult and allowing accelerated rehabilitation by a solid fixation. To evaluate the safety and efficacy of minimally invasive plating of the proximal humerus using validated disease-specific measures.
During a period of one year, thirty patients were operated with use of the LCP proximal humerus plate (Synthes) through a 3cm lateral deltoid splitting approach and a second 2 cm incision at the deltoid insertion. The axillary nerve was palped and easily protected during insertion. Only two-part (N=22) and three-part impacted valgus type (N=8) were included in this study since they can be reduced indirectly thru this percutaneous technique. The average follow-up was thirteen months (eight to twenty months). All patients had the Constant and DASH evaluations.
All fractures healed within the first six months with no loss of correction. The surgical technique was found easy by all surgeons, the axillary nerve was palpated and protect with this new technique. No infection or avascular necrosis were seen. No axillary nerve deficit was identified. At the last follow-up (average nineteen months, twelve months minimum), the median Constant score was sixty-eight points, with an age ajusted score of seventy-six. The mean DASH score was twenty-seven points. Only age was independently predictive of both the Constant and DASH functional scores. Patients improved until one year of follow up.
Percutaneous insertion of a locking proximal humerus plate is safe and produces gives good early functional and radiologic outcomes. Recuperation from a proximal humerus fracture can be seen until one year.
This prospective observational study was designed to report the soft tissue complications after fixation of tibial plafond fractures in an effort to challenge the current recommendation that a seven centimeter skin bridge represents the minimum safe distance between surgical incisions. Our hypothesis was that many of the skin bridges would be less than seven centimeters and that this would not result in an increased incidence of wound complications.
All injuries received surgical treatment using a minimum of two surgical approaches for the tibial plafond and the associated fibula fracture (if applicable). Forty-two adult patients with forty-six tibial plafond fractures were enrolled in the study between July 1, 2004 and Dec 30, 2005. There were 1 A1, 3 B1, 2 B3, 6 C1, 6 C2 and 28 C3 fractures. Forty-four plafond fractures had an associated fibular fracture. There were thirty-six closed and ten open fractures. High energy injuries were managed using a two staged approach consisting of fibular ORIF through a posterolateral approach combined with spanning external fixation, followed by tibial ORIF when soft tissue swelling subsided (forty-four fractures). The surgical approaches used, the length of the incisions, the distance between the incisions (size of the skin bridge), and the overlap between the incisions was recorded. The surgical wounds were followed until healing and for a minimum of three months.
Two surgical approaches were used in thirty-two fractures and three approaches were used in fourteen. These one hundred and six surgical incisions produced sixty skin bridges. The approaches used included pos-terolateral (forty-four), anterolateral (thirty-nine), medial (eleven), anteromedial (eight), and posteromedial (four). The mean skin bridge size was 5.9 cm. Only 15% of the skin bridges were > 7 cm, while 70% were 5–7 cm, and 15% were < 5 cm. The mean overlap between incisions in the study was 7.9 cm. One hundred two incisions healed uneventfully. Healing of two anterolateral incisions was complicated by eschars that resolved with local wound care. One posterolateral fibular incision failed to heal until the fibular plate was removed. One patient required subsequent surgical procedures for infection.
Despite a measured skin bridge of less than seven centimeters in 85% of instances, the soft tissue complication rate was low in this group of patients. With careful attention to soft tissue management and surgical timing, incisions for plafond fractures may be placed less than seven centimeters apart, allowing the surgeon to optimise exposures based on the pattern of the injury.
Screw fixation of the injured syndesmosis restores stability, but may reduce ankle motion. We wished to determine whether functional and radiographic results are improved by removal of syndesmosis screws. In addition, we studied whether large fragment screws have an advantage compared to small fragment screws. We hypothesised that retained intact syndesmosis screws are detrimental to ankle function.
One hundred and seven adults with ankle fractures requiring syndesmosis screw fixation between 2001 and 2005 were retrospectively studied. Indications for syndesmosis fixation were a positive intraoperative external rotation stress test or inadequate lateral column buttress. Weight bearing was encouraged six weeks postoperatively. Syndesmosis screws were only removed for tenderness, prominence or ankle dorsiflexion < 0.05.
The LEM score for patients with intact screws was 70 ± 26 compared with 85 ± 20 for broken, loosened or removed screws (p=0.05). The OM score for patients with intact screws was 48 ± 36 compared with 63 ± 27 for broken, loosened or removed screws (p=0.12). There was no difference in outcome comparing broken, loosened, and removed screws. The tibiofibular clear space for intact screws was 3.3 ± 1.3 compared with 4.1 ± 1.7 for removed, broken or loosened screws (p=0.02). There was no difference in outcome comparing large and small fragment screws.
Patients with broken, loosened or removed syndesmosis screws have better functional outcome compared to intact screws. The syndesmosis allows fibular rotation, shortening and translation during gait; the presence of an intact syndesmosis screw may restrict this motion. There was no disadvantage to leaving broken or loosened screws in-situ.
Metal-on-metal (MOM) hip resurfacing devices are known to release metal ions locally and into the systemic circulation. Previous studies suggest that larger prosthetic head size will correlate to reduced wear properties and may result in lower systemic release of metal ions. This project assessed the effect of femoral head size on serum cobalt (Co) and chromium (Cr) levels in subjects after unilateral hip resurfacing with the Cormet 2000 prosthesis.
We prospectively collected patient characteristics, outcome, and serum samples from device implanted subjects at six months, one, two, and three years following surgery. Serum Co/Cr levels were determined using high-resolution inductively coupled plasma mass spectrometry. Students t-test was used to compare ion levels in two groups based on femoral head size.
Thirty-five subjects (twenty male) were followed. Co/Cr levels were increased at all time points when compared to control levels. A significant negative correlation was observed between Co and Cr levels and femoral head size. Co/Cr levels in subjects with larger femoral heads were significantly lower when compared to those implanted with smaller heads (Co, −35.8%; Cr, −33.0%). This correlated with significantly higher Co/Cr levels in females versus males, with females receiving significantly smaller heads on average.
Elevated serum Co/Cr levels were observed at all time points following implantation and in females and in subjects with femoral heads.
The purpose of our study is to determine if hamstring autograft size can be predicted preoperatively. We will define a relationship between patient body size (BMI, height, and weight) and harvested graft size, as well as define a relationship between the preoperative MRI cross-sectional area (CSA) of hamstring tendons and harvested graft size. This information will be useful as a tool for preoperative planning in graft choice selection.
The pre-operative MRIs of one hundred and four patients (62M, 42F) who underwent ACL reconstruction using hamstring autografts were analyzed. Cross-sectional area (CSA) of the ST and G was measured on a single axial MRI image at the level of the knee joint. Combined CSA of both tendons was then compared to the diameter of the four-strand hamstring autograft measured intra-operatively. Patient BMI, height and weight was also compared to intraoperative hamstring autograft size. Linear regression analysis was then performed to define the relationship and predictive value of body size on graft diameter.
Mean graft size was 7.4mm (range 6 – 9). Average graft size for men and women, 7.6mm and 7.1mm, respectively. Predicting graft size from BMI: r= 0.29, R2= 0.08. Predicting graft size from height: r= 0.52, R2= 0.27. Predicting graft size from weight: r= 0.5, R2= 0.25. On preoperative MRI, the mean CSA of ST and G was 9.8mm2 (range 5.4 – 17.7) and 4.5mm2 (range 1.8 – 9.4) respectively, with a total CSA of 14.3mm2 (range 8.4 – 25). If the total CSA was greater than 12mm2, a graft of 7.0mm or greater could be predicted 93% of the time, with sensitivity and specificity, 78% and 76%, respectively, and a LR of 3.25.
Body size is a poor predictor of hamstring graft size in ACL reconstruction, and therefore a large patient does not always provide a large graft from harvested hamstring tendons. MRI assessment of hamstring tendons can be a useful tool for preoperative planning, providing a strong predictive value of graft size from a simple calculation.
Previous research suggests knee joint moments and muscle activity during walking are altered in patients with anterior cruciate ligament (ACL) deficiency and in patients with medial compartment knee osteoarthritis (OA). The objective of this study was to compare knee joint flexion and adduction moments and the extent of quadriceps-hamstring muscle co-contraction before and one year after combined simultaneous ACL reconstruction and high tibial osteotomy (HTO).
Eighteen patients (three females, fifteen males; age = 40 ± 8 yrs.; BMI = 28.8 ± 5.77) with ACL deficiency and OA affecting primarily the medial compartment of the knee underwent ACL reconstruction (hamstring autograft) and medial opening wedge HTO procedures during a single operation. All patients completed pre-operative and one-year postoperative quantitative gait assessments. Three-dimensional kinetic and kinematic data were collected during self-paced walking and used to calculate the peak external flexion and adduction moments about the knee. Electromyographic (EMG) activity was collected from the hamstrings and quadriceps and used to calculate the co-contraction ratio. Peak moments and co-contraction ratios were compared pre and postoperatively using paired t-tests.
The peak knee flexion moment decreased from 2.31 ± 1.14 to 1.33 ± 0.73 %BW*ht (p=0.001); mean decrease = 0.98 %BW*ht (95%CI: 0.49–1.47). The peak knee adduction moment decreased from 2.81 ± 0.62 to 1.69 ± 0.61 %BW*ht (p< 0.001); mean decrease = 1.12 %BW*ht (95% CI: 0.80–1.43). The quadriceps-hamstring co-contraction ratio decreased from 0.82 ± 0.14 to 0.72 ± 0.18 (p=0.056); mean decrease = 0.10 (95% CI: −0.003 – 0.21).
The present findings suggest that combined simultaneous ACL reconstruction and HTO significantly decreases knee flexion and adduction moments during walking. Although the present findings suggest that the quadriceps-hamstring co-contraction ratio also decreases, future research with more patients is required to confidently evaluate potential changes in muscle activity. These findings are consistent with an overall reduction in dynamic knee joint load.
The purpose of this study was to evaluate functional outcome following supracondylar femur fractures using patient-based outcome measures.
Patients having sustained supracondylar femur fractures between 1990 and 2004 were identified from the fracture databases of two level-one trauma centres. Three patient-based outcome measures, the Short Form-36 (SF-36) Version two, the Short Musculoskeletal Functional Scale (SMFA), and the Lower Extremity Functional Scale (LEFS) were used to evaluate functional outcome. Each patient’s medical record was also reviewed to obtain information regarding potential predictors of outcome, including age, gender, fracture type (AO classification), presence of comorbidities, smoking status, open vs. closed fracture, and occurrence of complications. Univariate and multivariate models were then used to identify significant predictors of outcome, as reflected in the SMFA bother and dysfunction scores.
Sixty-one patients (thirty-five males and twenty-six females) with an average age (at time of injury) of 53 ± 18 years consented to participate. The average length of follow-up was 64 ± 34 months from the time of injury. Mean SF-36 V2 scores were lower than Canadian population norms indicating decreased function or greater pain, while mean SMFA scores were higher than published population norms indicating greater impairment and bother. The mean LEFS score was 40.78 ± 15.90 out of a maximum score of eighty. At the univariate level, the presence of complications was a significant predictor of both the SMFA bother (p=0.002) and dysfunction scores (p=0.015), while positive smoking status was a significant predictor of the bother score (p=0.002). Based on a multivariate linear regression model, the presence of complications (p=0.013) and positive smoking status (p=0.011) were both significant predictors of a higher SMFA bother score. In the multivariate model for SMFA dysfunction score, the presence of complications (p=0.014) and the presence of comorbidities (p=0.017) were significant predictors of a higher score.
Comparing SF-36 and SMFA scores with published population norms, supracondylar femur fractures were associated with residual impact. Based on our analysis, smoking, the presence of medical comorbidities at the time of fracture, and the occurrence of complications following fracture repair were the main predictors of poorer patient outcomes following supracondylar femur fracture.
Summary Results of this two-group parallel design randomised controlled trial indicated one and two year outcomes following ACL reconstruction were not different in one hundred and fifty patients using either an ACL functional knee brace or neoprene knee sleeve. Introduction: The primary objective of this study was to compare postoperative outcomes in patients using an ACL functional knee brace and patients using a neoprene knee sleeve
One hundred and fifty patients were randomised to receive an ACL functional knee brace (n=76) or a neoprene sleeve (n=74) at their six week postoperative visit following primary ACL reconstruction. Patients were instructed to wear the knee orthosis during participation in all physical activities. Patients were assessed preoperatively, six weeks, six, twelve, eighteen and twenty-four months postoperatively. Outcome measures included disease-specific quality of life (ACL QOL), KT 1000 and single limb forward hop test administered by a blinded research assistant. One and two-year outcomes were compared after adjusting for baseline scores. A priori directional subgroup hypotheses based on time from injury to surgery, pre-operative KT 1000 scores, and one and two-year compliance scores were evaluated using tests for interactions. Analysis was completed on an intention-to-treat basis.
There were no significant between-group differences for any of the outcomes at one and two-year follow-ups. Mean between-group differences at two years were: 2.87% (95% CI: −3.85 – 9.60) for the ACL QOL, 0.07mm (95% CI: −0.80 – 0.93) for KT 1000 side-to-side difference, and 2.64% (95% CI: −4.57 – 9.85) for hop limb symmetry index. There were no significant subgroup findings and adverse events were similar between groups.
Confidence intervals for between-group differences are narrow and exclude clinically important differences. These findings suggest a functional knee brace does not result in superior outcomes over a neoprene sleeve following ACL reconstruction.
ACL deficiency can have detrimental pathological effects on the menisci in the knee. A database review in Quebec over a three-year period was previously reported (Canadian Academy of Sport Medicine, Winnipeg, 2003), which examined the relationship between waiting times for ACL surgery and the requirement of a meniscal procedure. The purpose of this study is to determine if the length of time between an index injury and ACL reconstruction (ACLR) surgery correlates with the incidence of meniscal repair and meniscectomy in Alberta, and to compare the results to those of the Quebec study.
Retrospective study, using procedure and billing codes to search the Alberta Health and Wellness databases for knees undergoing primary ACLR surgery between 2002–2005. Inclusion: Patients sixteen years or older at time of reconstruction. Exclusion: Revision ACLR, duplicate billing and coding, and insufficient database information. For each reconstructed knee, databases were searched for initial injury evaluation date with primary care physician, dates of meniscectomy or meniscal repair procedures, and date of ACLR.
Over a three-year period, there were 3382 primary ACL reconstructions performed in Alberta, 3812 ACLR in Quebec. Of these patients, 2583 in Alberta (76%) and 1722 in Quebec (45%) required a meniscal procedure. On average, Albertans waited 1389 days from injury to ACLR compared to 422 days in Quebec. In Alberta, patients not requiring a meniscal procedure waited 1212 days, patients requiring meniscal repair waited 1143 days, and patients requiring meniscectomy waited 1519 days, compared to 251, 413 and 676 days in Quebec, respectively. Three percent of patients in Alberta had ACLR < three months after injury (114 patients), with 45% requiring meniscectomy. Overall, 61% of patients in Alberta required a meniscectomy for significant meniscal injury, compared to 48% of patients in Quebec. The proportions for each province were statistically significant.
Compared to Quebec, patients in Alberta are waiting longer for ACLR, with only a small proportion of cases being treated acutely. The proportion of patients requiring surgery for significant meniscal injury is also greater in Alberta. The higher proportion of patients in Alberta requiring meniscectomy may be due to the delay in ACLR.
The purpose of this study was two-fold:
to examine perioperative prospective changes in pain, disability and psychosocial variables in ACL reconstructed recreational athletes over the pre-op to eight week post-op period. to see what variables will predict greatest disability at eight weeks post-op.
All participants were recreational athletes at the time of their injuries who had patella-autograft procedure at the the Queen Elizabeth II Health Sciences Centre. Fifty-four patients (twenty-nine males; mean age = 25.4 years, SD = 8.08). Mean education was fourteen years (SD = 2.08), 32%(17) were married, 67%(36) single, and 1% was divorced. 94%(51) of the sample was Caucasian, 3%(2) Black, and 1% Asian. One quarter reported their ACL injury was due to sport-based contact, with non-contact sporting activity reported at 76%(41). All participants completed measures of pain, depression, pain catastrophizing, state anxiety pre-op, on days one and two following surgery and again at eight weeks post-op. Disability was assessed pre-op and eight weeks post-op.
Pain was varied across comparisons with preoperative pain increased twenty-four and forty-eight-hour post-op. Pain at forty-eight-hours postoperative was significantly higher than pain reported at eight-weeks post-op. Catastrophizing did not differ from the pre-op to twenty-four-hour post-op but did drop from twenty-four to forty-eight-hours and forty-eight-hours to eight-weeks post-op. Pre-op depression increased twenty-four-hour post-op, but not from twenty-four to forty-eight-hours and declined at eight-weeks. Anxiety increase pre-op to twenty-four-hours but not from twenty-four to forty-eight-hours but did drop from forty-eight-hours to eight-weeks.Disability did not change over time. Regression showed age or gender did not predict disability but forty-eight hour pain and catastrophizing did.
These data indicate that pain and psychological variables change over time of ACL recovery. Results suggest that pain and distress peek during acute post-op period. As well, post-op catastrophizing predicts disability at eight weeks post-op which may indicate that catastrophizing may be related to behaviours related to slower recovery following ACL reconstructive surgery.
The dorsal interosseous muscle (DIM) may be indicated in the coverage of small defects of the hand as a proximally or distally based muscle flap. The objective of his two-part study was to define the vascular supply of the interosseous muscles of the hand, and to identify the dominant arterial pedicle of each muscle for potential use of these muscles as muscle or musculocutaneous flaps.
A radio-opaque injectate (lead oxide, gelatin and water mixture) was injected into the femoral artery of 10 fresh cadavers. The intrinsic muscles of the hand were meticulously dissected along with their vascular pedicles, removed and radiographed. The number, type, diameter of vascular pedicles of muscles and their distribution were analyzed. The area of the vascular territory supplied by each source vessel was calculated.
Ten embalmed cadavers were injected with red latex into their axillary arteries and a similar dissection protocol was followed.
Vascularisation of the interosseous muscles is by palmar metacarpal arteries of the deep palmar arterial arch and dorsal metacarpal arteries. In addition to these constant axial blood supplies, there are rich perimuscular plexus from adjacent nutrient arteries. The origins and insertions of the muscles are also supplied by very fine vessels from this plexus. The diameters of the dominant branches ranged from 0.6 to 1.4 mm (mean 1.0 mm). The vascular territories of the dorsal metacarpal and common palmar arteries extend along the medial and lateral parts of the dorsal interosseous muscles.
The dorsal interosseous muscle or musculocutaneous flap are more useful than other intrinsic muscles of the hand because the DIM are easily accessible via the dorsal hand and can be split distally or proximally, and a split musculosseous flap based proximally or distally on the dorsal metacarpal artery can be performed. The functional defect in the donor site after an interosseous muscle flap transfer of the second and third interosseous space is tolerable. This anatomic study provides further information to help design various flaps from the hand for local transfer. The authors describe a thirty-two-year-old male patient in whom the third dorsal interosseous muscle was used as a distally based myocutaneous flap to reconstruct a defect in the hand.
This study was undertaken to assess the influence of anthropometric measurements on the graft thickness obtained at anterior cruciate ligament reconstruction surgery.
Data from fifty one consecutive patients who had undergone ACL reconstruction by the same surgeon using double loop hamstring grafts were analysed. The body mass index, height and weight of these patients were correlated with the graft thickness obtained during surgery using non parametric tests (Spearman’s correlating coefficient).
There was a statistically significant positive correlation between the body weight and graft thickness (r = 0.32, p=0.02, n= 51). There was however, no correlation between the body mass index and height with the graft thickness.
Anthropometric measurements do not have as much influence on the thickness of the graft as would have been assumed, in ACL reconstruction surgery. Although the body weight has a positive correlation, the body mass index and height do not seem to have any appreciable influence on graft thickness.
Recurrence represents the leading complication of arthroscopic anterior shoulder stabilization. Even with modern suture anchor techniques, a recurrence rate of between 5 to 20% persists; emphasizing that arthroscopic Bankart repair cannot apply to all patients and selection must be done. Numerous prognostic factors have already been reported, but strict observance would eliminate almost all patients from arthroscopic Bankart repair. We hypothesised that clinical and radiological risk factors could be present and identifiable in the normal outpatient visit, and they could be integrated into a severity score
A case-control study was undertaken, comparing patients identified as failures after arthroscopic Bankart repair (i.e, recurrent instability) with those who had a successful result (i.e., no recurrence). Recurrence was defined as any new episode of dislocation or any subjective complains of subluxation. During a four-year period one hundred and thirty-one consecutive patients with recurrent anterior shoulder instability, with or without shoulder hyperlaxity, were operated by the senior shoulder surgeon with an arthroscopic suture anchor technique and followed for a minimum of two years. Patients were excluded if concomitant pathology, including multidirectional instability, were present. Bony lesions were not excluded. A complete pre and postoperative questionnaire, physical exam, and anteroposterior x-ray were recorded. Mean follow-up was 31.2 months (range, twenty-four to fifty-two months).
Nineteen patients had a recurrent anterior instability (14.5%). Preoperative evaluation demonstrated that age below twenty years old, involvement in athletic competition, participation in contact or forced-overhead sports, presence of shoulder hyperlaxity, Hill-Sachs lesion visible on AP external X-ray, and loss of inferior glenoid sclerotic contour on AP x-ray were all factors related to increased recurrence. These factors were integrated in an Instability Severity Index Score and tested retrospectively on the same population. Patients with a score of six or less had a recurrence risk of 10% and those over six had a recurrence risk of 70% (p< 0.001).
This study proved that a simple scoring system based on factors of a preoperative questionnaire, physical exam, and anteroposterior x-ray can help the surgeon to select patients who would benefit from arthroscopic stabilization with suture anchors and those for whom an open surgery, like the Latarjet procedure, is a better option.
To examine the effect of gender on outcome of high tibial osteotomy (HTO) for varus gonarthrosis at a minimum two year follow-up
Sixty-five patients (twenty-four female and forty-one male) participated in this investigation. Mean age at the time of surgery was fifty-five years and mean time to follow-up was 54.83 months. Multiple linear regression was used to estimate the strength of the association between post-operative WOMAC osteoarthritis index scores and the independent variables of gender, age, BMI, time (months from surgery) and pre and post operative mechanical axis angles (MAA) measured on standing double-leg hip-to-ankle radiographs.
This analysis revealed that none of the independent variables contributed significantly to the WOMAC outcome scores.
The results of this study indicate that gender is not a significant predictor of outome following medial opening wedge HTO. This is contrary to the view held by many.
To determine union rate in complicated nonunions of the scaphoid treated with a vascularised bone graft.
Vascularised bone grafting for scaphoid nonunions (1–2 ICSRA, Zaidemberg technique) has shown initial enthusiasm. Its usefulness has been challenged in cases where the proximal pole of the scaphoid is avascular. Complicated nonunions where the proximal pole is highly likely to be avascular occur in revision surgery and proximal pole nonunions.
Fourteen patients were retrospectively followed up. Eight had nonunion following previous scaphoid surgery (two previous ORIF, two previous nonvascular grafting, and four with two previous surgeries). Six patients had no previous surgery for a proximal pole nonunion of 12.5 months’ duration. All patients were male with an average age of twenty-four. Delay from fracture to vascularised bone grafting was twenty months. Graft harvesting was done according to the Zaidemberg technique by two orthopaedic surgeons. CT-scan was used to confirm union in all patients except two who were lost of the follow-up. Twelve patients were followed up by an independent surgeon at a postoperative minimal period of four months. Functional status was assessed with the DASH questionnaire and follow x-rays were performed to determine the presence of degenerative changes.
Union was confirmed by CT-scan in eleven of twelve followed patients (92%) at an average time of six months following vascularised graft. Radio-scaphoid osteoarthritis was seen in the one patient that didn’t achieve union.
This series suggests that the Zaidemberg graft is useful and may be proposed in situations of revision surgery and proximal pole non-unions. We achieved a high union rate in these complicated nonunions even though there was high likelihood that the proximal pole was avascular. This study stresses the importance of protective immobilization until documented union by CT-scan in this difficult subset of patients.
A primary mode of failure for total elbow arthroplasty is osteolysis caused by wear debris. Loading of the polyethylene components by off-axis bearing loads is the likely cause of this debris. Load transfer at the elbow is affected by many factors, including the state of the radial head. New implant designs provide the option to use the intact, resected, or implant reconstructed radial head. However, the effect of the radial head state on stability and loading has not yet been investigated in these new implant designs.
We postulated that the presence of the native or prosthetic radial head would reduce the wear-inducing loading patterns experienced by the humeral component and improve joint stability compared to when the radial head is resected.
Seven cadaveric upper extremities, amputated at the mid humerus, were tested in a joint motion simulator equipped with an electromagnetic tracking system to quantify motion. Simulated active flexion was tested with the arm in the dependent position. Passive elbow flexion was conducted with the arm in the varus and valgus gravity-loaded orientations. After testing the intact elbow, the collateral ligaments were sectioned and a linked Latitude ulno-humeral joint replacement was performed (Tornier, Stafford, TX). The humeral component was instrumented with strain gauges for measuring varus-valgus bending and internal-external torsion. Ulno-humeral kinematics and humeral component loading were measured when the radial head was intact, resected, and following radial head arthroplasty.
An increase in varus-valgus laxity was noted following replacement of the ulno-humeral joint with the prosthesis (p< 0.05). There was no difference in joint laxity between the intact radial head, radial head excision or radial head arthroplasty (p> 0.05). Torsion moments increased, while bending loads decreased in the humeral component following radial head excision and were restored following radial head arthroplasty (p< 0.05).
No significant effect of radial head state on varus-valgus joint laxity was observed for the linked ulno-humeral prosthesis. In the absence of collateral ligaments, the observed post-operative increase in varus-valgus laxity can be attributed to the difference in laxity between the native joint and the articular components of the linked implant. Load transfer was altered by radial head excision, which may affect the magnitude of bearing wear and the incidence of aseptic loosening. Further studies are required to determine whether these changes in load transfer influence wear of the polyethylene components or implant loosening.
Management of comminuted, intra-articular distal radius fractures remains a challenge. Basic principles are to obtain anatomic reduction, maintain the reduction, and rehabilitate the injured joint and the patient as soon as possible. This report presents fragment specific fixation as a method for maintaining fractures reduction and allowing early otion.
This was a retrospective consecutive series of AO classified C2 and C3 distal radius fractures treated with fragment specific fixation. Patients were included if their age was between eighteen and sixty years. Part one was a radiographic assessment of seventy-two patients after fracture union. Part two was a comprehensive functional assessment, carried out by a blinded observer in the first twenty-three patients, six months post op.
Mean patient age was thirty-nine years. The most common combination of fixation was a radial pin plate with an ulnar pin plate, although twenty-eight different combinations were found. Part one (radiographic) results were mean final radial inclination angle 21°, mean final palmar tilt 3.7°, mean final ulnar ariance +0.7mm, mean final intra-articular gap 0.9mm, mean final intra-articular step 0.7mm. Part two (functional) results were mean grip 21kg; mean key pinch 10kg; mean ranges of motion pronation 74°, supination 69°, extension 59°, flexion 48°, radial deviation 17°, ulnar deviation 22°; and mean return to work twenty-one weeks. Mean scores in Patient Rated Wrist Evaluation and Disabilities of the Arm, Shoulder, and Hand were twenty and fourteen, respectively.
In the short term, the functional results of ragment specific fixation of ifficult distal radius fractures produced results similar to other methods described in the medical literature. The technique, however, allowed early wrist motion, and produced long term radiographic results well within Cooney’s criteria for optimal reduction. It is expected, therefore that long-term results will prove to be superior to other management techniques.
This
Six fresh upper-extremities were mounted in a motion simulator with tracking system, which enabled both passive and simulated active elbow flexion. The intact elbow was tested then the LCL was sectioned from its humeral origin and repaired with a transosseous suture technique. Locking sutures were placed in the LCL and passed through a humeral bone tunnel entering at the centre of curvature of the capitellum with exit holes in the lateral epicondyle. An actuator pulled on the sutures to achieve 20, 40 and 60 N of LCL repair tension and the sutures were then secured. The dependent variable of this study was the motion pathways of the ulna relative to the humerus. The data were analyzed using a two-way, repeated-measures ANOVA with relevant
With the arm oriented in the horizontal position under varus gravity loading, the repairs tracked in greater valgus than the intact LCL regardless of the repair tension. The larger the initial repair tension, the more the elbows tracked in valgus. Initial tension of 60 N was statistically different than the intact LCL with the forearm in pronation (p=0.04). Both the 40 and 60 N initial tensions were statistically different than the intact LCL with the forearm in supination (p< 0.01).
Repair of the LCL using transosseous sutures effectively restores the varus stability of the elbow. The initial tension of LCL repairs affects the kinematics of the elbow, with a tendency to over-tighten the ligament and pull the elbow into valgus. These data suggest that acute repair of the LCL should be performed using a transosseous suture technique, and that a tension of 20N or perhaps less is sufficient to restore stability.
Spontaneous flexor tendon ruptures of the hand are uncommon and the current understanding of these ruptures is incomplete.
The purpose of this study is to report five cases of spontaneous flexor tendon rupture in the hand, and to contrast the findings to those in the literature.
A retrospective review of patients with flexor tendon injuries referred to our hand surgeons identified five patients who sustained a spontaneous rupture of the flexor digitorum profundus tendon. A literature search found a total of nineteen articles describing spontaneous tendon ruptures that met our criteria.
We report five cases of spontaneous rupture involving the flexor digitorum profundus tendon. One case involves an abnormal intertendinous connection between the ring and small finger profundus tendons and another involves a lumbrical muscle variant. To our knowledge, the latter has not been reported in association with spontaneous tendon rupture. In reviewing the literature for spontaneous flexor tendon ruptures, a total of fifty spontaneous ruptures in forty-three cases was found. The majority involve the profundus tendon of the small finger in the palm. The ruptures most often occur during periods of peak strain, but can also occur without identifiable trauma.
This study provides a detailed overview of spontaneous flexor tendon ruptures in the hand not found in the literature. The pathogenesis of spontaneous tendon ruptures is still unclear and is likely multifactorial. Although spontaneous flexor tendon ruptures of the hand are uncommon, these ruptures occur more often than one might recognise.
The purpose of this study was to determine if there is a relationship between ultrasound measured gap size and functional outcomes in non-operatively treated achilles tendon ruptures.
Patients who presented with complete achilles tendon ruptures were prospectively randomised to operative or non-operative treatment groups and followed over a one year period. The non-operative patients were selected and reassessed at three months, six months and one year. Patients were included if seen within seven days of their injury and had ultrasound confirmation of a complete tear. Non-operative treatment consisted of a functional bracing protocol with an aircast boot. Ultrasound measures included tear location and gap size in neutral, dorsiflexion, and plantar flexion of the ankle. Outcome measures were re-rupture rates, complications, range of motion, calf circumference, strength, and functional outcome scores.
Twenty-five patients were included with complete data. The mean plantar flexion gap was 5.6(+/−7.5mm). The mean dorsiflexion gap was 13.7(+/−12.5mm). Proximal tears were found in 41% of patients, midsubstance in 27%, and distal tears in 32%. At one year follow-up 71% of patients had excellent results with the remaining 29% showing good results. Isokinetic strength, range of motion, and calf circumference measurements were all greater than 90% relative to the contralateral extremity. There were two reruptures and no other complications present. There were no significant relationships between plantar or dorsiflexion gap size and functional outcomes scores or tear location.
Gap size was not significantly related to functional outcomes. Non-operative treatment produced very good results at one year follow-up with low complication rates. These results suggest that ultrasound estimation of gap size and location may be of limited clinical value in the management of achilles tendon ruptures.
Significant variation exists amongst surgeons regarding the post operative rehabilitation protocol after surgical repair of Achilles tendon ruptures. The objective of this study was to determine the effect of early weight bearing on the postoperative recovery after surgical repair of ruptured Achilles tendons. The hypothesis was that an early weight bearing routine does not increase the rate of re-rupture or other complications, and improves the quality of life by reducing discomfort of the rehabilitation phase and allowing an earlier return to work and sport.
A prospective, randomised controlled trial of patients with Achilles tendon ruptures undergoing surgical repair was performed over a three year period concluding in April 2006. Specific inclusion and exclusion criteria were used to include one hundred and ten patients in the study at two centers involving twelve surgeons. Patients were randomised to either weight bearing or non weight bearing at the initial postoperative visit and compliance was monitored with a pressure sensor in the fixed-hinged ankle foot orthosis. Patients were assessed at six, twelve and twenty-six weeks postoperatively for 1) re-rupture rate, 2) strength of calf musculature 3) ankle range of motion, 4) complications, 5) return to sporting activities, and 6) return to work. In addition, health–related quality of life was measured using the SF-36 and AOFAS Ankle-Hindfoot Scale.
Enrollment was completed as of May 2006 and six month data is over 90% completed. We are on course for < 10% loss to follow-up. Thus far, there have been no re-ruptures in either group. Definitive data analysis can only be performed once all one hundred and ten patients have completed their six month follow up. Once data analysis is completed, comparisons of patient satisfaction, strength, range of motion, complications, return to sport and return to work will be discussed.
Early weight bearing after Achilles tendon repair did not increase the rate of re-rupture. Final data analysis will document any significant differences in the parameters measured. We believe this study will provide a definitive answer on the safety of early weight bearing after surgical repair of Achilles tendon ruptures.
The current standard of care in Calgary, Alberta for management of a ruptured Achilles tendon is surgical repair, typically performed following admission to hospital. The primary objective of this study was to compare the costs of hospital treatment and complications associated with the surgical repair of Achilles tendon ruptures between two groups of patients: Group One = patients enrolled in the randomised clinical trial (RCT) Multicentre Achilles Tendon Treatment Study (MATTS), Group Two = all other non-study patients.
This observational cohort study analyzed all patients surgically treated for Achilles tendon ruptures at Calgary area hospitals over a three-year period (October 2002–September 2005). Inclusion criteria: age eighteen to seventy years, acute rupture.
A total of two hundred and eighty-two patients met the inclusion criteria; thirty-three patients were included in Group One, two hundred and forty-nine patients in Group Two. In Group One, twenty-seven patients (82%) were treated as outpatients, five patients (15%) were ADOP-24hr, and one patient (3%) was admitted. In Group Two, twenty-seven patients (11%) were treated as outpatients, ninety-five patients (38%) were ADOP-24hr, and one hundred and twenty-seven patients (51%) were admitted. The total costs for patients treated as outpatients and requiring overnight stays in Group One were $18,408 and $7,419, respectively. In Group Two, the total cost for outpatients was $18,071 compared to $379,496 for non-study patients requiring overnight stay. If all overnight patients in each group were treated as outpatients, the total savings would be $235,545. There were no serious complications in Group One. In Group Two, complications included two cases of pulmonary embolus, and one case of compartment syndrome requiring readmission. All complications resolved.
Surgical treatment of Achilles tendon rupture can be performed safely and at less cost on an outpatient basis. Participation in this RCT has allowed us to recommend a change in the standard of care in Calgary.
The purpose of this study was to compare the clinical outcome of patients treated surgically for end stage ankle arthritis using a total ankle arthroplasty or ankle arthrodesis.
This is a multicentered prospective clinical outcome study of the surgical treatment of patients with EAA using an ankle arthrodesis (n= 117) or total ankle arthroplasty (n= 210). Clinical outcome was assessed using health related quality of life (SF36v2) and joint specific (Foot Function Index, Ankle Osteoarthritis Scale, American Orthopedic Foot and Ankle Hindfoot Scale and the AAOS Foot and Ankle Baseline Questionnaire(version 2000)) outcome scores.
Preoperatively, all patients had significant physical and psychological morbidity. All symptom and functional SF36 subscales were approximately two standard deviations below normal population scores. Approximately 25% of patients were three standard deviations below population values, indicating increased risk of mortality. There was no evidence that age or gender influenced the level of disability. There was a significant improvement in the health related quality of life and the joint specific clinical outcome scores at six and twelve months follow up but no consistent difference was noted between the two cohorts.
This is the first multicentered prospective clinical outcome study that demonstrates equal efficacy for early follow up of patients treated for EAA with total ankle arthroplasty or ankle arthrodesis.
The purpose of this study was to retrospectively review the outcomes of percutaneous flexor tenotomies of diabetic claw toes with ulcers or pending ulcers.
A retrospective chart review between January 1999 and June 2005 was performed to identify those patients that had undergone a percutaneous flexor tenotomy for diabetic claw toe deformities. Thirty-four toes in fourteen patients were identified. Twenty-four toes had ulcerations at the terminal aspect and three of these had radiographic evidence of osteomyelitis of the terminal phalange. All patients had palpable pulses and good capillary refill. A percutaneous flexor tenotomy was performed in an outpatient clinic on all toes, patients with a rigid flexor contracture at the proximal interphalangeal (PIP) joint underwent an osteoclaysis to correct a portion of the deformity.
The average follow-up was thrirteen months, all patients with ulcers healed and there were no significant complications. Those without osteomyelitis healed within an average of three weeks and those with osteomyelitis healed within an average of eight weeks.
A Percutaneous flexor tenotomy with osteoclasis of the PIP joint performed in an outpatient clinic is a safe and effective method to off-load the tip of the toe such that ulcer healing can occur. The presence of osteomyelitis is not a contraindication for this technique; however, an increased healing time can be expected.
Slipped capital femoral epiphysis (SCFE) is the most common pediatric hip disorder. The most devastating complication is development of avascular necrosis of the femoral head. In order to reduce the potential for this complication occurring following delayed contralateral SCFE, there has been consideration in the literature of prophylactic pinning of the contralateral hip. The objective of this study was to determine the cost-effectiveness of this treatment strategy.
The outcome probabilities and utilities utilised in a decision analysis of prophylactic pinning of the contralateral hip in SCFE, reported by Kocher et al, were used in this study. Costing data, reported in 2005 Canadian dollars, was obtained from our institution. Using this data, an economic evaluation was performed. The time horizon was four years, so as to follow the adolescents to skeletal maturity. Discounting was performed at 3% per year. Sensitivity analyses were conducted to determine the effect of variation of the outcome probabilities and utilities.
In all analyses, prophylactic pinning resulted in cost savings but lower utility, compared to the currently accepted strategy of observation of the contralateral hip. The results were most sensitive to an increase in the probability of a delayed contralateral SCFE to 27%. Using the base case analysis, the incremental cost-effectiveness ratio was $7856.12 per utility gained. Using the most sensitive probability of a delayed contralateral SCFE of 27%, the incremental cost-effectiveness ratio was $27,252.92 per utility gained.
The results of this study demonstrated overall cost savings with prophylactic treatment, however the utility was lower than the standard treatment of observation. For both the base case and sensitivity analysis, the incremental cost-effectiveness ratio was less than the accepted threshold of $50,000 per quality adjusted life year gained. It should be noted that the use of a four year time horizon excluded consideration of the costs related to total hip arthroplasty for the sequelae of AVN. A prospective, randomised controlled trial, with an accompanying economic evaluation, is required to definitively answer the question of the cost-effectiveness of this treatment. On the basis of this cost-effectiveness analysis, prophylactic pinning of the contralateral hip in SCFE cannot be recommended. A prospective, randomised controlled trial, with an accompanying economic evaluation, is required to definitively answer the question of the cost-effectiveness of this treatment.
The objective of this study is to report the epidemiology and results of treatment of deep infection after a reverse shoulder arthroplasty.
This is a multicenter retrospective study involving 457 reverse prostheses performed between 1992 and 2002. Fifteen patients (3%) (mean age 71 ± 9 years) presented with a deep infection. Eight were primary arthroplasties and seven were revision procedures. There were five associated peri-operative fractures and three early postoperative complications requiring surgical treatment. Infection was treated by debridement (n=4), prosthetic resection (n=10) or two-stage revision (n=1).
The infection rate was 2% (8/363) for a primary reverse arthroplasty and 7% (7/94) for revisions. The infection was diagnosed at a mean of seventeen months (range, one to fifty-seven) post-operatively, corresponding to two acute, five sub-acute and eight chronic infections. The most common pathogen was P. acnes in six cases (40%). At a mean follow-up of thirty-four ± nineteen months, there were twelve remissions (80%) and three recurrent infections. The two acute infections (one debridement and one resection) and the eight chronic infections (seven resections and one two-stage revision) were in remission. Among the five sub-acute infections, the two resections were in remission, whereas the three debridements recurred. Overall, the ten resections were in remission with seven patients disappointed and three satisfied, a mean Constant score of thirty-one ± eight points and a mean active anterior elevation of 53 ± 15°. The two-stage exchange was in remission but remained disappointed with a Constant score of twenty-seven points and an active anterior elevation of 90°.
Infection compromises the functional results of the reverse prosthesis whatever the treatment performed. Acute infections appear to be satisfactorily treated by debridement or resection. Both resection and two-stage revision can successfully treat sub-acute and chronic infection; however, debridement alone is ineffective and not recommended. There is a high rate of infection when the reverse prosthesis is used in revision arthroplasty. Prevention, by looking for such infection before surgery and by performing a two-stage procedure is recommended in the case of any uncertainty.
Avascular necrosis (AVN) of the femoral head is a devastating complication of slipped capital femoral epiphysis (SCFE). The reported prevalence of AVN following unstable SCFE has ranged between fifteen and forty-seven per cent in the literature. The explanation for this discrepancy is not clear. The inter-observer and intra-observer agreement between Orthopaedic surgeons for the radiographic diagnosis of AVN following SCFE has not been reported. It is the objective of this study to estimate these parameters between two experienced pediatric Orthopaedic surgeons for the radiographic diagnosis of AVN following SCFE.
A retrospective review of all one hundred and three cases of SCFE treated at a Canadian pediatric referral center between 1995 and 2005 was performed. Of these, eight were diagnosed, by the treating surgeon, with AVN. Each of these eight children and a random sample of fifteen of the remaining children, who were not diagnosed with AVN, were included in this study. The most recent anteroposterior and lateral radiographs were digitised and presented to two experienced pediatric orthopaedic surgeons in a blinded, random order. Each surgeon reviewed the radiographs independently and recorded which radiographs they believed to be consistent with AVN. The surgeons were told that each patient had SCFE and that some developed AVN, however neither the classification of the slip, nor the proportion who developed AVN were divulged. Each observer repeated this process two weeks after the initial review in order to determine intra-observer agreement. The kappa value was determined to assess inter-observer and intra-observer agreement.
The first observer recorded eight cases of AVN at the initial and seven cases at the second observation time. The intra-observer agreement was 0.9. The second observer recorded six cases of AVN at the initial and five cases at the second observation time. The intra-observer agreement was 0.88. The inter-observer agreement was determined at the first observation time and was 0.79.
On the basis of the results of this study, both the inter-observer and intra-observer agreement for the radiographic diagnosis of AVN following SCFE, amongst experienced pediatric Orthopaedic surgeons, was very high. It is unlikely that the reported discrepancy in prevalence of AVN following SCFE is due to a lack of inter-observer agreement, on the basis of the findings of this study. The inter-observer agreement between less experienced observers requires further study to determine if this may be the source of the variability in the reported prevalence of AVN following SCFE.
Supracondylar fractures of the humerus in children are among the most common paediatric fractures, and yet present one of the greatest technical challenges for management. Traditionally treated as surgical urgencies, recent literature calls that belief into question. The purpose of this study was to determine the influence of the elapsed time from injury to surgery of Gartland Type III supracondylar fractures on operative time and quality of reduction.
A retrospective review of all Gartland Type III supra-condylar factures treated by closed reduction and percutaneous pinning at our hospital between January 2003 and April 2006 was performed. Subjects in this consecutive series underwent a formal chart review to extract necessary data. The intra-operative fluroscopic images were utilised to assess the quality of reduction. All images were analyzed by three independent blinded reviewers on two separate occasions. Parameters measured on the AP images included: Baumann’s Angle, Humerocapitellar angle, Gordon Index, Griffet Index one and two.
Of the one hundred and forty-one charts reviewed, twenty-nine were excluded for various criteria. Of the remaining sample (N=112), sixty-one patients were treated in less than eight hours (Group one), and fifty-one treated after eighthours (Group two). There were sixty-one girls and fifty-one boys, with a mean age of six yrs. There were no cases of compartment syndrome. No subjects required conversion from closed to open reduction. The mean time from injury to surgery was six hundred and seventy minutes (min = 128, max = 3117). The mean for Group one was three hundred and forty-one minutes and one thousand and sixty-five minutes for Group two. The mean operative time was 33.29 minutes, (min=ten, max =eighty-two). The mean operative time in Group one was 33.13 minutes and 33.38 minutes in Group two. Two t-tailed t-test demonstrates no significant difference between the two groups. Radiographic analysis revealed the following means: Baumann’s angle (m = 70.26), humero-capitellar angle (m= 36.19), Gordon Index (m=33.78), Griffet Index 1 (m=0.88) and Griffet Index 2 (m=2.55). Comparison of the radiographic parameters and indices demonstrated no significant difference between the two groups.
This study demonstrates delaying surgery beyond eight hours led to no difference in operative time or quality of reduction. Previous studies have demonstrated no difference in rate of compartment syndrome, presence of complications or need for open reduction between these two groups. Our findings combined with previous retrospective studies support the need for further prospective study and support the surgeon’s clinical judgment in determining the urgency of surgical intervention in this patient population.
The promotion and practice of evidence-based medicine necessitates a critical evaluation of medical literature including the “gold standard” of randomised clinical trials. Recent studies have examined the quality of randomised clinical trials in various surgical specialties, but no study has focused on pediatric orthopedics. The purpose of this study was to assess and describe the quality of randomised clinical trials published in the last ten years in journals with high clinical impact in pediatric orthopaedics.
All of the randomised clinical trials in pediatric orthopedics published in five well-recognised journals between 1995–2005 were reviewed using the Detsky Quality Assessment Scale.
The mean percentage score on the Detsky Scale was 53% (95% CI: 46%–60%). Only seven (19%) of the articles satisfied the threshold for a satisfactory level of methodologic quality (Detsky > 75%).
The majority of randomised clinical trials in pediatric orthopedics that are published in well-recognised, peer-reviewed journals demonstrate substantial deficiencies in methodologic quality. Particular areas of weakness include inadequate rigor and reporting of randomization methods, use of inappropriate or poorly-described outcome measures, inadequate description of inclusion and exclusion criteria and inappropriate statistical analysis. Further efforts are necessary to improve the conduct and reporting of clinical trials in this field in order to avoid inadvertent misinformation of the clinical community.
As concern exists as to how much load a child should carry, we studied the gait effects of increased added mass with varied backpack styles.
Backpack loads of up to 25% increase above body weight were added to three backpack styles (double-strap, single-strap, hipster). Individuals ambulating thirty-meters, were instrumented with the WPGM tm (Walkabout Portable Gait Monitoring System). Relative power of the approximate center of mass in three dimension, gait frequency and forward and vertical asymmetries were measured. Five females (avg. age 12.4 years) and five males (avg. age 12.8 years) were compared to a group of forty-eight normal age-matched controls. Data was analyzed with the GaitView tm (Innomed) and Excel tm (Microsoft) programs.
Overall, with 25% increased mass above body weight there was an 8% reduction in velocity (r2 0.9641). Velocity reduction occured with decreased step length (r2 0.9924). The hipster showed significant slowing with no difference between one and two strap models. Forward asymmetry increased 20% and vertical asymmetry increased 10% for all backpack styles. The two-strap gave minimal asymmetry with the one strap and hipster showing significant differences. Relative power decreased 20% and 15% in the vertical and forward dimension and increased 15% horizontally.
Significant difference of approximate center of mass measurements for boys and girls with increasing backpack weight occurred between 10–15% increased loads. With loads of up to 25% greater than body weight, differences are seen with gait velocity slowing, increasing asymmetry, and greater horizontal power. The two-strap backpack is superior in its effect of minimizing asymmetry and velocity impacts.
Metacarpophalangeal (MP) arthroplasty restores function, corrects deformity and reduces pain in patients with rheumatoid arthritis (RA). In a randomised controlled trial of MP hand reconstruction, we investigated RA patient motivations and expectations and whether self-reported patient satisfaction with appearance, function and pain correlated with objective and subjective outcome measures.
From forty patients (one hundred and sixty joints), randomised for an MP arthroplasty trial, we collected preoperative and postoperative objective measures (range of motion (ROM), ulnar drift, JAMAR grip strength), subjective measures (Michigan Hand Questionnaire (MHQ), Sollerman Hand Function test), pre-operative patient-reported motivations and expectations of surgery (appearance, function, pain), and postoperative patient-reported improvement and satisfaction with surgery (appearance, function, pain, overall). Spearman correlations determined associations between patient satisfaction and specific outcome measures.
Mean age was 60.3 years, mean disease duration at time of surgery 22.9 years, mean follow-up time 386.4 days, and 87.5% of patients were female. Seven of forty patients (17.5%) rated improved function as the single biggest motivator for surgery, one (2.5%) rated pain, the remainder (80%) rated two or more motivators equally high. Function was rated as the most important or one of the most important motivators for surgery by 92.5% of patients, pain by 67.5% and appearance by 47.5%. Several MHQ subscores (function, work, ADL) were moderately correlated (|rho|=0.67, 0.52, 0.54, respectively), and the Sollerman Score was weakly correlated (|rho|=0.39) with self-reported satisfaction with function, but ROM and grip strength were not (|rho||< 0.25). Self-reported satisfaction scores for appearance, pain and overall were moderately correlated with analogous MHQ subscores (|rho|=0.78, 0.65, 0.71, respectively).
Patient expectations of MCP arthroplasty were uniformly high. The greatest motivation for surgery was functional improvement. Pain was highly ranked, but nearly half of the patients rated hand appearance as one of the highest co-ranked motivators. Patient satisfaction correlated poorly with traditional outcome measures (ROM, grip strength) and moderately with subjective outcome measures (MHQ). Aesthetic appearance is probably underrated as a motivator for surgery and determinant of satisfaction.
The purpose of this study is to catalogue humeral problems with reverse total shoulder arthroplasty and define their influence on outcome.
A multicenter retrospective review of 399 reverse humeral arthroplasties implanted between January 1994 and April 2003, yielded seventy-nine patients with humeral problems. We define a clinical humeral problem as an event that alters the expected rehab or postoperative course. Perioperative problems are fractures within the stem zone while postoperative problems involve fractures distal to the stem, prosthetic disassembly and subsidence. Radiologic problems include humeral loosening and radiolucencies of greater than 2 mm that have not had a clinical impact. All radiographs were available and reviewed by three orthopaedic surgeons. Objective results were rated according to the Constant score; active forward flexion and external rotation were recorded; and subjective outcome was noted.
We identified twenty-six intra-operative fractures and eleven postoperative fractures. There were four cases of disassembly, three cases of subsidence, and fifteen cases of radiographic loosening. At a mean follow-up of forty-seven months, average active elevation was 111.3 degrees, external rotation was 7.0 degrees, and absolute Constant score improved from 21.9 to 50.1 points. Seventy-one percent of the patients were satisfied or very satisfied. Intra-operative humeral fractures were associated with poor final Constant score (42.3), poor range of motion and increased shoulder pain (p=0.001 for all items). Constant score for those revision patients who experienced a fracture was lower by 9.6 points (p=0.0347) than those patients who underwent a reverse prosthesis for revision surgery without a fracture. Constant score for those patients with a postoperative fracture averaged 47.2 (range, 8–70). A re-operation was performed in seven of the cases (9%).
Intra-operative humeral fractures occur commonly when a reverse prosthesis is indicated for revision; humerotomy is not protective, however, and is not recommended for all humeral revisions. Fractures, either intraoperative or post-operative, result in lower Constant scores. Any patient who received an intervention for a humeral problem yielded a lower constant score. While postoperative Constant scores improved in all categories, they were lower than those patients who did not sustain a humeral complication.
The purpose was to evaluate the results of reverse shoulder arthroplasty (RSA) in proximal humerus fracture sequelae (FS).
Multicenter retrospective series of forty-five consecutive patients operated between 1995 and 2003. Types of FS included: cephalic collapse and necrosis (n=8), chronic locked dislocation (n=5), surgical neck nonunion (n=7), severe malunion (twenty), and isolated greater tuberosity malunion (n=3). Twenty-six patients had surgical treatment of the initial fracture and seventeen had non-surgical treatment; thirty-three Delta and ten Aequalis reverse prosthesis were implanted. Mean age at surgery was seventy-three years (range, fifty-seven to eighty-six). Forty-three patients were available for clinical and radiologic evaluation with a mean follow-up of thirty-nine months (range, twenty-four to ninety-five).
Nine re-operations (21%) and ten complications (23%) were encountered, including four infections (leading to two resection-arthroplasties), two instabilities, one glenoid fracture (converted to hemiarthroplasty) and one axillary nerve palsy. Thirty-six patients (83%) were satisfied or very satisfied with their result. The adjusted Constant score improved from 29% preoperatively to 75% postoperatively (p< 0.0001), the Constant score for pain from fou to twelve points (p< 0.0001), and active anterior elevation from 59° to 114° (p< 0.0001). Active rotations were limited. A positive postoperative hornblower test negatively influenced Constant score (forty-two points compared to 61.5 points, p=0.004) and external rotation (−6° compared to 15°, p=0.004). The lowest functional results were observed in surgical neck nonunions (with five complications) and isolated greater tuberosity malunions. In type four fracture sequelae, patients who had an osteotomy or resection of the GT (n=9) had better forward flexion (140° compared to 110°, p=0.026) and better Constant score (sixty-three points compared to forty-six points, p=0.07).
RSA can be a surgical option in elderly patients with FS, specifically for those with severe malunion (type four fracture sequelae) where hemiarthroplasty gives poor results. By contrast, surgical neck nonunions (type three) and isolated greater tuberosity malunions are at risk for low functional results. The surgical technique and the remaining cuff muscles (teres minor) are important prognostic factors. Functional results are lower and complications/reoperations rates are higher than those reported for RSA in cuff tear arthritis.
This prospective controlled clinical trial compares the outcomes of metacarpophalangeal (MCP) arthroplasty in rheumatoid arthritis patients using the Swanson (S) and NeuFlex (N) MCP implants.
Forty hands (thirty-seven patients) were randomised and evaluated preoperatively and at one year following MCP arthroplasty in digits two to five for range of motion (ROM; active and passive extension and flexion), ulnar drift and grip strength.
Both implants restored extension and corrected flexion deformities. There was no significant difference in extension of all digits (summed) between the NeuFlex and Swanson implants (N: −20.8°; S: −13.8°; p=0.29). The NeuFlex implant, which is pre-flexed at 30°, preserved more flexion at the MCP joint than the Swanson implant in all digits (summed) (N:74.5°; S:55.8°; p=0.005), with the greatest difference observed in the fifth digit (N:69.6°; S:48.7°; p=0.009). The total arc of motion improved in all digits, with no significant differences between the Neu-Flex and Swanson groups in the second through fourth digits (N:53.8°; S:43.8°; p=0.154); a significantly greater improvement was observed in the NeuFlex group for the fifth digit (N:53.3°; S:42.5°; p=0.028). Both implants corrected ulnar drift deformity, while neither led to loss of grip strength.
Hand function as measured by Sollerman score and Michigan Hand Questionnaire (MHQ) improved significantly in both groups (p=0.0119, p< 0.0001, respectively) with no significant difference between the Swanson and NeuFlex implants, except for MHQ function, aesthetics, and overall scores, which demonstrated superiority of the Swanson.
Overall, there was a significant improvement in the range of motion, deformity and grip strength following MCP arthroplasty for the full patient group. While both implants restored similar amounts of extension, the NeuFlex implant maintained greater flexion and total range of motion, with the greatest difference in the fifth digit. The Swanson implant had better MHQ function and aesthetics subscores.
Type II SLAP lesions account for 22–55% of all SLAP lesions and are described as detachment of the superior labrum along with the biceps anchor from the superior glenoid rim. This detachment may be associated with glenohumeral joint instability. The majority of SLAP lesions are associated with other pathologies such as rotator cuff tears, Bankart and other instability lesions. The purpose of this study was to evaluate the effectiveness of arthroscopic repair of type II SLAP lesions, two years following arthroscopic repair with suture anchors.
Data on thirty-eight consecutive patients (thirty-four males, four females, mean age: forty-five years, range, twenty-two to seventy years) were used for analysis. Outcome measures were the American Shoulder and Elbow Surgeons (ASES) assessment form and the Constant-Murley score. Thirteen patients had work-related injuries. Specific tests for SLAP lesion (i.e. New pain provocation test, O’Brien test, Yergason’s Test) were conducted pre-operatively.
Twenty-three patients had surgery on the right side. The O’Brien test was positive in 51% of the patients. The minimum follow up period was twenty-four months. Five patients had isolated SLAP type II lesion. Thirty-three had associated pathologies. Ten patients had rotator cuff repair. Twelve patients required acromioplasty and one patient underwent the long head of biceps tenodesis. Three patients had associated Bankart lesions. All patients showed significant improvement in ASES scores (p< 0.0001). However, Patients with work-related injuries did not show a significant improvement in Constant-Murley scores (p=0.20). Associated pathologies did not affect level of disability or subjective scores post-operatively. Strength did not change to a statistically significant level following SLAP repairs.
Arthroscopic SLAP repair provides significant improvement in subjective scores of the ASES. Patients with work-related injuries demonstrate a different pattern of recovery.
The traditionally accepted etiology of Scapholunate Advanced Collapse (SLAC) requires traumatic rupture of the scapholunate (SL) ligament which leads to abnormal wrist kinematics and thereafter severe localised degenerative arthritis of the wrist. The purpose of this prospective blinded kinematic analysis was to demonstrate that SLAC wrist also exists in the absence of trauma, and that abnormal carpal bone kinematics (specifically, decreased lunate flexion) is the initiating factor.
Patients with SLAC and no history of upper extremity trauma were compared with an age matched control group. All patients completed a questionnaire, personal interview, and a physical examination. A specialised flexion / extension radiographic jig was designed to control for the magnitude of force and position of the wrist in all planes.
A total of thirty-five subjects (sixty-nine wrists) were retained for the study, including thirty-three non-traumatic SLAC wrists and thirty-six control wrists. The non-traumatic SLAC group had significantly different radiographic kinematic analysis compared to the control group: increased Watson Stage (2 v 0), SL gap (3.4 v 1.8mm), revised carpal height ratio (rCHR) (77 v 68), SL angle in flexion (forty-one v twenty-eight degrees), and decreased radiolunate (RL) joint flexion (nine v twenty-seven degrees). Most importantly flexion of the asymptomatic non-degenerative wrist of the non-traumatic SLAC group was distributed 70% through the lunocapitate (LC) joint and only 30% through the RL joint (p< 0.05). Conversely, flexion was more evenly distributed in the control group (48% LC and 52% RL). Non-traumatic or developmental SLAC does exist. SLAC can thus be classified into non-traumatic (developmental) and traumatic types.
Non-traumatic SLAC begins with abnormal wrist kinematics. Over time restricted lunate flexion and normal scaphoid flexion leads to increased SL angles and eventual attrition of the SL ligament and predisposes patients to SLAC despite having no history of trauma.
Health utilities indicate the value of a given health state. They are essential components of decision analyses, and economic evaluations. In the area of total shoulder arthroplasty (TSA) we were unable to find literature estimating changes in utilities or the effect of method of obtaining utilities. The purpose of this pilot study was to describe the trajectory of utility scores before and after TSA using three approaches: the EQ-5D and the Health Utilities Index (HUI2 and HUI3) self-report format.
Twenty-four patients undergoing TSA at two teaching hospitals (Boston and Toronto) were assessed twice preoperatively, as well as at four and twelve weeks follow-up by self report mailed survey. At each survey all three utility estimates were obtained. Demographic and functional status was also gathered. The EQ-5D is a five item questionnaire which scores into a profile to which utility weights obtained from the developers were applied. The HUI self-report is a fifteen item scale obtaining a score on eight domains. A multiplicative formula is used to assign utility weights to these responses. Descriptive analysis of the sample, baseline characteristics and change in utility were completed. Intra-class correlation coefficients were used to calculate test-retest reliability between the two preoperative visits. Standardised response means (SRM) (mean change/SD of change) and relative efficiency (RE=ratio of SRM2) were calculated. Individual trajectories of change were graphed and examined for trends.
Twenty-four patients participated with average age of sixty-seven years, 58% were female and experienced large improvements in disability and pain (mean change DASH = 18.9/100, SPADI Pain = 30.3/100). Utility scores had low to moderate correlations with each other (0.26–0.68). Mean baseline scores were low (EQ5D=0.44, HUI2=0.68, HUI3 = 0.50). The average change in utility is shown in the following table along with effect size estimations and test-retest reliability.
Patients experience clinically important and statistically significant changes in their utility values even in the early stages of recovery after TSA (three months). The HUI3 and EQ-5D were most responsive to changes experienced in this sample.
To prospectively evaluate patient outcome in terms of stability, function and satisfaction following an arthroscopic anterior Bankart repair in order to identify patient characteristics, surgical technique or instrumentation linked to poor outcomes. These findings can then be used to refine selection criteria such that patient benefit from the shoulder instability repair is maximised.
Between April 2002 and June 2004 thirty-seven arthroscopic anterior Bankart lesion repairs were performed by a single orthopaedic surgeon. Data on concomitant shoulder pathology, surgical technique utilised and instrumentation used was recorded for each patient. Reoccurrence rate, patient satisfaction and range of motion were evaluated pre-operatively, and then six weeks, three months, six months, twelve months and twenty-four months post-operatively.
Four of thirty-seven patients (10.8%) experienced at least one post-operative reoccurrence defined as a subluxation or dislocation. There was a statistically significant association between the presence of an inverted pear-shaped glenoid and increased incidence of reoccurrence (p < 0.05). Patients’ satisfaction with their shoulders increased significantly from 43% pre-operatively to 71% at the two-year follow-up, as measured by the Western Ontario Shoulder Instability (WOSI) scale. There were no significant differences in range of motion between the patients’ surgically repaired and unaffected shoulders.
An arthroscopic repair of an anterior Bankart lesion can yield good-to-excellent results for the majority of patients with respect to stability, function and satisfaction. The presence an inverted pear-shaped glenoid is mostly strongly correlated with an increased incidence of reoccurrence. Patients should be screened pre-operatively to identify this bony abnormality such that it can be addressed appropriately during surgery.
Various studies report a correlation between the severity of the primary displacement, carpal malalignment & an expectant loss of reduction over a given time period when treating distal radius fractures with cast immobilization. Recently, studies have attempted to classify carpal malalignments associated with displaced distal radial fractures based on Effective radio-lunate flexion (ERLF) into: midcarpal with ERLF < 250 and radiocarpal malalignment with ERLF > 250. The aim of this study was to assess the frequency of carpal instability as a concomitant lesion to fractures of the distal radius, delineate further various factors including associated carpal malalignment based on ERLF that are predictive of instability based on a timeline of early (one week) and late failure (six weeks) in an attempt to predict the final radiological outcome accurately
Radiographic alignment parameters were compared before and after reduction using paired t-tests and then also analysed in a multiple logistic regression analysis.
Early failure group: Regression analysis showed high correlation between the severity of axial shortening before reduction and at one week. Age, gender, presence of dorsal comminution, ulnar styloid fracture, initial dorsal angulation and flattening of radial angle were unreliable in predicting early failure at one week. Late failure group: We found radial shortening, dorsal tilt, presence of dorsal comminution & ERLF > 25 to be significant predictors of adverse radiological outcome at six weeks. Age, Gender, flattening of radial angle, ulnar styloid fracture as factors for secondary displacement when analyzed independently or in combination were not found to be significant predictors of late failure. The incidence of failure was significantly correlated to radiocarpal malalignment pattern in post reduction radiographs (ERLF> 25) and both at one and six weeks when analysed independently or in combination (p< 0.01)
Our study reaffirms the need to attention to initial fracture characteristics and highlights the importance of radiocarpal instability pattern on post reduction radiographs as a predictor of late instability. This would allow the surgeon to inform the patient of chance of success with closed treatment and alternative treatment options.
Controversy exists surrounding best practice for antibiotic prophylaxis in TJR. Practicing orthopedic surgeons performing TJR in Canada were surveyed to inform regarding the most common antibiotic prophylaxis practice.
Cross-sectional survey of five hundred and ninety practicing Canadian orthopaedic surgeons was conducted. Three orthopaedic surgeons, and one infectious disease specialist established face and content validity of the survey. The survey was mailed to surgeons, and re-mailed to non-responders at twelve-weeks. Survey included questions pertaining to prophylaxis indications, antibiotic choice, dosing, route and timing of administration in the primary and revision setting, as well as postoperative wound drainage investigation and management.
Response rate after two mail-outs was 410/590 (69.5%). 96.6% indicated routine use of systemic prophylactic antibiotics for uncomplicated primary TJR. Cefazolin was most commonly prescribed (97.3 %), with 1gm Cefazolin the most common dosage (70.2%). Vancomycin was prescribed 26% of the time as first line. 48.5% administer the antibiotic in the operating suite, and 90% administer within < sixty minutes prior to skin incision. 47.8% routinely use antibiotics in acrylic cement, and 50% use it in a commercially prepared form. Postoperative prophylaxis duration varied widely with 42% preferring twenty-four hours. 33% routinely culture serous wound drainage within one-week postoperative in the absence of redness or fever. 19.8% prescribe antibiotics if wound drainage persists beyond hospital stay. 15.6% would conduct intraoperative wound exploration if drainage persists beyond postoperative day four. 63.9% stated they routinely withhold antibiotics until they have obtained a deep tissue culture specimen in revision TJR. 74% use the same antibiotic prophylaxis regimen for both primary and revision procedures. Of responding surgeons, 47/410 (11.8%) were categorised as high volume performing > two hundred TJR’s per year, and 40/410 (9.8%) were categorised as low volume performing < twenty-five per year. Comparative results to be discussed.
Opinions vary widely amongst surgeons in Canada, illustrating the controversy in what constitutes ‘best practice’. Despite available published data, a large proportion of Canadian surgeons may fall short in meeting optimal standards of care in some domains such as the dose prescribed and timing of administration. This survey also illustrates the lack of available information to guide current management of postoperative wound drainage in the face of shorter patient hospital stays. Much work is needed in this area to determine risks and benefits of these costly tests and interventions in treating arthroplasty patients.
To prospectively evaluate the accuracy as well as patient outcome of computer-assisted total knee replacement in a multi-centric randomised study.
Two hundred and ninety-five patients in six European centers were randomised between two groups: One hundred and forty-seven in the conventional surgery group and one hundred and forty-eight in the computer assisted surgery. Radiological as well as clinical data (SF-36 and KSS scores) were collected preoperatively as well as six weeks and six months postoperatively. A multilevel mixed-effects linear regression for nested variable with random-effects was used to estimate the effect of the independent variable (type of surgery: conventional surgery vs computer assisted surgery) on each of the dependent variables at six weeks and six months post-operatively.
Mechanical axis was statistically better in the navigation group at six weeks (p=0,01) and six months (p=0,04). Similar results are found for the femoral component at six months (p=0,001). At six months, there were statistically greater improvements in the following SF-36 scales for the computer assisted group: bodily pain (p=0,03), role emotional (p=0,03), mental health (p< 0,001), physical health dimension (p=0,01), mental health dimension (p=0,005) and global SF36 score (p=0,002). While a difference in operating time was noted (p< 10-5), the blood losses where similar for both groups (p=0.8).
Computer assisted surgery improves the accuracy in total knee arthroplasty, especially for the mechanical axis and the femoral component orientation. These improvements result in better quality of life for the patient at six months postoperatively. Level of Evidence: I – High-quality randomised controlled trial with statistically significant difference.
Image guided navigation systems for total knee replacement surgery (TKR) are gaining popularity in an effort to improve both alignment and functional outcome. This trial was undertaken to compare one year functional outcome and radiological alignment of TKRs inserted with and without an image guided navigation system.
Patients were randomised to undergo surgery using either an image guided navigation system or traditional instrumentation. Pre and post-operative Knee Society (KSS), WOMAC and SF-36 scores were collected. Postoperatively, limb and implant alignment & rotation were assessed using both full-length films and CT scans.
One hundred and twenty-three patients (one hundred and forty-five knees) were enrolled: eighty-one females, forty-two males, mean age sixty-seven years. Age, gender and pre-operative range of motion, KSS WOMAC and SF-36 scores did not differ between the groups. While there was no statistically significant difference in postoperative KSS, WOMAC and seven of eight SF-36 subscales, the navigated group demonstrated better post-operative SF-36 General Health Scores. Mean postoperative flexion in all patients was 115°, and did not differ between groups. Mean post-operative leg alignment demonstrated more varus in the navigated group (2.1°) versus the non-navigated group (0.9°, p=0.02), however there was a trend towards a smaller standard deviation in the navigated group. Rotational alignment of the femoral component relative to the femur, tibial component relative to the tibia, and tibial component relative to the femoral component were not statistically different between groups; however, there were larger standard deviations of these measures in the non-navigated group. Pre-operative alignment appeared to affect tibial component placement; varus knees had a mean of 3° of tibial component internal rotation while valgus knees had a mean of 12° external rotation.
Imaged guided navigation systems appear to reduce the variability in TKR component placement and limb alignment. However, this may not necessarily translate into better mean limb alignment or early functional outcome.
Effectiveness of Surgery for Acromio-clavicular joint dislocation is a controversy. Multitude of highly variable techniques and equally variable results make the choice of surgical procedure difficult. Open Reduction and Internal Fixation (ORIF) (Intra-articular) with Tension Band Wiring(TBW)and K-wire fixation and Modified Weaver Dunn(WD) Procedure (extra-articular) were the two procedures analysed in this study.
Retrospective review of case notes of patients admitted for ACJ stabilization procedure. For each patient pro-forma filled in Conducted Telephone review of the cases and obtained the long term functional out come using Oxford shoulder Scoring System. Compared the functional outcome of various surgical procedures for ACJ Stabilization with the standards
We had eighteen cases of ACJ stabilization over a period of ten years. Eleven WD reconstruction and seven ORIF with TBW. Mean age of the group: thirty-one years. 70% were males. Mechanism of injury was fall in 60%. 77% had Grade three Rockwood ACJ dislocation and rest were grade four. Reason for operative management in majority of them were pain and weakness of shoulder. Most of them had the surgery done between one month and two years from the date of injury. Four out of seven ORIFs had post op complications like wire breakage, impingement and pain. Only two out of eleven Weaver Dunn had pain post operatively. All the four ORIFs which developed post op complications had the metal work removed. Long term functional results by Oxford shoulder score has shown good result in all the patients who had telephone review irrespective of the type of procedure.
WD Reconstruction has got less post operative complications and better short term functional out come compared to ORIF. Four out of seven ORIF patients needed a second surgery for metal work removal. WD Reconstruction, being a soft tissue procedure using biodegradable materials, never required a second surgery. Long term functional results were same for both types of procedures We recommend modified WD for the following reasons: 1. Better short term functional outcome and hence faster recovery. 2. No need for a second surgery. Hence they imposes less financial burden for the hospital as well as the patient Summary: Choice of surgical procedure for Grade three and above Acromio-clavicular joint dislocation is controversial. The extra-articular soft tissue procedures have a faster recovery but long term functional results are similar to that of intra-articular ORIF procedures.
We compared self-reported pain and function, complications and revision rates, and radiographic outcomes of hydroxylapatite(HA) or cemented tibial fixation in the first five years following primary total knee arthroplasty. This was a randomised clinical trial of eighty-one patients
Prospective, randomised clinical trial. Patients less than seventy years of age with non-inflammatory knee arthritis. Eighty-one patients were randomised at the time of surgery to receive HA or cemented tibial fixation. Subjects were evaluated preoperatively, six months, one and five years postoperatively by a physical therapist who was blinded to group allocation. X-rays were evaluated by an experienced arthroplasty surgeon who did not perform any of the surgeries. Self-reported pain and function, the primary outcomes, were measured by the Western Ontario McMaster (WOMAC) Osteoarthritis Index and the RAND 36-item Health Services Inventory (RAND-36). Complications and revision rates were determined through hospital record review and at each patient evaluation. The Knee Society Radiological Score was used to evaluate plain radiographs at each assessment.
There was slightly more pain in HA group at six months as measured by both the WOMAC and RAND-36, a difference that disappeared by the one-year assessment. There were no differences in function, radiographic findings or complications at any time. Finally, no subjects required revision of the tibial prosthesis during the study.
Overall, no significant differences were seen between groups. The initial difference in self-reported pain disappeared by twelve-months postoperatively. At five-years postoperatively, there is no advantage to HA tibial fixation over cemented tibial fixation.
The purpose of this study is to compare the long-term clinical results of two total knee replacement designs (the SAL-II mobile-bearing implant and the fixed-bearing Genesis I implant) to see if there are any advantages to the use of a mobile-bearing design in the long-term.
One hundred and ninety-two patients with an age range between twenty-five to ninety who were implanted with either an SAL-II (Group A) or GEN I (Group B) at London Health Sciences Center, University of Western Ontario, were included in the study. Patients with a diagnosis of inflammatory arthritis or with previous high tibial osteotomy were excluded from the study. Demographic data as well as functional outcome measures such as range of motion, knee alignment, specific measures of activities with daily tasks, and composite knee scores such as the Knee Society Clinical Score and Functional Score were collected from the patients’ medical charts and compared. Data was analyzed using SPSS V14.0 statistical software.
Group A included eighty-three mobile-bearing platform arthroplasties in seventy-seven patients. There were forty-one males and thirty-six females. The average age of the patients at the time of surgery was 67.7. Average follow up time was 10.56 years from the date of surgery. Eleven patients were excluded from the study, ten due to previous HTO surgery and one due to rheumatoid arthritis. At latest follow-up, ten patients required revision, and fifteen patients died. Group B included one hundred and thirty-one fixed-bearing knee arthroplasties in one hundred and fourteen patients. There were forty-one males and seventy-three females. The average age of the patients at the time of surgery was 65.8. Average follow up time was 9.58 years from the date of surgery. Twenty five patients were excluded from the study, twenty three patients due to previous HTO surgery and two patients due to rheumatoid arthritis. At latest follow-up, thirteen patients required revision, and twelve patients had died. Include Results and p-values at this stage. No statistically significant difference was found between the groups, either for the knee score (p=0.536), the function score (p=0.115), the range of movement (p=0.718) and number of revisions. Ten years survivorship for mobile bearing group was significantly lower than the fixed bearing group (p=0.005) although this equalised at fifteen years.
This study is the first long-term study that compares the results of the mobile-bearing and fixed bearing designs performed by the same surgeons in the same period of time. The results of this study show no difference in these two designs at a mean of ten years follow-up although fixed bearing design demonstrated better overall ten years survivorship. This difference can be related to the earlier mobile bearing revisions due to aseptic loosening and instability. Mobile bearing designs have yet to prove their theoretical advantage in clinical practice.
The purposes of this study were to determine the effect of severity, wait times and patient perspective on outcomes and to create an eivdence-based prioritization tool.
Patients who received a primary hip or knee replacement were followed forward from decision date for surgery to one-year follow-up (N = 4437) and outcomes assessed according to baseline severity. At decision date for surgery, patient baseline severity was captured using the WOMAC disability questionnaire. Twelve to eighteen months after surgery, a questionnaire (WOMAC, satisfaction) was sent to patients to compare pre- and post-operative data.
The chance of a good outcome from TJR surgery gets worse as wait times get longer. Baseline severity affects outcome more than wait times. Patients with a baseline WOMAC less then 30/100 should have surgery within three months (20% patients) If surgery cannot be done within three months, then three priority levels are recommended: Priority I – One month maximum: catastrophic hip or knee joint conditions – complications that are an immediate threat to independence. Priority II – three months maximum: extreme pain and disability because of hip or knee joint condition that will be a threat to role and independence within three months (baseline WOMAC less than or equal to 30/100). Priority III – six months maximum: severe pain or disability because of hip or knee joint condition, but role and independence not threatened (baseline WOMAC over 30/100).
The priority levels and wait time thresholds recommended in this study are the result of an analysis of pre-operative severity scores, the length of the wait and post-operative outcomes and are consistent with data from other sources.
The purpose of this study was to assess the accuracy of clinical assessment compared to imageless computer navigation in determining the amount of fixed flexion during knee arthroplasty.
In fourteen cadaver knees, a medial para-patella approach was performed and the navigation anatomy registration process performed. The knees were held in various degrees of flexion with two crossed pins. The degree of flexion was first recorded on the computer and then on lateral radiographs. The cadaver knees were draped as for a knee arthroplasty and nine examiners (three arthroplasty surgeons, three fellows, and three residents) were asked to clinically assess the amount of fixed flexion. Three examiners repeated the process one week later.
The mean error from the radiograph in the navigation group was 2.18 degrees (95%CI 2.18+/−0.917) compared to 5.57 degrees (CI 5.57+/− 0.715) in the observer group. The navigation was more consistent with a range of error of only 5.5 degrees (standard deviation 1.59). The observers had a range of error of 18.5 degrees (S.D. = 4.06). When analysing the observers’ error with respect to flexion (+) and extension (−), they tended to under-estimate the amount of knee flexion (median error=−4) whereas the navigation was more evenly distributed (median error=0). The highest correlation was found between navigation and the radiograph r=0.96. The highest observer correlation with the radiograph was a consultant surgeon (r=0.91) and the worst was from a resident (r=0.74). The intra-class correlation coefficient was 0.88 for the three surgeons who repeated the measurements; their mean error was 3.5 degrees with a range of fifteen degrees.
The use of computer navigation appears to be more accurate in assessing the degree of knee flexion, with a reduced range of error when compared to clinical assessment. It is therefore less likely to leave the patient with residual fixed flexion after knee arthroplasty.
The association between obesity and sleep apnea syndrome (SAS) is well known, as is the fact that TJR patients are often obese. Based on review of 5819 primary TJR patients at our institution, 53% of patients presenting for TJR were obese (mean BMI 31), and of those obese patients 61.3% were female. The potential impact of SAS, diagnosed and undiagnosed, on TJR outcomes has not been well described. In the literature it has been suggested that such patients may be at increased risk of prolonged hospital length of stay (LOS), increased risk of postoperative MI, and risk of postoperative respiratory compromise requiring unplanned transfer to a special care unit (SCU). At our institution, unless deemed required for preoperatively identified co-morbidities, all TJR patients are managed acutely on an orthopaedic ward with no formal step down unit available for enhanced monitoring, even when receiving PCA or epidural for postoperative pain control.
We undertook a prospective non-randomised survey of 1927 primary TJR patients over a fifteen-month period to screen for a preoperative diagnosis of SAS, or symptoms suggestive of SAS using the self-report Epworth Sleep Apnea Questionnaire. In addition, we evaluated impact of SAS on LOS, risk of postoperative MI, risk of postoperative respiratory compromise and unplanned transfer to SCU.
Of our sample, 88/1927 patients (4.6%) had a confirmed preoperative diagnosis of SAS. An additional 74/1927 patients (3.8%) had 3/3 symptoms suggestive of undiagnosed SAS. SAS patients were younger; mean sixty-six years, p=0.005, and predominantly male; 58%, p< 0.0001, as compared to non-SAS patients comprised of 60% females and mean age sixty-nine years. Mean BMI was higher in the SAS group; 32.3 versus 30, p< 0.0001. There was no correlation between SAS and risk of postoperative MI, LOS (mean 5.2 days, both groups), nor unplanned SCU admission.
Despite concerns expressed in the literature, we found that SAS, both diagnosed and suspected, was not associated with prolonged LOS, increased risk of postoperative MI, postoperative respiratory compromise, or unplanned postoperative transfer to a SCU.
Revision surgery is an important outcome of hip and knee arthroplasty among patients with osteoarthritis (OA). The objective of this study was to determine the risk of revision over time in a large, geographically defined population in North America, and to assess the effects of age, sex, and socioeconomic status (SES) on knee and hip revision rates in this population.
We used data on admissions to all acute care hospitals in British Columbia (BC), Canada (population of four million people) from 1986 until 2004 (eighteen years of follow-up). Primary knee and hip replacement surgery for OA and revision procedures were identified using diagnostic (ICD-9, ICD-10) codes and surgical procedure codes. We excluded cases admitted due to injury or neoplasm. SES was assigned based on residential address linked to census data at the level of enumeration area (ecological variable), and analyzed according to quintiles or deciles of the distribution. In the analysis, we used Kaplan-Meier survival curves to describe the risk of first revision following first primary replacement surgery over time and parametric (Weibull) survival regression models to analyze the effects of joint (hip vs. knee) age, sex, and SES on revision rates. Death, emigration, and another primary joint replacement were treated as censoring events.
Between 1986 and 2004, we observed 24,169 first primary hip replacements and 22,875 first primary knee replacements. In these patients, there were 1,313 hip revisions and 914 knee revisions following a primary replacement. The risk of revision at five, ten and fifteen years after primary replacement according to joint and sex were identified The overall risks were 10.1% for the hip and 8.7% for the knee at ten years, and 15.5% and 14.7%, respectively, at fifteen years. Risk of revision (%) following first primary joint replacement surgery Hip Knee Years Men Women Men Women 5 5.0 3.9 4.6 3.8 10 11.0 9.4 9.7 8.0 15 17.8 14.1 18.5 12.4 In a multivariate survival regression model including joint, age, sex, and SES, only age and sex were significantly associated with revisions. The hazard ratio was 1.2 for men compared with women (p< 0.0001). Revision rates were higher in younger persons, with hazard ratios increasing from 1.7 for age 70–79 (p< 0.0001) to 3.9 for age < 49 (p< 0.0001) compared with age 80+. After adjusting for age and sex, SES was not significantly associated with revision risk following primary hip or knee replacement surgery in this population (p=0.75).
This is one of the largest and longest cohort studies in North America to look at the epidemiology of revision procedures following hip and knee replacement for OA. Higher rates in men and in younger persons are consistent with previous reports. The lack of association between revision risk and SES in BC is an important finding given current concerns about socioeconomic disparities in access to and outcomes of treatment for OA.
Prior to TJR, clinical cardiovascular risk assessment is typically limited by severe exercise restrictions. Noninvasive pharmacological cardiovascular stress tests may predict major perioperative cardiovascular events in patients undergoing orthopaedic surgery. We undertook a pilot study to inform the feasibility of a large prospective cohort study.
Patients were eligible if they were aged > forty-five, undergoing elective TJR, and had known atherosclerotic disease or risk factors for atherosclerotic disease. We recruited patients at the Hamilton Health Sciences, Henderson Hospital. Prior to surgery patients underwent dipyridamole stress perfusion imaging and dobutamine stress echocardiography. For both tests the interpreters evaluated seventeen myocardial segments and were blinded to information about patients’ clinical risk factors. The attending surgeons and research personnel following patients after surgery were blinded to results of the noninvasive pharmacological cardiovascular stress tests. All patients had an ECG performed and troponin T drawn six to twelve hours postoperatively and on the first, second and third days after surgery.
Starting in November 2005 we recruited thirty patients over six months; seventeen (57%) patients were male, twenty-one (70%) underwent TKA, and nine (30%) underwent THA. The length of surgery was seventy-two (SD 38) minutes and the length of hospital stay was five (SD 3) days. We successfully followed all patients to thirty days after surgery. Three patients (10%; 95% CI, 3–26%) suffered a perioperative myocardial infarction. Twenty nine patients underwent dipyridamole stress perfusion imaging prior to surgery; a reversible defect involving 30–50% of the myocardium increased the likelihood of a perioperative myocardial infarction (likelihood ratio [LR] 4.0; 95% CI, 1.2–13.3). Twenty-six patients underwent dobutamine stress echo-cardiography; a reversible defect increased the likelihood of a perioperative myocardial infarction (LR 4.0; 95% CI, 0.7–22.9).
This pilot study demonstrates the need for, and feasibility of, a large prospective cohort study to determine if preoperative noninvasive pharmacological cardiovascular stress testing has additional predictive value, beyond clinical variables, for the occurrence of myocardial infarction in patients undergoing major hip and knee surgery.
The purpose of this study was to assess the influence of patient factors on six to eleven year TKR outcomes.
Three hundred and sixty-five consecutive patients (436 Genesis II TKR’s) were prospectively analyzed according to gender, diagnosis, body mass index, pre-operative deformity, pre-operative range of motion and implant type.
The Kaplan-Meier survivorship for the TKR patients was 98% ±.8% at nine years. Large and significant improvement in pre-operative health related quality of life (HRQL) outcomes (KSCR, WOMAC and SF-12) were noted Female patients demonstrated significantly worse pre-operative and post-operative KSCR, WOMAC and SF-12 scores but similar change scores and decreased post-operative range of motion compared to their male counterparts. Patients with rheumatoid arthritis had significantly inferior pre-operative and post-operative HRQL indices, but similar change scores. Rheumatoid patients achieved greater post-operative range of motion than patients with osteoarthritis. Patients with a body mass index > 30 had significantly less pre-operative and one year range of motion, but beyond two years follow-up health-related quality of life indices and range of motion were similar to other BMI categories. Pre-operative deformity did not affect patient outcome. Pre-operative range of motion had a significant effect on post-operative range of motion. Comparable outcomes were achieved with both posterior cruciate ligament preserving and sacrificing total knee replacements; however, the posterior cruciate ligament sacrificing implants had significantly greater postoperative range of motion.
With a contemporary total knee replacement with 98% Kaplan-Meier survivorship at nine years, male gender, a diagnosis of osteoarthritis and a good pre-operative range of motion were indicators of improved post-operative outcomes. Change scores of health-related outcomes are a better indicator of efficacy than simply noting pre- and post-operative scores.
To compare posterior cruciate ligament substituting (PCS) total knee arthroplasty (TKA) and posterior cruciate ligament retaining (PCR) total knee arthroplasty (TKA) to determine if greater overall flexion is obtained with the PCS TKA versus the PCR TKA at two year postoperative follow up. Secondarily, to determine whether there is a difference in the recovery of range of motion over time between the two groups from initial presentation, to discharge, and to follow up visits at three months, one year, and two years.
Prospective, randomised double-blind clinical trial consisting of one hundred male and female patients scheduled for primary TKA. Sample size allows detection of a difference of six degrees of knee range of motion using two-tailed tests, =0.05, and 0.20 (80% power). SCORPIO PCL substituting total knee system and the SCORPIO PCL retaining total knee system were implanted for evaluation in this study. Patients were assessed at initial presentation, at postoperative discharge from hospital, and at follow up visits at three months, one year and two years for flexion knee range of motion. Additional data were collected utilizing the WOMAC Osteoarthritis Index, the Knee Society Clinical Rating Scale, the SF-36, and the Knee Society Radiographic Evaluation as well as data on length of stay and surgical time.
Subjects were similar in demographic characteristics and all measurements at the baseline initial assessment. No differences were seen in knee flexion at two year follow up as measured using an independent t-test (p> 0.05). Recovery of knee range of motion over time was not different as measured using a two way repeated measures ANOVA (p=0.88 for group effect).
Postoperative flexion and recovery of kneww range of motion was not altered following TKA by using PCS or PCR prostheses.
In patients with previous patellectomy the optimal constrained implant is not well understood. Previous outcome studies have shown contradictory results. There interpretation is limited by small number of patients, included primary and revision implants or involved a heterogeneous group of different constraint implants.
We performed retrospective match controlled analysis of a posterior stabilised primary total knee arthroplasty in forty-two patients who had previous patellectomy. There were nineteen male and twenty-three female patients. The average age of patients at the time of surgery was fifty-nine years (range from forty-one to seventy-four years). The average time from patellectomy to total knee arthroplasty was seventeen years (range from one to thirty-four years). The average duration of follow-up was 5.3 years with minimum two years follow up (range from two to sixteen years). The control group was matched by age, sex, prosthesis type and surgeon. We used the student-t test to compare the outcome measurement.
Preoperatively, the patellectomy and control groups were not significantly different in terms of Knee Society clinical and functional scores or range of motion. Postoperatively clinical component of the knee society score had a significant difference (p< 0.05) however the functional part of the knee society score didn’t (p> 0.05). In patellectomy group the postoperative clinical and functional score were equal to seventy and fifty-eight respectively. The average clinical component of knee society score in the patellectomy group was twelve points (SE=4.8) lower compare to the knee with intact patella. The patellectomy group also had higher extension lag and poorer extension (higher flexion contracture) at the most recent follow up (p< 0.05).
This study demonstrated the outcome of the largest series of primary total knee arthroplasty with posterior stabilised implant in patient with previous patellectomy. The outcome of surgery was significantly improved but not as good as the knee with intact patella especially the function of the extensor mechanism.
There were more than 574,000 primary lower limb total joint arthroplasties performed in the United States in 2002 and 48,000 in Canada over approximately the same period. The incidence of clinically apparent myocardial infarction following lower limb arthroplasty has been previously reported at 1.8% (Gandhi et al, 2006). The functional outcome of patients suffering post-operative myocardial infarctions has never been reported to our knowledge. Our hypothesis is that functional scores of patients undergoing total joint arthroplasty that suffer peri-operative myocardial infarction will be lower than in our control patients.
Patients were retrospectively identified from a prospectively collected database of total joint arthroplasties performed at one center. Six surgeons performed 3320 primary lower limb arthroplasties over a period of seven years. Patients of interest were identified via discharge summaries to have suffered a myocardial infarction diagnosed clinically and confirmed by biochemical assay. These patients were then case matched for demographics, risk factors and pre-operative functional score.
Sixty-two patients (twenty six hips and thirty six knees) were identified as having suffered a post-operative myocardial infarction. There was an overall mortality of 13% and only thirty-four of the sixty-two (55%) completed follow-up to one year. The clinical course of the remaining patients remains uncertain. Statistically significant differences have been observed in Oxford hip scores at six weeks post operatively. Any differences disappear by six months. No statistically significant differences in outcomes were seen in knee outcomes.
It would appear that those patients who are well enough to return for follow-up do just as well as those patients who did not suffer myocardial infarctions. There may be some differences in the rate of recovery from the surgery, but it appears that overall functional outcome of the patients that survive remain good.
The purpose of this study was to first determine if neuromuscular scoliosis results in greater peri-operative transfusion requirements compared to idiopathic scoliosis, and secondly to compare the effects of tranexamic acid (TXA) dosing on reducing transfusion requirements in scoliosis surgery. Previous studies have suggested that patients with neuromuscular scoliosis tend to have more blood loss during scoliosis corrective surgery as compared to patients with idiopathic scoliosis. Tranexamic acid has not been studied extensively in these populations and consensus regarding appropriate dosing has not yet been elucidated. A retrospective chart review of all patients who underwent posterior instrumentation and fusion for scoliosis for the years 1999 to 2006 was performed. Peri-operative transfusion requirements for idiopathic and neuromuscular scoliosis patients were compared and grouped according to TXA use. Transfusion requirements for those patients receiving either a low (10mg/kg loading, 1mg/kg/h infusion) or high (20mg/kg loading, 10mg/kg/h infusion) dose TXA were also compared.
Idiopathic patients had significantly decreased transfusion requirements overall (no TXA: idiopathic 1028.3 ± 558.7ml vs. neuromuscular 1400.7 ± 911.3ml, p = 0.02; with TXA: idiopathic 1082.9 ± 1005.5ml vs. neuromuscular 2043.8 ± 1397.5ml, p = 0.03). In the idiopathic group, high dose TXA resulted in a significant reduction in peri-operative transfusion requirements compared to low dose TXA (687.9 ± 778.1ml vs. 1355.0 ± 965.8ml, p = 0.04).
Neuromuscular scoliosis patients have significantly higher transfusion requirements as compared to idiopathic patients. For patients with idiopathic scoliosis, the use of the high dose TXA is suggested over low dose TXA given the relative reduction in transfusion requirements for the high dose group.
To determine the range of in-vivo magnification error in lateral spinal digital radiographs, and determine the effect of BMI on this error.
An analysis of two hundred and fifty patients with digital radiographs and CT/MRIs was performed. Digital imaging software was used to measure the antero-posterior vertebral body dimensions (VBD) at C2, C5, L1, and L4. Magnification values were determined in comparison to CT/MRI. CT measurements were also compared to MRI. BMI for each patient was obtained by chart review.
The difference between the mean VBD as measured on CT and MRI was < 0.1mm (n=130, p< 0.2514, paired t-test). Mean magnification at the cervical spine was 21% (1.21 ± 0.01; range = 1.06–1.57 (n=177)) and 31% at the lumbar spine (1.31 ± 0.01; range = 1.09–1.63 (n=284)). Linear regression showed a significant positive correlation between BMI and magnification at both the cervical and lumbar spine (Cervical: n=96; p=0.0019; Lumbar: n=144; p< 0.0001). There was a significant difference in magnification between non-obese and obese patients at both the cervical and lumbar levels. Cervical: 1.19 ± 0.01 magnification for non-obese (n=136), versus 1.26 ± 0.01 for obese (n=39) (p< 0.0001). Lumbar: 1.28 ± 0.01 (n=207), versus 1.38 ± 0.01 (n=71) (p< 0.0001), respectively.
Linear in-vivo measurements obtained on digital radiographs are subject to magnification errors at both cervical and lumbar spine. This error correlates to the patient’s BMI. Consequently, clinical-decision making, regardless of the anatomical area, that is based on linear measurements obtained from radiographs that do not account for this error are invalid. In the scenario that this measurement is crucial (e.g. dynamic radiographs), this error can be corrected by comparison to morphometric data from CT/MRI.
There is an increasing trend towards performing a high tibial osteotomy (HTO) with a medial opening wedge technique. Amongst the potential advantages is easier conversion to a total knee replacement (TKR), although literature regarding this is scarce. We report our early clinical and radiological results, along with the technical issues encountered.
From our database, we identified thirty-one patients who had undergone thirty-two TKRs after medial opening wedge HTOs. Clinic and operative records were reviewed, and our database used for knee society scores. Those patients not seen in the last twelve months were reviewed in clinic. All pre- and postoperative radiographs were reviewed. The average age of the patients was fifty-seven years, and the average time from HTO to TKR was 4.5 years.
Difficulties with patella eversion were seen in 12.5%, and the knee balanced easily in 85% of cases. The tibia had minimal deformity in most cases, and all osteotomies were healed at the time of conversion. A stem was used in ten cases, and only if metalwork was removed at the time of conversion (which was done in twenty-three of the thirty-two). Minimum one year follow-up was available for twenty-six patients, with a mean follow-up time of twenty-eight months (range twelve to ninety-three months). The average Knee Society knee score was eighty-eight, function score seventy-five, and total score one hundred and sixty-two. Compared to non-matched group of 1149 primary TKRs (of older average age), the knee score was significantly lower, and there was a higher percentage of patients in the poor category. Poor results correlated strongly to the presence of chronic pain or workers compensation issues, and also to whether the knee had undergone revision HTO prior to TKR.
We conclude that the conversion of a medial opening wedge HTO to a TKR is relatively straightforward technically, and some aspects are easier than performing a TKR after a lateral closing wedge osteotomy (using historical controls). The clinical results appear inferior to that of a TKR performed without a prior osteotomy, although the results in our osteotomy group were skewed by a small group of chronic pain and workers compensation cases.
To evaluate risk factors and outcomes of spondylodiscitis in hemodialysis patients.
Retrospective case control study of twenty-two spondylodiscitis patients and forty-four control subjects.
The incidence of spondylodiscitis was 8.3 cases per 1000 patient-years. Spondylodiscitis patients had been receiving hemodialysis for a significantly longer average duration (median, thirty-seven months) than control subjects (median, thirteen months; P < 0.0008). A greater proportion of spondylodiscitis patients (eighteen [82%] patients) than control subjects (six [14%] subjects; P < 0.0001) had microorganism growth from at least one blood culture within three months before diagnosis of spondylodiscitis. During the months before spondylodiscitis diagnosis, a significantly greater proportion of spondylodiscitis patients than control subjects had received blood products, had an invasive procedure, had any type of vascular access established, or had temporary or permanent internal jugular or temporary femoral central venous catheters placed. All patients with spondylodiscitis received antimicrobial therapy (mean duration, twenty-one ± fourteen weeks). The death rate was significantly greater for spondylodiscitis patients (thirteen [59%] patients) than control subjects (twelve [28%] subjects; P < 0.03; odds ratio, 2.69; 95% confidence interval, 1.03 to 7.04).
Risk factors for spondylodiscitis in hemodialysis patients include antecedent bacteremia, receipt of blood products, invasive procedures, or establishment of vascular access. Spondylodiscitis in hemodialysis patients has a poor prognosis and high risk of mortality.
To identify the presence of the Adamkiewica artery before operating spine tumor patients and avoid neurological complications as well as evaluate the impact on surgical strategy.
All tumor patients requiring spinal fixation from Feb 2002 to March 2006 were prospectively enrolled in the study. Included patients either had a primary spine tumor or a spine metastasis. Patients underwent a selective arteriography of the level above, the level below and the level involved by the tumor in order to document any Adamkiewicz artery (AKA).
Eighteen patients were enrolled. Six had a primary tumor and twelve had a metastasis between levels T1 to L3. There were no complications related to the radiological procedure. For ten (55%) of patients, the AKA was identified during the selective arteriogram. In seven of the twelve (58%) metastatic cases the AKA was found adjacent to the involved level. In 60% of cases the AKA was found on the left side. In all cases where the AKA was found, the surgical strategy was modified in order to preserve the AKA. No patients had permanent neurological complications.
The location of the AKA is extremely variable. in more than half our cases, the AKA was found immediately adjacent to the involved level. This could suggest a vascular explanation for the location of tumors in the spine. The vicinity of the AKA to the tumor site may explain why neurological complications are frequent when operating such spine cases.
Tumour cells induce osteolysis by producing multiple cytokines that indirectly activate osteoclasts; this process is dependent upon surface expression of a protein known as “receptor activator of nuclear factor kB ligand (RANK-L)” on osteoblasts (OB), and subsequent osteoclast (OC) interaction via surface expressed RANK. Harnessing this RANK-RANK-L interaction has potential for reducing cancer osteolysis. The aim of this study is to prevent tumour-induced osteolysis by ablating osteoclast activation.
A monocyte cell line (RAW 264.7) was grown in vitro in the presence of RANK-L and recombinant mouse macrophage colony stimulating factor (rmM-CSF) to produce osteoclasts. Tumour-associated cytokines IL-1a, TNF-a, and IL-6, and the regulatory cytokine osteoprotegerin (OPG) were added to assess osteoclast cell number (cytospin analysis with TRAP staining) and function (resorption pit number on dentine slices). Short interfering sequence of RNA directed towards RANK receptor (RANK RNAi) was used to assess the effect of abrogating RANK-RANK-L signaling in this pathway.
Tumour-associated cytokines failed to significantly alter OC cell number or function in the model tested. When TNF-a, IL-1a, and IL-6 were added together, the effect on OC function was variable, without a clear trend towards OC activation. The addition of the cytokine OPG revealed a trend towards reducing OC function, but this did not reach statistical significance. RANK RNAi also revealed a trend towards reducing OC function in the presence and absence of tumour-associated cytokines.
Tumour associated cytokines failed to enhance OC function using the monocyte cell line RAW 264.7. Both OPG and RANK RNAi revealed a trend towards reducing OC function, although further testing is required to confirm this observation. Future direction with include analysis of fresh bone marrow-derived OC, which may be more appropriate for this model.
Giant cell tumor (GCT) of bone is an osteolytic tumor that is locally aggressive and potentially metastatic. The pathogenesis of GCT is poorly understood. The purpose of this study was to harvest and culture primary cell lines from clinical specimens of GCT of bone and identify specific bone degradation proteases (matrix metalloproteinases: MMP-2, MMP-9) produced by the neoplastic stromal cells in vitro.
With approval by the McMaster University Biohazards and Ethics Review Boards, we acquired consent from five patients with GCT of bone, and harvested specimens intraoperatively. The specimens were chopped in DMEM containing 10% Fetal Bovine Serum, 2 mM L-glutamine, 100 U/ml penicillin and 100 mg/ml streptomycin. The cell suspensions were incubated at thirty-seven degrees (5% CO2 and 95% air) and cultivated. The cells were grown to confluence and taken through several passages until only proliferative cells were present. Immunocytochemistry with TRAP (Tartrate Resistant Acid Phosphatase) was used to confirm the stem cell origin of the propagative cells. Protein electrophoresis with embedded gelatin was used for detecting protease activity (MMP-2, MMP-9) on cell lysates and medium. P-aminophenyl mercuric acetate (APMA) was used to activate and ethylenediaminetetraacetic acid (EDTA) was used to block MMP-2 and MMP-9 activity. Our controls included serum free media, Human Osteosarcoma and Fibroblast cell lines.
Immunocytochemistry with TRAP confirmed that our propagative cells were not hematopoietic in origin but rather mesenchymal. Protein electrophoresis on cell lysates and medium identified the protease activity of MMP-2 and MMP-9 with lytic bands at appropriate molecular weights. APMA activated MMP-2 more than MMP-9, as indicated by increased relative density of bands. EDTA blocked the activity of both MMPs.
Our study confirmed the ability to cultivate the neoplastic stromal cells of GCT of bone from clinical specimens. Protein electrophoresis showed that activated MMP-2 and MMP-9 are secreted from the neoplastic stromal cells in vitro, suggesting a role for the tumor cells in bone destruction. These results are intriguing, as novel therapies in specific MMP inhibitors are currently underway for numerous disease processes.
Pigment epithelium-derived factor (PEDF) is the most potent endogenous inhibitor of angiogenesis and decreased PEDF expression has been shown, in many tumours, to be associated with increased intratumoural microvascularity, enhanced tumour growth and metastases and poor patient prognosis. We evaluated the role of PEDF in osteosarcoma growth inhibition and examined it’s potential as a possible anti-cancer therapeutic agent.
We investigated the effects of overexpressed and recombinant PEDF (rPEDF) in several cell-based assays and in two orthotopic models of osteosarcoma (UMR 106-01 and SaOS-2).
In vitro, overexpression of PEDF significantly decreased cell proliferation, migration, invasion and increased adhesion to collagen-1. rPEDF resulted in a dose-dependent inhibition of cell proliferation, increased collagen adhesion, decreased invasion, and down-regulation of VEGF. The pro-differentiation ability of rPEDF was confirmed by upregulation of several osteoblastic markers after treatment of a pre-osteoblastic cell line (UMR 201). Furthermore, both cell lines displayed increased mineralised nodule formation after administration. In vivo, PEDF inhibited osteosarcoma growth and metastasis when overexpressed and in the recombinant form. In addition, anti-tumour activity was observed upon testing with shorter peptides of PEDF. Pharmacoevaluation of rPEDF demonstrated stability within media over several days, and no significant side effects in terms of wound healing.
From these results, PEDF demonstrates multi-modal anti-tumour activity via anti-proliferation, anti-angiogenesis, pro-differentiation and anti-metastasis. PEDF may be a promising therapeutic agent for the treatment of patients with osteosarcoma.
Bone metastases from renal cell carcinoma are aggressive, osteolytic lesions that often require operative intervention for fracture prophylaxis, fracture fixation or palliation. The lesions are hypervascular and intraoperative bleeding is a serious challenge for the orthopaedic surgeon. The purpose of this study was to determine the efficacy of preoperative tumour embolization in reducing blood loss during operative management of renal cell carcinoma metastases to bone.
Patients were identified from a prospectively accumulated database (1996–2006). Inclusion criteria included operative management for renal cell metastasis to the pelvis or appendicular skeleton. Patients that were not embolised preoperatively due to renal insufficiency or obesity were excluded. Embolizations were performed the day of surgery by an interventional radiologist. Post-embolization runs were used to determine the percentage of blood flow reduction to the tumour. Variables analyzed included patient age, gender, location of tumour, surgical procedure, surgical time, number of units of packed red blood cells (PRBC) transfused, estimated intraoperative blood loss (EBL) and percentage embolised according to the post-embolization run. Student’s t-test was used to determine the effects of percentage embolization on EBL and number of units of transfused PRBCs.
Thirty-five cases (twenty-eight patients) met the inclusion criteria. There were twenty males and eight females with an average age of sixty-five years (range, forty-three to eighty-nine years). The most common metastatic sites were the femur (nineteen cases), humerus (seven cases) and pelvis (six cases). There were ten cases of intramedullary nailing and twenty-five cases of tumor resection and reconstruction. Average surgical time was 4.5 hours (range, 0.75–10 hours) and average EBL was 1.5 litres (range, 0.25–12 litres). Embolization that successfully blocked at least 75% of the blood flow to the tumour significantly decreased surgical EBL (3.2 vs 0.6 litres, P< 0.05) and units of PRBCs transfused (5.6 vs 1.9, P=0.05) compared to those that did not. Two embolization-associated complications occurred including one case of toe gangrene and one case of muscle ischemia.
Preoperative embolization significantly reduces blood loss and red blood cell transfusions resulting from surgical stabilization of renal cell metastases to bone. Close communication between the orthopaedic surgeon and interventional radiologist is imperative to maximise these benefits.
To investigate the outcome of operative procedures designed to reduce the likelihood of neurovascular injury, fracture and tumor recurrence. The literature frequency of neurovascular injuries is about 10% and recurrences have been reported to be common when resections are undertaken before skeletal maturity. Prospective analysis of the outcomes following resection of exostoses in two hundred and fifty children and adolescents. Preoperative CT-angiograms iwere undertaken in patients with multiple exostoses surrounding the shoulder, knee and hip joints. Peduculated exostoses were removed by detaching the base and retrogradely removing the lump. Broader based exostoses were opened and decancellated so that the cap could be collapsed down away from adjoining and adherent neurovascular structures. This approach also enabled the cap to be separated from adjacent bone such as the pelvis or fibula with femoral or tibial exostosis, respectively. The outcomes included assessments of neurovacular status, bone healing and recurrence after five years. No patients had early or late evidence of neurovascular damage although the neurovascular structures were adherent to many of the exostoses.
No patients had recurrence of their exostoses which was likely due to most of them having being removed after skeletal maturity. In addition, the cortical defect left by the resections healed with six to nine months of the surgery.
Our conclusions are to remove exostoses after skeletal maturity in order to minimise recurrence risk. Use preoperative CT-angiograms with large solitary or multiple exostoses to aid in operative planning. Decancellate large exostoses in order to collapse the cap away from adherent neurovascular and skeletal structures.
This study examines the biomechanical performance of five types of fixation techniques in a model of pathological fracture of the diaphyseal humerus.
In forty synthetic humeri, a hemi cylindrical defect centered in the middle third of the diaphysis was created. A transverse fracture was created through the centre of each defect. The bones were randomly assigned to five groups. Group A was fixed with standard ten hole DCP plates centered over the defect with five screws inserted on either end. In group B, the screw holes were injected with bone cement and then the screws and plate were reapplied while the cement was still soft. The defect was also filled with cement. Group C was fixed by injecting the cement into the entire intramedullary canal. The fracture was then reduced and the screws and plate were applied once the cement had hardened. In group D, the specimens were fixed with locked antegrade IM nail with one proximal and one distal interlocking screw. Group E was same as D except that the defect was filled with cement. Each specimen was tested in external rotation to failure by fracture.
There was no significant difference in torsional stiffness between groups B, C, and E (P> 0.16), whereas there were differences between all other groups using pairwise comparisons(p< 0.001). Groups B, C, and E were of highest stiffness followed by A and then D. Group C had the highest torque to failure, followed by groups A/B and then D/E. Total cumulative energy to failure for group C was statistically greater than each of B, D, and E (p< 0.005), but not different from A, though it approached significance (p=0.057).
This study demonstrates that, in a model of a fracture through a hemicylindrical defect in the middiaphysis of the humerus, fixation with a broad ten-hole dynamic compression plate after filling the entire medullary canal with cement is associated with the highest torque to failure and energy to failure with torsional forces. This fixation technique may best accomplish the clinical goal of maximal initial stability.
We report a series of sixteen total hip arthroplasties utilizing a porous tantalum trabecular metal acetabular component in patients with tumors of the hip.
The study included eight men and eight women with an average age of 59.3 (range 22–80 years). Two patients had benign but locally recurrent disease destructive of bone (Langerhan’s Cell Histiocytosis and Rosi Dorfman Disease), while fourteen had malignant lesions. The latter included six myeloma, two lymphoma, and six metastatic carcinoma (three breast, one prostate, one lung, and one unknown site). Fifteen patients had prior radiation therapy. The technique used was determined by the extent of the lesion and the quality of remaining host bone.
In eight patients major deficiencies necessitated augmentation of the porous tantalum cup with an anti-protrusio device “over -the top” a cup-cage construct. Porous tantalum augments were utilised with the cup to fill defects in the acetabulum in seven patients. Postoperative complications were seen in four cases (DVT, DIC, pneumonia, and one death from c. difficile colitis).
Postoperatively, the majority of the patients had excellent pain relief and improved ambulatory status. No clinical failures have been observed at follow-up (mean 12.5 months, range twenty days-twenty-eight months). There have been no re-operations. Radiographically, no migration or evidence of implant loosening has been observed.
Radiation induced pathologic fractures present a difficult problem for musculoskeletal oncologists. The purpose of this study was to determine the outcomes of management of radiation-induced pathologic fractures in a group of patients who had previously undergone combined management of extremity soft tissue sarcoma.
A review of our retrospective database was undertaken. From 1986 to present, thirty-two patients with soft tissue sarcomas were found to have radiation induced pathologic fractures. The records of these patients were reviewed for patient demographics, tumour size and anatomic site, presence of periosteal stripping at time of surgery, radiation dose, time to fracture, fracture treatment and fracture outcome.
There were twenty-three females and nine males with a mean age of sixty-three (range thirty-six to eighty-nine) years. Fractures occurred at a mean of forty-five months after resection of the sarcoma (range three to one hundred and fifty months). Anatomic distribution of fractures were : proximal femur(twelve), femoral diaphysis (eight), distal femur (two) tibia (five), acetabulum (two), metatarsal (two) and patella (one). Periosteal stripping was performed in half of the patients. Twenty-three patients had received high dose radiation (6600Gy). Seven fractures were managed conservatively while twenty-five were treated surgically. Only eleven of the thirty-two fractures united. Six patients underwent amputation, three for local recurrence and three for non-union of their fracture. Eight patients ultimately underwent arthroplasty, while seven patients have persistent non-unions. In the proximal femur, only three out of twelve fractures healed while six patients eventually underwent arthroplasty and three continue to have non-unions. Of eight femoral diaphyseal fractures, only one united. Patients who eventually underwent prosthetic replacement had good function and pain relief.
Radiation induced pathologic fractures are a difficult clinical problem. In particular patients with fractures in the proximal femur often undergo multiple attempts at fixation before definitive management with resection and endoprosthetic replacement. Fractures of the femoral diaphysis rarely heal despite aggressive surgical management. Primary arthroplasty may be considered in some patients as an alternative to fixation in radiation-induced pathologic fractures of the femur in order to avoid long term morbidity and repeated operations.
Early fracture stabilization has been shown to reduce morbidity and mortality in the patient who is multiply injured. Controversy exists in terms of managing multiple trauma patients who sustain thoracic injuries along with femoral shaft fractures. The purpose of the present study was to determine whether the presence and treatment of femoral shaft fractures increases morbidity in patients with pulmonary contusions and to determine the effect of patient and surgical factors on outcome.
Patients that suffered chest injuries between January 1987 and April 2006 were identified from the prospectively collected trauma databases at two hospitals. Patient records were reviewed to verify all data. The diagnosis of pulmonary contusion was confirmed with radiologic or post-mortem investigations. All relevant patient and surgical data was collected. Exclusion criteria included severely injured patients (head/abdomen AIS> 3), age sixty years, death twenty-four hours after injuries occurred.
A total of 1190 patients with confirmed pulmonary contusions met inclusion criteria; there were 113 femoral shaft fractures (five bilateral). Patients in both the isolated pulmonary contusion and pulmonary contusion with femoral fracture had similar injury severity scores (ISS) and demographic information. Fractures were reduced with intramedullary nailing in 88% of cases. Mean age was thirty-five years. There were significantly more incidences of fat embolism syndrome and acute lung injury (ALI) in patients with femoral factures (twenty-four hours following the injury had significantly greater risk of developing ARDS (p< 0.05).
The presence of femoral shaft fractures in patients with pulmonary contusions increases the duration of admittance to hospital and can lead to higher rates of fat embolism syndrome and ALI, however it does not appear to impact overall mortality or contribute to the development of other common respiratory complications. Early reduction of shaft fractures is encouraged to further decrease complications.
Fat embolism syndrome (FES) is a potentially lethal condition commonly seen in poly-traumatised patients, particularly those with multiple long-bone fractures. Treatment has centered around supportive care and early fracture fixation. Several clinical small trials have suggested corticosteroids benefit patients with FES but its use remains controversial. Our objective was to determine the effect of corticosteroids in preventing FES in patients with multiple long-bone fractures.
We conducted a meta-analysis of randomised trials, searching computerised databases for published studies from 1966–2006. Additionally, we performed hand searches of major orthopaedic journals, meeting proceedings, and texts. Our primary outcome was the rate of FES. Secondary outcomes included presence of hypoxia, petechiae, mortality, infection, and delayed union.
Of the one hundred and four studies identified, nine were potentially eligible, and only seven met all our eligibility criteria. From our pooled analysis of three hundred and eighty-nine patients, we found that corticosteroids reduced the risk of FES by 78% (95%CI: 43–92%, heterogeneity p-value=0.62, I2=10%) and that only eight patients needed to be treated (NNT=7.5) to prevent one case of FES (95%CI: five to thirteen patients). We did not find any significant differences in the rates of mortality, infection, or delayed union.
The current evidence suggests that the use of corticosteroids is beneficial in the prevention of fat embolism syndrome in patients with multiple long-bone fractures. The use of corticosteroids does not appear to significantly increase the risk of complications although a confirmatory large randomised trial is needed.
This study is a prospective randomised clinical trial which primary objective was to demonstrate the safety and efficacy of a single posterior mini-incision approach compared to a standard posterior approach for hemiarthroplasty in acute femoral neck fractures.
Fifty-five patients have been randomised: twenty-four patients in the mini-incision surgery group (MIS) and thirty-one patients in the standard incision group (STD). The mini-incision was defined as less than 8cm. Data were collected preoperatively and at four days, three and six weeks, three, six, twelve, and twenty-four months postoperatively. The Jaglal Lower Extremity Measurement (LEM) and the Time Up and Go (TUG) where evaluated. Secondary endpoints of pain, function, and quality of life where assessed by the components of the Harris hip Score and SF-36. Radiograghic outcomes where also evaluated.
The demographic data where similar between the two groups for age, gender, weight, type of anaesthesia used, pre-operative haemoglobin and preoperative comorbidities. There was no significant difference for operative time, blood losses, 72h postoperative haemoglobin and the need for transfusion therapy between the two groups. Also, there was no difference between the groups for post-operative morphine use and pain evaluation with the Visual Analog Scale. The functional assessment using the LEM, TUG, Harris Hip score and SF-36 scores did not demonstrate any statistically significant difference between mini and standard incision.
This study demonstrates that the clinical and functional outcomes measured are similar between the two groups, thus limiting the potential benefits of MIS in hip fracture patients.
To investigate differences between the Reamer Irrigator Aspirator and the AO reamer on fat embolism outcome using a porcine model.
All animal procedures were approved and performed in accordance with the Animal Care Committee at St. Michael’s hospital. Following anesthetic administration, the animals were stabilised for thirty minutes. One third of the pig’s blood volume was withdrawn to simulate hemorrhagic shock. Each animal was kept in a state of hypovolemia for an hour before transfusion and resuscitation. Once the animal was stabilised surgical exposure of the distal femur was completed. A 12 mm Reamer Irrigator Aspirator or AO reamer was used depending on which group the animal was assigned to. Blood work was obtained at: baseline, immediately after induction of hypovolemia, one hour post hypovolemia, post stabilization, one minute, five minutes, 1.5 hours and three hours after reaming. The results were analyzed for activation of the coagulation system, platelet and neutrophil activation, and cytokine elevation. ANOVA was the primary tool used to assess statistical significance.
There was no statistical difference between the two reamers with respect to PT, APTT, and fibrinogen. There was a statistical difference in D-dimer at 1.5 and three hours post-reaming, with the RIA showing a lower value. Neither reamer demonstrated any systemic platelet nor neutrophil activation. TNF-alpha spiked immediately post-reaming with the RIA group returning to baseline values and the AO group remaining elevated. There is a spike in IL-1B post reaming in the AO group, however this was not seen in the RIA group. No statistical difference was detected between the two reamers.
All markers for platelet and neutrophil activation and the coagulation cascade were measured at the systemic level. Although there is no statistical difference between the RIA and AO reamer, it is possible that activated cells were removed from the systemic circulation and sequestered as thrombi in the pulmonary microvasculature. This hypothesis may be supported by a drop in platelet count and an increase in D-dimer, with the AO reamer suggesting greater thrombi formation. The trends in IL-1B and TNF-alpha seem to suggest that the RIA abrogates the post-reaming proinflammatory state.
Two of commonest types of hemiarthroplasty used for the treatment of a displaced intracapsular fracture are the uncemented Austin Moore Prosthesis and cemented Thompson hemiarthroplasty. We performed this trial to determine if any difference in outcome exist between these implants.
We undertook a prospective randomised controlled trial of four hundred patients with a displaced intra-capsular hip fracture. All operations were performed or supervised by one orthopaedic surgeon and all by a standard anterolateral approach. Patients were followed by a nurse blinded in the type of prosthesis to assess residual pain and mobility.
The average age of the patients was eighty-three years and 23% were male. 73% came from their own home with the remainder from institutional care. There was no statistically significant difference in mortality between groups. Pain scores were less for those treated by a cemented prosthesis (p value < 0.00001). Mobility change was also less for those treated with a cemented implant (p=0002). No difference was found in hospital stay, implant related complications, re-operations or post-operative medical complications between the two groups. One case of non-fatal intraoperative cardiac arrest occurred in the cemented group.
In summary a cemented Thompson Hemiarthroplasty causes less pain and less deterioration in mobility compared to the uncemented Austin Moore hemiarthroplasty, without any increase in complications. The continued use of an uncemented Austin Moore cannot be recommended.
The incidence of DVT and need for thrombo-prophylaxis following isolated distal lower extremity fractures is unknown. The purpose of this study was to determine whether or not thrombo-prophylaxis with low molecular weight heparin was needed in this trauma population.
A Multicentered Prospective Randomised Double Blind Placebo Controlled Trial was designed to define the incidence of DVT and need for thrombo-prophylaxis in this population. A sample size of two hundred and ninety-nine patients ensured a one tailed type one error of alpha = 0.05 and power of 80% as confirmed from previous studies. Males and female patients between the ages of eighteen and seventy-five years with isolated distal lower extremity fractures (excluding the foot) were eligible. All patients had surgery within forty-eight hours after injury. Patients excluded from the trial were polytrauma patients, those medically unfit for the operating room, patients with foot fractures, those receiving anticoagulation, inability to provide consent, platelets 200 umol /L. Randomization was carried out via computer generation to receive either placebo or Fragmin for fourteen days. At fourteen days, all patients underwent bilateral venograms interpreted by three independent radiologists. Equivocal venograms were interpreted by consensus. Routine follow-up was carried out for all patients at two, six, eight and twelve weeks.
A total of two hundred and ninety-nine patients were enrolled in the study. One hundred thirty-six patients in the Fragmin group and one hundred and twentyfive in the placebo group completed the intervention. There were one hundred and twenty-five males and one hundred and thirty-six females in total. There was no statistically significant difference in DVT incidence between those patients treated with Fragmin or Placebo (p = 0.41). Gender, medical issues, pre-operative level of activity and body mass index had no effect on the incidence of DVT.
The incidence of DVT in fragmin treated and placebo treated patients is 8.1% and 11.2%, respectively (p = 0.41). This study suggests that DVT thrombo-prophylaxis is not indicated in this patient population. To our knowledge, this is the first Randomised Controlled Trial utilizing venograms (gold standard) for DVT identification.
The primary objective of this study was to report the progression of functional status over time after hemiarthroplasty surgery for displaced femoral neck fractures in one hundred patients. One of the secondary outcomes was to determine factors predictive of bad outcome (age, co-morbidities, type of anesthesia, surgical approach, etc). Another secondary objective was to determine if early functional assessment correlates and/or predicts long term function. Finally, our group was compared to a normal control group database.
A hundred patients treated with hemiarthroplasty for Garden-type III and IV femoral neck fractures were evaluated prospectively using validated functional outcome measures. Baseline data and preoperative functional level was determined for all patients. Functional recovery was evaluated using the Lower Extremity Measure (LEM) and the Time Up and Go (TUG). Clinical outcome was equally measured using the Harris Hip Score and SF-36 (Short-Form 36). Follow-up was done at one and a half, three, six, nine, twelve and twenty-four months.
Preliminary results show that this study group is comparable to the group used in Jaglal et al.’s original study of the Lower Extremity Measurement score. LEM scores at one year follow-up are significantly lower than pre-operative scores. TUG scores at three months follow-up were significantly lower in the female sub-group in comparison to normal controls.
This study of patients undergoing hemiarthroplasty for femoral neck fractures demonstrates the significant post operative functional repercussions as shown by the deterioration of scores of functional outcome measures used. Predicting functional outcomes based on pre-operative patient baseline data and function is relevant in that it could potentially impact decision to operate and determination of surgical procedure of choice.
The objective of this study was to determine whether immediate mobilisation and unprotected weight bearing of rigidly internally fixed fractured ankles had a significant effect on ankle function or whether it predisposed the ankle to loss of reduction or hardware failure.
We retrospectively reviewed eighty-nine patients with unstable and/or displaced Weber type-A, B or C ankle fractures. Twenty ankle fractures who underwent open reduction and internal fixation. Post operatively the patients were either treated in a non-weight bearing plaster cast (Group A) or were allowed immediate full weight bearing as tolerated without a plaster (Group B. The treatment or weight bearing status was not modified for patients with syndesmosis injuries or deltoid ligament repair. For comparison, twenty-five patients of each group were matched to a same number of historic controls with respect to age, gender, body mass index, and fracture type.
The recovery of the patients was assessed clinically with use of subjective, objective, and radiographic evaluation criteria with reviews at ten to fourteen days, six weeks and three months and one year after the operation. The follow up ranged from twenty-four to fifty-eight months with an average follow up of 37.5 months. Matched-pair analysis revealed no differences for hospital stay and functional outcome (p= 0.858) on Olerud and Molander scoring system but significant difference in time until return to work (mean 91.3 ±20.2 vs. 54.6 ±15.5 days). In the cast group; one patient had loss of internal fixation and one had non-union while four patients in non cast group had mainly wound-healing related problems. Patients in non cast group tolerated earlier full weightbearing and there were no disadvantages concerning hospital stay, pain intensities, and functional Scores.
We conclude that immediate mobilisation and unprotected weight bearing of rigidly internally fixed fractured ankles does not predispose the ankle to loss of reduction or hardware failure and the functional results compared with the conventional cast immobilisation are comparable. In our opinion early mobilization without plaster is recommended in certain populations and may result in faster rehabilitation.
To determine if intraoperative positioning in the supine or lateral position affects morbidity and mortality in orthopaedic trauma patients with femur fractures.
Retrospective cohort study of 991 patients representing 1030 femoral shaft fractures admitted to our level one trauma center between the years of 1987 to 2006. Primary outcome measures included mortality and admission to ICU. Secondary outcome measures included length of stay in hospital, length of time admitted to the intensive care unit and discharge disposition. Logistic regression analysis was performed to compare to effect of intraoperative position in addition to other known dependent variables on primary and secondary outcome measures.
Intraoperative position in the supine or lateral position had no effect on morbidity or mortality in orthopaedic trauma patients with femur fractures.
There is no difference in immediate mortality or morbidity between patients with femur fractures treated with IM nails in either the lateral or supine position. We conclude that either position is safe for the surgical stabilization of femur fractures and intraoperative position should be determined by surgeon preference.
A neck of femur fracture is known to be a high risk factor for the development of pressure sores with an associated morbidity, mortality and cost. We have attempted to identify risk factors in these patients for the development of pressure sores
We have analysed prospectively collected data of 4654 consecutive patients (1003 males/3473 females).
3.8% developed pressure sores in the sacral, buttock or heel areas. Patients factors that increased the risk of pressure sores were increased age (82.1 years versus 76.6 years), lower mental test score (5.7 versus 6.7), diabetes mellitus (pressure sore incidence 9.4%), higher ASA score (3.0 versus 2.7) and lower admission haemoglobin concentration (120gms versus 124gms). Those patients with an extracapsular fracture were more likely to develop pressure sores compared to patients with an intracapsular fracture (4.5% versus 3.1%). Being male was not a risk factor. Among surgical factors related to an increased risk was a fall in blood pressure during surgery (5.6%). Patients who underwent a dynamic hip screw were more likely to develop pressure sores (pressure sore incidence 4.7%). Patients with an intracapsular fracture treated with internal fixation were less likely to develop pressure sores in comparison to those fractures treated with a hemiarthroplasty or a sliding hip screw (2.0% versus 4.7 versus 4.4%). No relationship was seen related to length of surgery of type of anaesthesia.
Our study indicates that the current incidence of pressure sores is lower that that previously reported (30%). Whilst it is possible in a large population of patients to determine factors that increase the risk of pressure sores, these are not sufficiently reliable to be used for an individual patient.
Femur fractures are a complication of hip arthroplasty. When the stem is well fixed, fracture fixation is the preferred treatment option. Numerous fixation methods have been advocated, using plates and/or allograft struts. The study was conducted to determine the biomechanical characteristics of three constructs currently used for fixation of these fractures.
Vancouver type B1 periprosthetic femur fractures were created distal to a cemented hip stem implanted in third generation composite femurs. The fractures were fixed with one of three constructs: 1- A non-locking plate and allograft strut (NLP-A) 2- A locking plate and allograft strut (LP-A) 3- A locking plate alone. (LP) The struts were held in place with cables. There were five specimens in each group. Following fixation, the constructs underwent sinusoidal cyclic loading from 200 to 1200 N for 100000 cycles. Stiffness of the constructs was determined in bending, torsion and axial compression before and after cyclic loading. Axial load to failure was also determined.
Overall, cyclic loading had little effect on the mechanical properties of these constructs. The two constructs with allografts were significantly stiffer in coronal plane bending than the construct consisting of only a locking plate. There were no significant differences in axial or torsional stiffness between the constructs. Load to failure of the NLP-A (4095 N) and LP-A (4007 N) constructs was significantly greater than the LP construct (3398 N) (p=0.023 and p=0.044 respectively).
All three constructs tested retained their mechanical characteristics following 100000 cycles of loading. Our initial concerns that the cables holding the allograft strut would loosen appear unfounded. Allograft strut-plate constructs are stiffer in bending and have a higher load to failure than a stand-alone locking plate. When an allograft plate construct is chosen, locking screws provide no mechanical advantage in this experimental model.
Between 1994 and 2006, 83 patients (84 elbows) underwent the Outerbridge-Kashiwagi (OK) procedure by the senior author. Of these, 30 patients with over 5 years follow-up where available for review. There were 24 males and 6 females mean age 59.8 (range 34 – 81). 27 patients had primary osteoarthritis and the rest developed post-traumatic arthritis. Mean duration of symptoms was 25.5 (range 12 – 72) months. 30 patients had more than 5-year follow-up with a mean of 96 months (range 60–150) months. Their mean pre-operative flexion improved from 115° (range 90° – 150°) to 134° (range 100° – 160°) post-operatively (p< 0.001) and mean pre-operative extension deficit improved from 28° (range 10° – 50°) to 13° (range 5° – 30°) post-operatively (p< 0.001). The mean MEPS improved from 52 (range 25 – 70) pre-operatively to 84 (range 55 – 100) post-operatively (p< 0.038). The mean pre-operative DASH score improved from 63 (range 37 – 92) to 41 (range 24 – 75) postoperatively (p< 0.001). The mean pre-operative DEORS improved from 6.3 to 4.9 post-operatively (p< 0.001). Majority of the patients [22 patients (73.3%)] returned to their previous work including all 5 professional sportsmen. There were few complications -2 superficial wound infections, and numbness along ulnar nerve distribution in 1 patient. Of the 17 patients who had recurrence after 5 years, 4 patients had to undergo revision surgery (3 improved). 23 patients (76.6%) were satisfied with the results of the surgery. Conclusions: The OK procedure gives excellent to good results in 70.9% of patients at a mean of 9 years. Both flexion and extension improved significantly with very few complications with this open surgical technique. Although 17 out of 30 patients had recurrence on X ray beyond 5 years, only 4 required revision procedures.
This study reviews the early results of elbow hemiarthroplasty for distal humeral fracture. Elbow hemiarthroplasty was performed on 30 patients (mean 65 years; 29–91) for unreconstructable fractures of the distal humerus or salvage of failed internal fixation. A ‘triceps on’ approach was used in 6 and an olecranon osteotomy in 24. A Sorbie Questor prosthesis (Wright Medical Technology) was used in 14 patients and a Lattitude (Tornier) in 16. Clinical review at a mean of 25 months (3 – 88) included the American Shoulder and Elbow Surgeons elbow outcomes instrument (ASES), Mayo Elbow Performance Index (MEPI) and radiological assessment. At follow up of 28 patients, mean flexion deformity was 25 degrees, flexion 128 degrees, range of pronosupination 165 degrees, mean ASES 83, MEPI 77 and satisfaction 8/10. Acute cases scored better than salvage cases. Re-operation was required in 16 patients (53%); 2 revisions to a linked prosthesis for periprosthetic fracture and aseptic loosening at 53 and 16 months, 12 metalwork removals and 4 ulnar nerve procedures. Posterolateral rotatory instability was present in one elbow, 4 had laxity and pain on loading (2 with prosthesis or pin loosening), 4 had laxity associated with column fractures (2 symptomatic) and 10 had asymptomatic laxity only. The triceps on approach had worse laxity and clinical scores. Uncomplicated union occurred in all olecranon osteotomies and 86% of column fractures. One elbow had an incomplete cement mantle and 7 had lucencies > 1 mm; one was loose but acceptable. 5 prostheses were in slight varus and 2 were flexed. 2 elbows had early degenerative changes and 15 an osteophytic lip on the medial trochlea. Elbow hemiarthroplasty has good early results after complex distal humeral fractures, despite a demanding procedure, metalware removal in 40%, symptomatic laxity in 12% and column non-union in 8%. Better results are obtained for treatment in the acute setting and with use of an olecranon osteotomy.
Total elbow arthroplasty (TEA), as a primary procedure and open reduction and internal fixation (ORIF) have been used to treat complex intra-articular distal humeral fractures in elderly patients. The failure rate after ORIF is high and TEA has often been used as a salvage procedure. Although satisfactory results have been reported after TEA as a primary procedure, there are no publications reporting the results of TEA after failed internal fixation (FIF). In this study we compared the results of patients that had TEA after FIF with those that had had primary arthroplasty (PA). We reviewed the results of 9 consecutive patients who had FIF with 12 patients who had PA. All the operations were performed by one surgeon using the same technique and same prosthesis. Both groups of patients were similar with respect to ages, sex, co-morbidity and hand dominance. The mean follow-up for both groups of patients was 5 years. At final review, patients who had had FIF had a mean Mayo score of 68 and a range of flexion/extension of 90 degrees, there was 1 infection and 1 case of loosening. The PA group had a mean Mayo score of 88 and a range of flexion/extension of 96 degrees, there were no cases of infection or loosening. This study shows the results of TEA are satisfactory either as a PA or after FIF, however the results after PA are significantly better than after FIF.
Between 1994 and 2006, 58 patients underwent decompression of radial tunnel. The senior author using an anterior approach performed all procedures. 43 patients were available for follow-up evaluation at an average of 47.3 months (12–156 months). The average age of patients was 49.7 years (35 – 72 years) and the mean duration of their symptoms was 18 months (6 – 56 months). There were 12 patients (13 extremities) over 5 years follow-up. All had a trial of conservative treatment with steroid injections, physiotherapy and ultrasound therapy. All except 2 had nerve conduction studies which were inconclusive. The results were evaluated using Mayo elbow scores and DASH scores. Mayo scores improved from a mean of 62.37 pre-op to 87.13 post-op (p< 0.05) and DASH scores improved from 67.58 pre-op to 40.12 post-op (p< 0.04). 35 patients (81.3%) were satisfied with the surgery while 8 patients were not (4 patients had other pathologies). There were few complications – neuropathic pain-1, neuropraxia – 1 and residual pain – 2. Six patients who had simultaneous release of lateral epicondylar muscles and radial tunnel did extremely well and were satisfied. Hence there is a role for simultaneous decompression of tennis elbow and radial tunnel as recent studies suggest that extensor carpi radialis brevis tendon forms a continuous fascial sheath from lateral epicondyle to radial tunnel structures blending with supinator muscle. Based on our results, surgical decompression of radial tunnel gives good results in majority of patients with persistent radial tunnel symptoms with long-term relief.
Tension band wire fixation continues to be the most popular method of fixation for displaced olecranon fractures despite several biomechanical studies questioning the validity of the tension band concept. Our aim was to compare the outcome of the tension band wire (TBW) method with plate fixation. 58 consecutive olecranon fractures underwent internal fixation in 58 patients between September 2000 and December 2004. There were 30 male and 28 female with a mean age at the time of surgery of 52.5 years for the TBW group (range 19 to 88) and 46.1 for the plate group (range 19 to 72). Patients were excluded if they were less than 16 years of age. Choice of fixation was based on surgeon preference, fracture pattern and presence of associated injuries. 43 patients were managed with the AO tension band technique and 15 with plate fixation. Clinical assessment and functional analysis was performed using Helm’s scoring system. Radiographic assessment was performed to assess the quality of reduction. All fractures were displaced and classified according to Colton’s classification. Mean follow up was 13 months (range 6 to 18) and similar for the two groups. For the TBW group 41 (95 %) had a fair or good result. 27 (62.8%) patients had symptomatic metal prominence requiring implant removal. In the plate fixation group 14 (94%) had a fair or good functional result despite having more complex fractures. Only 2 (18%) patients required implant removal for symptomatic metalwork, including one failure due to a technical problem. Similar functional results were seen with plating and tension band wiring of displaced olecranon fractures. Despite meticulous technique, tension band wire fixation still has an unacceptably high complication rate with symptomatic metal prominence requiring further surgery. To avoid this problem, we recommend plating, even for the more simple olecranon fractures.
The aim of this study was to review the outcome of semi-constrained total elbow arthroplasty (TEA) in osteoarthritis and compare it to the rheumatoid group. This was performed on a single-surgeon, single-prosthesis (GSB III) series of patients. Two groups of patients assessed. In the first group with the diagnosis of rheumatoid arthritis 40 replaced elbows in 31 patients (25 female and 1 male), with average age of 67 (range 49–82) were reviewed. The second group consisted of 14 elbows in 14 patients (9 female and 5 male) with post-traumatic osteoarthritis. Average age in this group was 71 (range 54–84). All patients were recalled for clinical review. Fresh radiographs obtained and compared to the immediate postoperative images. Mayo elbow performance (MEPS) and Liverpool elbow scores (LES) were used as the outcome measure. Kaplan-Meier survival analysis for the two groups was performed. The average follow up for the first group was 53 (range 20–90) and second group 60 months (range 21–103). According to the MEPS 87.1% of patients in group 1 and 63.6% in group 2 had excellent or good outcome. This different was not statistically significant (p=0.09). Only one patient from group one and none in group two had the joint revised. No significant difference was observed in MEPS of group one (86 ± 17) and group two (77 ± 24), (p=0.25). Also the LES in the two groups were not different (p=0.85) (group one 8 ± 1 vs. group two 8 ± 2). The outcome of TEA is satisfactory in both groups. No statistically significant difference was noted in the two groups. The recommendation of TEA in patients with osteoarthritis is supported by this study.
Total elbow arthroplasty (TEA) has been shown to be a treatment option for elderly patients with complex distal humeral fractures and osteoporotic bone. The published results have often included rheumatoid patients who traditionally would be expected to do well from elbow arthroplasty. Only short-term results have been published using this technique in non-rheumatoid patients The current study contains the largest number and longest follow-up of non-rheumatoid patients whose fractures have been treated with a non-custom TEA. In total there were 26 patients, mean age 72 years, 22 female and 4 male, 25% dominant arm. All had a minimum of 5 years follow-up. There was 1 case of loosening, 1 radial nerve palsy and 2 cases of heterotrophic ossification. At final review the mean range of flexion/extension was 97.5 degrees and the mean range of pronation/supination was 151.75 degrees. The mean Mayo Elbow Performance score was 92. We would suggest that TEA provides a very satisfactory outcome in elderly patients with complex distal humeral fractures, the benefit of which can be observed for at least 5 years.
We describe a new a technique for reconstructiing the ulnar collateral ligament (UCL) of the elbow, and test this new technique biomechanically comparing it with an established technique. The UCL is commonly injured in the throwing athlete. We describe a reconstruction using semi-tendinosis allograft with humeral fixation by interference knot. 30 fresh frozen cadaveric arms were harvested and amputated at the mid-humerus. Soft tissue was stripped to the level of the elbow sparing the UCL. The native ligament was ruptured in a materials testing machine (Bionix 858, MTS) by placing a rotational torque on the humerus, with the elbow was fixed at a right angle. Load to failure and stiffness were noted. These arms were randomly assigned to be reconstructed with one of three techniques: 1. Palmaris longus allograft with docking technique humeral fixation 2. Palmaris longus allograft with interference knot humeral fixation 3. Semitendinosis allograft with interference knot humeral fixation The techniques were then tested in the materials testing machine, load to failure and stiffness were noted. Group 1: load to failure 13.31 N/m (+/− 4.2) and stiffness 19.4 N/mm. Group 2: load to failure 13.86 N/m (+/− 5.5) and stiffness 19.1 N/mm. Group 3: load to failure 20.57 (+/− 7.4) and stiffness 20.4 N/mm. The semitendinosis interference technique had a significantly higher strength (p< 0.005) but was not significantly stiffer. None of the techniques approached the strength or stiffness of the native ligament: load to failure 34.2 N/mm and stiffness 45.3N/mm. A new technique to reconstruct the UCL of the elbow uses interference knot fixation in the humeral tunnel. When a palmaris longus allograft is used this technique has a similar biomechanical profile to the established docking technique. When semi-tendinosis is used this technique is significantly stronger and may result in earlier rehabilitation in the clinical setting.
The aim of this prospective study was to report the mid-term results of arthroscopic repair of full thickness rotator cuff tears. Arthroscopic cuff repair, under regional interscalene block and balanced anaesthesia, was performed in 104 shoulders (102 patients). There were 52 female and 50 male patients with a mean age of 64 years (range 41 to 79). The mean size of the cuff tear was 3cm (range 1cm to 6 cm). Patients were discharged within 24 hours and followed a specific rehabilitation protocol. An assessment was performed pre-operatively and at a mean follow-up of 7 months (range 3 to 24 months). Outcome measures included pain, activities of daily living, shoulder function and level of patient satisfaction. Satisfactory pain relief was achieved in 98 patients (94%) with significant pain relief in 87 patients (83.6 %) and good in 12 patients (11.5 %). Ninety -six patients (92.3%) reported a satisfactory improvement in activities of daily living, with significant improvement in 89 (85.6%) and good in seven (6.7%). High levels of patient satisfaction were noted in 93 patients. Seven patients were moderately satisfied and two patients were not satisfied. The mean shoulder score improved from 29 pre-op to 82 post-op, and the shoulder function score from 32 pre-op to 84 post-op. No difference in outcome was found when the subgroup of 65 patients over the age of sixty was compared to the group of 37 patients under the age of sixty. We believe that this study has shown that the arthroscopic repair of the rotator cuff can consistently achieve a satisfactory outcome. It may therefore be considered as an alternative to the traditional open techniques.
The purpose of this study is to report our experience with revision of total elbow arthroplasty by exchange cementation. Between 1982 and 2004 at our institution, forty six elbows were treated with exchange cementation of a total elbow arthroplasty into the existing cement mantle or debrided bone interface, without the use of an osteotomy, bone graft or prosthetic augmentation. Indications for the procedure were aseptic loosening (17), second stage after septic loosening (14), instability (7), prosthetic fracture (4), periprosthetic fracture (2), failed hemiarthroplasty (1) and ulnar component wear (1). Both components were exchanged in 18 elbows, the humerus alone in 25 and the ulna in 3. Mean follow up was 90.5 months (10 to 266 months);18 patients had died with the prosthesis in situ. Complications were noted in 22 elbows; periprosthetic fracture of ulna (6) and humerus (2), humeral component fracture (1), aseptic loosening (4), non-union (1), heterotrophic ossification (2), soft tissue contracture (2) and soft tissue failure (2), delayed wound healing (1) and bushing failure (1). Reoperation was required in 10 elbows for revision of both components (2), ulna (3), humerus (1), bushing revision (2), soft tissue debridement (1) and soft tissue repair (1). There were no septic recurrences in previously infected elbows; however the reoperation rate in this group was 29% versus 19% after re-cementation for other causes. Revision of total elbow arthroplasty by exchange cementation is a reasonable treatment for those elbows with adequate bone stock for secure prosthetic fixation; however careful consideration should be given to augmentation of the ulna due to the high rate of periprosthetic fracture in this series. Re-cementation following débridement for infection is effective despite having a higher rate of revision operation compared to re-cementation in the aseptic elbow.
The purpose of the study was to determine how suture materials commonly used in arthroscopic surgery were affected by electrocautery. The effects of electrocautery were evaluated on four different suture materials commonly used in arthroscopic surgery; PDS, Ethibond, Orthocord and Fibrewire. Single suture strands were tied around two plastic rods immersed in a saline filled water bath at 37°C. Sutures were exposed to heat using the Mitek VAPR 3 electrosurgical unit and a corresponding side electrode. This was used on the high intensity vaporisation setting, at a power level of 240W. The electrode was applied directly to the suture strand, under tension, until the strand was completely burnt through. Fibrewire demonstrated a significantly higher burn through time in comparison to the other materials tested (83.30±38.69s, p< 0.001). Orthocord also demonstrated high heat tolerance (38.96±12.64s), which was significantly higher than both PDS (1.61±0.25s) and Ethibond (0.93s±0.06s) (p< 0.001). This is the first study to our knowledge assessing the tolerance of suture materials to electrocautery. This has important implications for the arthroscopic surgeon. On completion of an arthroscopic repair, the surgeon must always be extremely cautious, for fear of damaging the suture material and compromising their soft tissue repair. This study demonstrates that both Fibrewire and Orthocord can tolerate prolonged, direct heat application from electrocautery. We therefore conclude that short bursts of soft tissue vaporisation, after completing an arthroscopic repair with Fibrewire or Orthocord, are unlikely to have a detrimental effect on the suture material. However care should be exercised by the surgeon using Ethibond or PDS.
This pilot study assesses level of agreement between surface and fine wire electromyography (EMG), in order to establish if surface is as reliable as fine wire in the diagnosis and treatment of abnormal muscle patterning in the shoulder. 18 subjects (11 female, mean 36 years) with unstable shoulders were recruited after written consent and ethical approval. Anthropometric information and mean skinfold size for triceps, subscapular, biceps and suprailiac sites were obtained. Triple stud self adhesive surface electrodes (“Triode” – Thermo Scientific) were placed over Pectoralis Major (PM), Latissimus Dorsi (LD), Anterior Deltoid (AD) and Infraspinatus (IS) at standardised locations. A ‘Medi-Link’ dual channel surface EMG (Electro Medical Supplies) displayed a rectified smoothed signal. Patients performed five identical uniplanar standard movements (flexion, abduction, external rotation, extension and cross body adduction). After a rest period, a dual needle technique for fine wire insertion was used displaying a raw EMG signal on a ‘Sapphire II’ four channel EMG unit. An experienced examiner in each technique reported if muscle activation patterns differed from agreed normal during any movement and were blinded to the other test results. Sensitivity, specificity and kappa values for level of agreement between methods were calculated for each muscle according to the method of Altman. 15 patients were successfully tested. Sensitivity, specificity and kappa values between techniques for each muscles were PM (57%, 50%, 0.07), LD (38%, 85%, 0.22), AD (0%, 76%, −0.19) and IS (85%, 75%, 0.6). Only IS demonstrated high sensitivity and specificity and a moderate level of agreement between the two techniques. There was no correlation between skinfold size and agreement levels. Surface did not agree with wire analysis for PM, LD and AD, although IS did show moderate agreement. Subcutaneous fat did not appear to affect correlation.
We document intra-articular pathology in collision athletes with shoulder instability and describe the ‘collision shoulder’ – a direct impact without dislocation, with unusual labral injury, significant intra-articular pathology and neurology. 183 collision athletes were treated for labral injuries in 3 centres. Details of injury mechanism and intra-articular pathology at surgery were recorded. Premier league and International (Elite) comprised 72 players. A tackle was implicated in 52% of injuries and 65% had a dislocation. The mechanism of injury was ABduction External Rotation (ABER) in 45%, direct impact 36%, abduction only 8% and axial load 6%. Dislocation occurred in 51% of shoulders with ABER mechanism. A Bankart lesion was found in 79% of these shoulders; Hill-Sachs in 58% and Bony Bankart in 26%. Inferoposterior labral tears were present in only 11%, Superior Labral Antero-Posterior (SLAP) lesions in 32% and partial injury to the rotator cuff in 32%. In those sustaining a direct impact to the shoulder, 61% did not document dislocation, had a high incidence of inferoposterior labral involvement (50%), neurological symptoms (32%), but a low incidence of Bankart (33%), Hill-Sachs (22%) and Bony Bankart (11%) lesions. The mechanism did not affect incidence of superior labral/SLAP tears (18%), or capsular tears (including Humeral Avulsion of Glenohumeral Ligaments – HAGL) – 15%. Elite athletes had less dislocations (43% vs 74%) irrespective of mechanism, but were 40% more likely to have neurology, posteroinferior labral, cartilaginous or capsular injuries. They had twice the incidence of Bony Bankart and rotator cuff lesions and 5 times more SLAP/superior labral tears. Collision athletes with shoulder instability have a wide spectrum of pathoanatomy of the labrum and frequent associated intra-articular lesions. Significant injury often occurs in the Elite athlete and those sustaining a direct hit without dislocation (the ‘Collision Shoulder’).
We assessed a new knotless anchor system (Opus AutoCuff, ArthroCare Sports Medicine), which was designed to repair torn rotator cuffs. This knotless anchor winches cuff tissue into the bone with a mattress suture that is cinched into place without the need for knots. We reviewed patients who underwent arthroscopic repair with this technique with a minimum follow up of one year. This is prospective study of a consecutive series of the first one hundred patients who underwent arthroscopic cuff repair with the Autocuff system in 2005. Nine were lost to follow-up leaving ninety-one were available for review. All sizes of cuff tear were addressed and in all one hundred and eighty anchors were deployed. There were thirty seven men and sixty seven women with an average age of 69.4 years (range 36–85 years) Follow-up was by clinical assessment, cuff ultrasound and plain radiographs one year after surgery (12–20 months). Pain relief was described as good to excellent in 93% of patients and Constant scores improved by an average of 34 points with 48.5% being good to excellent, 39.4% fair and 12.1% poor. Nine anchors (5%) in eight patients had pulled out at one year, of which three were symptomatic. Suture repair poses varied points of weakness; loose knots, suture attrition and screw toggle all contribute to failure. We have shown that cuff repair by this method appears to be effective up to one year. It is important, however, to spread the tension of the repair with more than one anchor when treating larger tears.
The aim of this study was to understand the role tissue hypoxia and apoptosis have on a human model of rotator cuff failure. We studied twenty seven patients with no tear mild impingment (3), no tear moderate impingment (3), no tear severe impingment (3), partial tear (3), small tear (3), moderate tear (3), large tear (3), massive tear (3) and control (3). A supraspinatus tendon biopsy was taken during debridement/repair in all cases (ethics no. C01.071). Control tendon was obtained from the subscapularis tendon of patients undergoing stabilization surgery. Biopsies were analysed using two immunocytological techniques. A monoclonal antibody against BNIP-III (a marker of hypoxia) and TUNEL (Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling – an apoptotic detection process). An immunoflorescent counterstain DAPI (4′,6-diamidino-2-phenylindol) was used to stain all cells. Positive cells and total cell number were then counted in 10 high powered fields. The results showed a significant increase in BNIP-III expression in the cuff tears compared with intact tendons. This increase was least in the massive tears. Apoptosis increases from mild impingment to massive cuff tears (mean 7.3% to 21%) In conclusion, as tear size increases, the viability of the tendon reduces with increasing hypoxia and apoptosis.
The aim of the study was to prospectively review the incidence of shoulder injuries in a group of professional rugby union players and to identify any relationship between the injury and the causes, position of play, treatment and time to return to playing. An electronic database system was developed specifically to identify the objectives listed above with a view of reducing injury incidence and recurrence through identification of trends. The system was implemented in both Cardiff(2000–2003) and Llanelli(2005–2007) Rugby Football clubs. Extensive prospective data was collected by the team physiotherapists including: Type of injury(Orchard Coding), playing position, session, mechanism of injury and days lost per injury. Shoulder injuries represented 14% of all injuries sustained. Soft tissue injuries account for about 50% of the injuries and result in an average loss of five playing days. AC joint injuries ( 26%) with a recovery period of 5 days were all treated conservatively. Glenohumeral dislocations caused an average loss of 150 days and all required surgery. Fractures around the shoulder were rare with an incidence of 4%. The most common mechanism for shoulder injury was the tackle (43%). Collisions accounted for 15% of injuries whereas weight training was responsible for 31%. Contact situation training was as risky as real game situations. Back row players were more likely to sustain AC joint injuries. Surgical intervention was needed in only 11% of all shoulder injuries. Our data has shown that most shoulder injuries were from contact related areas. Physiotherapy played a key role in the rehabilitation of these players with surgery only indicated in glenohumeral dislocations and fractures. Careful planning of training sessions with emphasis on tackling and weight lifting techniques may reduce the incidence of such injuries.
Data were collected on patients undergoing subacromial decompression (SAD) in our routine practice from 1998 to 2004. All patients had clinical signs of subacromial pain and had failed conservative treatment. Tears were not repaired. Data on age, gender, arm dominance and presence of cuff tear at operation were recorded. At six months post-operatively, patients were assessed with the Constant Score (CS). Data were analysed using multiple linear regression. Data on 427 patients were collected, 168 having rotator cuff tears. The mean age was 55.41 years (SD 12.00). There were 233 women and 191 men. There were no significant gender differences between the two groups (x2=2.34, df=1, p=0.13). The group with cuff tears were significantly older by 10.24 years (p< 0.001, 8.10 to 12.38). Power of the study was 90% at the 5% significance level. Multiple linear regression showed that gender, age and presence of a cuff tear all had a significant effect on the CS. Gender B = 5.52 (1.99 to 9.06) p = 0.002 Age B = −0.31 (−0.48 to −0.15) p < 0.001 Cuff tear B = −5.51 (−9.48 to −1.55) p = 0.007 Hand dominance and the side operated upon had no significant effect. We found that in patients with symptomatic shoulders, who had failed conservative treatment and undergone an SAD, the CS at six months follow up was lower in those who had a cuff tear. There was increased tear prevalence in slightly older patients, and these scored on average 5.5 (1.5 to 9.5) points less than expected on the CS, p = 0.007, after allowing for age and gender. We believe that the surgeon should discuss with the patient whether a 5.5 points lower score is enough of a difference to warrant a formal rotator cuff repair rather than debridement and SAD alone, and a joint decision should be made.
We review our results of arthroscopic capsular plication in patients with ligamentous laxity that had developed symptoms of instability after a traumatic event. Between 2004 and 2005, 115 patients with traumatic injury to their shoulder underwent arthroscopic stabilization and repair of their shoulder. Of these, twelve patients had ligamentous laxity and had their capsule plicated as a means to stabilize their shoulder. All had failed three months of biofeedback physiotherapy. The mean age of the patients was 29 years (range 17 to 46). The average time interval between date of injury and surgery was 21 months. They were reviewed retrospectively with a minimum follow up of 2 yeats. The functional outcome was assessed by Constant scoring system and Rowe score. At arthroscopy, capsular plication with a south to north direction would be fashioned with #1 PDS sutures. In multidirectional instability, the inferior and posterior capsule would be plicated as well. If the labrum was torn, this and the capsule would be repaired together. The repair was reinforced with rotator interval closure. Postoperatively the arm was rested in sling for four weeks followed by gradual mobilization. At a minimum follow up of two years, all twelve shoulders became stable. There were 8 excellent, 3 good and one fair result as graded by modified Rowe score. Re-arthroscopy in the patient with fair result showed good capsular repair and presence of scar tissue in the subacromial space. All patients rated their shoulder as normal. Ten patients returned to their preinjury level of competitive sport. Two patients returned to sport but at a lower level voluntarily. Arthroscopic capsular plication appears to be a safe and reliable technique in stabilizing shoulders in patients with ligamentous laxity. This form of repair should be offered to this group of patients if treatment with biofeedback physiotherapy fails.
An Extended Scope Practitoner Physiotherapist (ESP) developed a problem shoulder clinic to support the physiotherapy management of patients with shoulder pathology across one healthcare trust. The impact of the clinic on the management of patients and their onward referral to a shoulder surgeon was evaluated. Physiotherapists had access to a problem shoulder clinic that was managed by an ESP with a special interest in shoulders. The clinic provided assessment and advice on the management of patients with shoulder pathology who were receiving physiotherapy treatment. Throughout a three-year period the opinion of the ESP was sought on 256 patients. 69 patients were seen in a face-to-face consultation, the remainder were diuscussed with their treating physiotherapist and advice was offered. 211 patients were managed and discharged through the physiotherapy service. The ESP referred 45 patients to the shoulder surgeon, of which 53% underwent surgery; 20% are awaiting investigations, 22% were managed with injection therapy and five per cent were discharged. The problem shoulder clinic was shown to be a valuable addition to the clinical mentoring system in physiotherapy. It proved to be an important gate-keeping mechanism between physiotherapy and consultant care as 82% of patients referred to the clinic were managed within physiotherapy. The clinic also proved to be an effective means of identifying patients requiring surgery. Of those that were referred to the shoulder surgeon only five per cent were discharged with no further intervention. A planned development as a consequence of this evaluation is a physiotherapy advocate for shoulders for each outlying hospital within the trust. The aim of this will be to strengthen communication links between the shoulder surgeon and physiotherapy departments over a wide geographic area and to facilitate prompt identification of patients in need of referral to the shoulder surgeon.
Scapular notching is of concern in reverse shoulder arthroplasty and has been suggested as a cause of glenoid loosening. Our purpose was to analyze in a large series the characteristics and the consequences of the notch and then to enlighten the causes in order to seek some solutions to avoid it. 430 consecutive patients (457 shoulders) were treated by a reverse prosthesis for various etiologies between 1991 and 2003 and analyzed for this retrospective multicenter study. Adequate evaluation of the notch was available in 337 shoulders with a follow-up of 47 months (range, 24–120 months). The notch has been diagnosed in 62% cases at the last follow-up. Intermediate reviews show that the notch is already visible within the first postoperative year in 82% of these cases. Frequency and grade extension of the notch increase significantly with follow-up (p< 0.0001) but notch, when present, is not always evolutive. At this point of follow-up, scapular notch is not correlated with clinical outcome. There is a correlation with humeral radiolucent lines, particularly in metaphyseal zones (p=0.005) and with glenoid radiolucent lines around the fixation screws (p=0.006). Significant preoperative factors are: cuff tear arthropathy (p=0.0004), muscular fatty infiltration of infraspinatus (p=0.01), narrowing of acromio-humeral distance (p< 0.0001) and superior erosion of the glenoid (p=0.006). It was more frequent with superolateral approach than with deltopectoral approach (p< 0.0001) and with standard cup than with lateralized cup (p=0.02). We conclude that scapular notching is frequent, early and sometimes evolutive but not unavoidable. Preoperative superior glenoid erosion is significantly associated with a scapular notch, possibly due to the surgical tendency to position the baseplate with superior tilt and/or in high position which has been demonstrated to be an impingement factor. Preoperative radiographic planning and adapted glenoid preparation are of concern.
Surgical options in the treatment of acute acromio-clavicular joint (Rockwood Type III and IV) dislocations are many and controversial. We evaluated our technique using TIGHTROPE connecting the base of the coracoid to the proximal fragment of the clavicle. Between March 2006 and December 2006, ten young and active adult patients with acute ACJ dislocations were treated with arthroscopically assisted ARTHREX TIGHTROPE fixation. The dislocation was reduced with traction and manual reduction with the patient in beach-chair position. The base of the coracoid was identified and isolated using a radiofrequency ablator placed through the anterior portal while visualizing through the lateral portal. An ACL guide was placed percutaneously supero-medial to the coracoid over the distal with the inferior end of the ACL guide placed through a posterior portal, approximated against the prepared base of the coracoid. The Arthrex Tightrope braided fibre-wire was introduced through the pre-drilled distal clavicle passed to the base of the coracoid and manually tensioned to achieve stable reduction. Standard rehabilitation protocol was utilised as for internal fixation of distal clavicular fractures. Patients were evaluated clinically using Constant Score, which ranged from 75 to 83 and radiologically at 6 weeks and 3 months. We present the functional results and the technical difficulties faced highlighting on the probable reasons for failure of fixation in two of our early patients who had revision fixations. We also describe the additional intra-operative techniques used in the last few patients to prevent such complications and achieve a secure reduction. We conclude that Arthroscopic Reconstruction of dislocated Acromio-Clavicular joint using TIGHTROPE may require additional repair of the ligaments in carefully selected patients to prevent failure of fixation.
We present a retrospective analysis of 50 cases of cuff tear arthropathy, treated over a seven year period by use of reverse geometry shoulder prosthesis. 98% follow-up was achieved with average follow up of 3 years. Mean (SD) age was 81.3 (9.2) years and female to male ratio was 5:1. Six patients had bilateral reverse geometry shoulder replacements. Patients were assessed with pre-operative American Shoulder and Elbow Score (pre-op ASES) and post-operative American Shoulder and Elbow Scores (post-op ASES), Oxford, Constant and SF36 scores. Mean pre-op ASES was 22.29 (95%CI: 9.1 – 37.9) and post-op ASES score was 65.2 (95%CI: 48.5 – 81.9), (P< 0.001, Paired t-test). Mean post operative Oxford score was 27.25 (95% CI: 18.4 – 27.6). Mean post operative Constant score was 63.2 (95% CI: 52.6 – 79.6). X-ray review was performed to assess scapular notching and Sirveaux score was used to grade extent of notching. 11 patients had Sirveaux grade 0, 5 had grade 1, 6 had grade 2, 12 had grade 3 and 8 had grade 4 notching. Intra-operative complications included 2 glenoid fractures. Post-operative complications included 2 acromion fractures and 2 episodes of subsidence with dislocation. None of the patients developed post operative haematoma. There was one episode of infection in one patient that required further surgery. Iteration of approach with increasing experience over the years will be discussed. Ours is the biggest series of reverse geometry prosthesis used for irreparable rotator cuff tear arthropathy published so far in the literature and our results have shown superior results in terms of improvement in function and complications. We recommend reverse geometry shoulder replacement is the way forward to treat irreparable cuff tear arthropathy of shoulder.
Shoulder instability is a common cause of morbidity amongst Professional Rugby Union players. This study explores whether the risk of shoulder dislocation is associated with innate shoulder laxity. A prospective, randomised controlled study was completed in which all the Premiership Rugby Clubs in England were visited. 169 professional rugby players with no history of instability in either shoulder and 46 players with one shoulder with clinical instability symptoms were assessed. Shoulder laxity was measured by clinical evaluation, questionnaires and ultrasound. Anterior, posterior and inferior translation was measured in both shoulders for healthy players and the uninjured shoulder only for injured players. The results showed there was no significant difference between the left (anterior: mean 2.92 +/− 1.15 mm; posterior: mean 5.10 +/− 1.75 mm; inferior: mean 3.08 +/− 1.00 mm) and right (anterior: mean 3.07 +/− 1.14 mm; posterior: mean 4.87 +/− 1.61 mm; inferior: mean 2.91 +/− 0.99 mm) shoulders in healthy players (P > 0.05). The comparison between healthy shoulders (anterior: mean 3.00 +/− 1.15 mm; posterior: mean 4.99 +/− 1.68 mm; inferior: mean 3.00 +/− 1.00 mm) from healthy players and the uninjured shoulder (anterior: mean 4.16 +/− 1.70 mm; posterior: mean 6.16 +/− 3.04 mm; inferior: mean 3.42 +/− 1.18 mm) from injured players identified that players with unstable shoulders have a significantly higher shoulder translation in their normal shoulder than healthy players (P < 0.05). This is the first study looking at laxity and the risk of shoulder dislocations in sportsmen involved in a high contact sport. These results support the hypothesis that rugby players with “lax” shoulders are more likely to sustain a dislocation or subluxation injury to one of these lax shoulders in their sport.
To compare the effectivity of arthroscopic and open stabilisation of the shoulder. Between 2003 and 2006, 100 patients (20 female, 80 male; mean age 32 years) undergoing glenohumeral stabilisation were followed prospectively. 28 were open (3 female, 25 male; mean age 30.7 years), 72 arthroscopic (17 female, 55 male; mean age 32.0 years). Assessments were made using the Constant, DASH, and Carter-Rowe (CR) scores, as well as the Oxford Shoulder Instability Questionnaire (OSIQ) pre-operatively, at three and six post-operative months, and six-monthly thereafter. The student’s t test was used to compare the mean scores at each time point. Correlation coefficients (Pearson’s) were used to compare the postoperative course with either intervention. In general the open group performed marginally less well than did the arthroscopic. However, the DASH score demonstrated less consistency both in this relationship, and the rate of post-operative recovery when compared with the other scoring systems. In the open surgery group the DASH revealed a deterioration from the pre-operative score at six months before subsequent improvement; in the arthroscopic group, this deterioration occurred at three months. However, these differences were not statistically significant regardless of the assessment tool employed. Strong correlation was demonstrated between the rates of recovery following either surgery (Constant r=0.99; OSIQ r=1.00; CR r=0.94). Again, this was not supported by the DASH (r= −0.868). The rates of improvement were identical with either treatment when measured with the Constant, OSIQ, and CR, whilst the DASH score yielded inconsistent results. No significant difference could be shown between open and arthroscopic surgery at any individual time point regardless of the assessment tool employed. We suggest that open and arthroscopic surgeries yield very similar outcomes.
Research in to tendon-bone healing techniques focus on increasing bone growth at the interface such as cell or growth factor (e.g. BMP-2) augmentation. Demineralised bone matrix (DBM) is osseoinductive and is in use clinically.
To investigate the comparability of subjective and objective scores of shoulder function following surgery for rotator cuff pathology. From 2003 to 2006, 333 patients undergoing surgery for rotator cuff disorders were followed prospectively. 220 (66%) underwent solely subacromial decompression, whilst 113 (34%) had additional rotator cuff repair (92 arthroscopic; 21 mini-open). Assessments were made pre-operatively and six-monthly thereafter using the DASH score; Oxford Shoulder Questionnaire (OSQ); and Constant score, which was used as a reference. Standardisation calculations were used to convert all scores to a 0 to 100 scale (100 representing a normal shoulder). The student’s t test was used to compare the mean score for each subjective tool (DASH and OSQ) with the objective score (Constant). Correlation coefficients (Pearson’s) were used to analyse the post-operative course measured with subjective and objective tools for each intervention. Each statistical test was used for all surgeries collectively and the individual surgery types. There was no difference between the mean DASH and Constant scores. A significant difference was seen between the Oxford and Constant scores for at least one time point in each treatment group. Strong correlation was demonstrated between both subjective scores and the Constant. The mean Pearson correlation coefficient comparing the DASH and Constant was 0.96, whilst that for the Oxford and Constant was 0.89. The DASH and Constant scores provided identical results in terms of absolute values at a given time point, and with respect to rates of recovery. The relationship between the Oxford and Constant was less robust. In this study the DASH and Constant scores were indistinguishable, justifying the use of only the former for follow-up, obviating the need for a trained investigator required to perform a Constant score.
The aim of this study was to compare the results of physical examination and magnetic resonance arthrography (MRA) in the diagnosis of superior labrum anterior posterior (SLAP) lesions of the shoulder. A review of all patients seen in 2005–2006 with an arthroscopically confirmed SLAP lesion was undertaken (n =22). Prior to surgery all patients had been examined prospectively by an upper limb physiotherapy practitioner and had then undergone MRA. All scans were undertaken and reported upon by an experienced consultant radiologist, specialising in musculo-skeletal conditions. A combination of 4 clinical tests were used to diagnose a SLAP lesion, these being O’Brien’s, pain provocation, bicep load and the crank test. To confirm a SLAP lesion a minimum of 2 of the above tests had to be positive. The sensitivity of each test in isolation and in combination and MRA sensitivity was determined and values statistically analysed for significance. The sensitivity of each isolated test was as follows: O’Brien’s = 82%, pain provocation = 86%, bicep load = 55% and the crank test = 68%. Using a combination of 2 or more positive tests was 95% sensitive, whereas MRA had a sensitivity of 64%. Using the McNemar test there was a statistically significant assosciation between positive clinical testing and negative MRA findings in the same patient (p< 0.05). The results would suggest that it may be advantageous to use a combination of physical tests rather than 1 test in isolation when examining a patient with a suspected SLAP lesion. The study would also suggest that even in the absence of radiological findings, in patients with a relevant history and strongly positive clinical signs, arthroscopic assessment may be indicated.
Introduced in 2005, the Opus Magnum (Arthrocare) anchor has been used in our unit for repair of rotator cuff tears. It is a non-screw type anchor which relies on the deployment of wings locked in the subchondral bone. In order to evaluate whether these anchors migrate after implantation we undertook radiographic examination of their placement at intervals. We attempted to assess whether loss of fixation could be secondary to osteoporosis. Between 2005 and 2006, 106 patients (59 female, 47 male) aged 35–84 years (average age 62 years) underwent arthroscopic repair of rotator cuff tears with a total of 229 anchors. A review of radiographs taken at six weeks and 12 months post-insertion was undertaken. Cortical index of the proximal humeral diaphysis was measured from the AP radiograph indicating bone density; this involved measuring humeral width and medullary cavity diameter at a fixed point of 10cm below the greater tuberosity of the humerus. At six weeks follow-up there were no anchor pull-outs seen on radiographs. At 12 months follow-up 10 of the 229 anchors were found to have pulled out of the bone, equating to a failure rate of 4%. Of these seven of the 10 patients were asymptomatic. The average cortical index was found to be significantly lower in the failure group. Bone quality at the greater tuberosity of the humerus can be insufficient to withstand the tensions developed in newer anchor technology, leading to anchor migration. We present evidence that radiographs may be sufficient to influence the clinician’s choice of anchorage device. An economic estimation of bone density would be a helpful predictor of pull-out strength of suture anchors, essentially a low cortical index would indicate that these anchors are more likely to fail. A routine radiograph at 12 months would also identify the asymptomatic anchor failures.
The samples were treated in an air circulating oven at 90°C. Every 20 hours they were analyzed with FTIR and the carbonyl concentration was recorded.
The CL-imaging measurements were run at 180°C under oxygen in a Differential Scanning Calorimetry (DSC) coupled to a CCD camera. The Oxidation Induction Time (OIT) has been measured as the starting time of oxidation, extrapolated from the CL curve in the function of time.
The ability of α-tocopherol as a free radicals scavenger during gamma irradiation prevents the reaction of polymer radicals with oxygen. While performing this role, α-tocopherol is consumed and transformed into a variety of by-products. Nevertheless, higher OIT for the doped and irradiated specimens compared to the control (0% Vit.E, 0 kGy) suggest even a stabilising effect of these by-products.
Tension: SCF_T-Type1=4.8; SCF_T-Type2=3.2; SCF_ T-Type3=11.7; Bending: SCF_B-Type1=2.45; SCF_B-Type2=1.44; SCF_B-Type3=2.52.
In particular, spontaneous calcium phosphate deposition on titanium surfaces from aqueous electrolyte containing calcium and phosphate ions, such as simulated body fluid solutions, has been observed and is believed to be related to the excellent bonding capability in contact with bone tissue.
In the present study, a new multiphase anodic spark deposition (ASD) method combined with chemical etching is presented It has been optimized and such modified titanium surface exhibited high mineralisation potential, selective protein adsorption, quicker and more intensive osteoblasts adhesion and differentiation. Such treatements was labelled BioSpark™ and consisted in a thick calcium-phosphate-doped oxide film growth on the titanium bulk. This oxide layer exhibits anatase lattice, micro-porosity and a thin nano-roughened texture.
Follow-up MRI images revealed normal healing process, without signs of osteolysis or wear. No synovial joint reaction has been observed, but one case of implant’s dislocation occurred.
Inclusion-exclusion criteria:
anterior instability (confirmed intraoperatively by an isolated ACL tear), surgery performed within 3 weeks from injury . No grade 4 chondral defect, no associated pathologies except for meniscal lesion will to undergo to the same rehabilitation protocol.
Parameters analyzed included the standard knee scales (IKDC, Noyes, Lysholm and Tegner), SANE Score, Knee Laxity Analysis and Deep Flexion Tests. In 6 cases, second look arthroscopy was performed. All patients underwent a post-operative MRI.
In the group A the patients had an accelerated postop. rehabilitation. The group B received a standard rehabilitation protocol. Each group has been evaluated prospectively with VAS, UCLA and Constant scores pre-op and during follow-up.
The VAS score of group A (PDGF) was pre-op. 5.6 and at 1 year 1.4. The VAS score of group B (no PDGF) was pre-op. 5.2 and at 1 year 1.4. The UCLA score of group A was pre-op. 16 and at 1 year 33.8. The UCLA score of group B was pre-op. 16.7 and at 1 year 32.9. The Constant score of group A was pre-op. 53 and at 1 year 90.7. The Constant score of group B was pre-op. 54.2 and at 1 year 90.1.
The complete statistical analysis of the data showed no significant differences in the results of the two groups (p< 0,01), with every kind of scores, VAS, UCLA and Constant, at the final follow-up of 1 year.
(a) To choose the tendon grafts considering the donors’ characters; (b) To use fresh tendons; (c) To test the controlateral tendon from the same donor before use.
Delayed union of the docking point in pseudoarthrosis of long bones treated with the Ilizarov technique (resection and distractional osteogenesis) and traditional techniques (decortication and fresh bone autograft) not suitable for application. The treatment of a pseudoartrhosis is based on our classification in type: I, II, III, IV (septic). Traditional techniques failure. Choice first treatment in very difficult cases of limb reconstruction and bone nonunion.
In this study BMPs/AGFs were used in posttraumatic long bone non-union and osseous defects to test their clinical and radiological effectiveness in order to find a valid alternative to autologous bone grafting.
Moreover, the overall recruitment period is 3 years during which 40 patients/year will be enrolled up to a total of 120 cases; half of these will be treated with rhBMP-7 and the other half with PRP.
We investigated voluntary control recovery after termino-lateral neurorrhaphy in the upper limb of mixed rat nerves (median and ulnar nerves) to assess functional recovery and nerve fibers regeneration.
On microscope median nerve presented the typical structure of a regenerated nerve; in ulnar nerve some slight signs of degeneration can be detected distally to the site of suture. At the point of suture, nerve fibers of ulnar nerve sprouts into median nerve (collateral sprouting).
In the donor ulnar nerve distally to the suture site we found some slight signs of damage, but they do not impair motor function.
In conclusion, termino-lateral neurorrhaphy can be used to repair peripheral nerve lesions with large substance loss where other types of repair strategies cannot be attempted.
Primary human fibroblasts were seeded on collagen I membranes with aligned fibres (# 40133) with and randomly arranged fibres (# 40153). Cell proliferation was evaluated at 4, 8 and 12 days by spectrophotometry. Membrane sections were studied by immunohistochemistry and by confocal microscope on day 12 of culture.
The middle third of the patellar tendon was lesioned bilaterally in 10 adult male New Zealand White rabbits and repaired on the right side by a graft (# 40133). The contralateral tendon was left untreated and served as control. Animals were euthanized 1 or 6 months after surgery and the tendon grafts subjected to histological examination.
Cells were homogeneously distributed, with a more marked orientation along the main membrane axis in batch 40133 than in 40153. The in vivo study showed that cell orientation and differentiation in the scaffold with aligned fibres was satisfactory, with decreased cellularity, good integration with the surrounding tissue and crimp formation. Inflammatory reaction or excessive implant neovascularization were never observed.
5 peroneal vincula biopsies were analyzed from patients affected by ankle instability and undergoing tendoscopy for peroneal tenosynovitis.
Degenerative changes were more evident on the articular side of the rotator cuff.
Surgical approach with percutaneous indirect articular reduction by elevating,minimal osteosynthesis and the use of NORIAN Skeletal Repair System lets us reach three fundamental objectives stated before.
NORIAN S.R.S, used to fill the bone gap resulting from the traumatic collapse of the metaphyseal bone, with its mechanical strength allows the stabilization of the joint fragments, the reduction and the relative ostheosyntesis, thus greatly shortening the functional recovery time.
The minimum follow-up was 1 year. We used for clinical evaluation the Hohl assessment form, for the radiographs the criteria of Rasmussen.
Mobilization is allowed the day after surgery and weight-bearing within the first week in B2 e B3 fracture type and within four weeks in C3 type reducing to the minimum knee posthraumatic stiffness.
The statistical analysis of the data shows a direct correlation between anxiety level and pain perception in the pre surgical period. Furthermore, patients with higher level of anxiety showed an increased use of analgesic drugs in the post surgical period (the higher dosage prescribed on demand). The unpleasant memory persistence is however mitigated in the same group, possibly due to much drug assumption.
The length of the graft was divided into three zones : zone 3 the femoral neck; zone 2 the lower femoral head or “metaphysis”; zone 1 the more apical or epiphyseal component of the femoral head. The intention was to follow the vascularization of the pedicle and the changes in the three diverse areas of the specimen. The graft showed incorporation with the host bone. In the pedicle there was preservation of vascular patency and tissue viability.
The broad interest of this study was addressed to the mechanisms which control the structural modelling of cortical bone in the course of the long growth and development, therefore a morphometric evaluation appeared the more suitable method for the possibility to examine large segments of the bone.
Ditigital microscope images were analyzed utilizing the software Cell D: the cortical area was measured and the number of vascular canals was counted and expressed as a function of the cortical area (n/mm2). The total cortical area, the density of vascular canals and the frequency distribution for area classes in the cortex of mid-shaft and distal-shaft was compared with paired student t test and Pearson chi-square test respectively.
In this study, we hypothesized that high pressure processing of PE would be advantageous if it is performed only after irradiation and quenching of free radicals and that it would be detrimental if it preceded irradiation. We used accelerated oxidation, mechanical tests and wear tests to show
During the last 15 years we have had the opportunity of analysing more than 700 UHMWPE prosthetic components (hip, knee and shoulder). Among them, about 500 were retrieved during revision surgery, while the remaining were new, ready-to implant, variably shelf-aged samples. The analysis of such a large, representative sample provided several important insights into the variables which influence the behaviour of UHMWPE in vivo; moreover, a long period of observation gave us the opportunity to follow changes and improvements in the field over time. All samples dated back to the nineties or before and sterilized with high energy radiation, either shelf-aged or retrieved, showed variable, but generally high, oxidation levels. Starting from the observation of these samples and with the aid of specimens irradiated on purpose under controlled conditions, some improvement has been achieved in the knowledge of radiation-induced oxidation process. The importance of the determination of hydroperoxides on the oxidation potential has been highlighted and the influence of variables such as sterilisation atmosphere, packaging, temperature and dose rate on the oxidation process has been clarified. The need for a suitable stabilizer to minimize oxidation arises during these studies.
We also had the opportunity of analysing a large number of EtO-sterilised samples, both new and retrieved. A small amount of them, all manufactured in the nineties, showed some bulk-oxidation which has been related to the presence of calcium stearate into the pristine resin. None of the newly produced, calcium stearate-free samples showed any oxidation and this group allowed to explore the behaviour of undegraded UHMWPE in vivo and in the shelf. Diffusion of polar compounds from the synovial fluid into polyethylene was observed in the majority of the retrieved samples. The nature of these products have been investigated along with their possible influence on the mechanical properties of the polymer.
In the last five years, we had the opportunity to study a significant number of crosslinked polyethylenes, both new and retrieved. The results of this study indicate that the variables of the crosslinking process can greatly influence final material properties and that not all cross-linked polyethylenes are the same.
The optimal clinical and x-ray results, even if they are at short term, considered as indices of a good osteointe-gration, push us to believe that the use of the tantalum tibial plateau could be a good solution for any young patient with a gonarthrosis
The authors selected for the study young-middle age active patients, with incomplete ACL lesion: 27 patients (mean age of 23 years) have been evaluated, inclusion criteria was Lachman test < 1 cm, negative Jerk test and a proximal partial tear of ACL on MRI. Before and after surgery the patients have been evaluated using KT1000, MRI, clinical examination and Lysholm score with a 3 years average follow up.
We assigned them retrospectively to one of the two groups: Group 1 underwent arthroscopic repair of the rotator cuff and repair of the type II SLAP lesion. Group 2 underwent arthoscopic repair of the rotator cuff tear and a tenotomy of the long head of the biceps.
Authors present their experience with different surgical methods.
The choice of surgery depends on the age of the growing child and on the site of the neoplasm.
Females were eight and males were five. After ten years only ten patients were disease free (seven osteogenic sarcomas and three Ewing’s sarcomas).
In five cases of o.s. the age of the patients was over fourteen years, the remaining growing period was limited and for this reason a mechanical growing prosthesis was employed.
In the four cases of diaphyseal Ewing’s sarcoma the reconstruction was performed in two cases employing an autologous graft taken from the iliac crest and in two cases a microvascularized fibular graft.
Functional results of the affected limb, in the surviving patients, depend on the sacrifice of the joint (arthro-dhesis) or in the use of a modular prosthesis that, in AA. experience have a follow-up of 12 years; in diaphyseal reconstruction an anatomical result was obtained either with the mcrovascularized fibular graft or with the autologous graft from the iliac crest, the only difference between these two methods depending on the time of bone healing.
The aim of this study was to describe the development of disc related MRI-findings in patients with sciatica treated conservatively using a validated evaluation protocol.
Three percent of bulges and 38% of focal protrusions improved, whereas 75 – 100% of the more substantial herniations, i.e. broad-based, extrusions, and sequestrations improved (p< 0.0001). Improvement over time for nerve root compromise was seen in 60% of the cases. Disc signal, disc height, and HIZ remained unchanged in 63–73%. Treatment and age groups did not show any differences. However, gender differences were found in relation to baseline findings and development over time.
Data shows that women with pain have higher scores than men with pain on all scales, except for expressing emotion. Differences on palliative behaviour, avoidant behaviour, social support and comforting cognitions are significant (p < .001).
Back pain/neck pain was the presenting complaint in 100% whereas neurological signs were found in 37% and systemic manifestations present in 38%. To control the disease, spinal surgical procedures was needed in 44% of cases. Approximately 30% of them had partial recovery and 9% had complete recovery.
The study was founded by The Regional Institute of Health Sciences Research
Clinically useful improvements of greater than 10 points on the ODI occurred in 54%, deterioration of 10 points or more occurred in 17%. Visual analogue for leg improved by 2 or more in 63%.
There was no statistically significant difference between the groups at 3 months (change in ODI [p=0.2], change in VAS [back pain, p=0.28; leg pain, p=0.67]. Subgroup analysis revealed no statistically significant difference in the change in scores between the stenotic group and disc herniation group at 3 months. At 1 year follow-up data was available for 86% of the patients. There was no statistically significant difference in the rate of further interventions.
The aim was to evaluate the efficacy of two active conservative treatment programs to patients with severe sciatica.
In both groups treatment consisted of thorough Information concerning anatomy, pathogenesis, how discs heal without surgery, and Advice and encouragement to stay as active as possible, and optional medication. Then either Symptom guided exercises or Sham exercises.
The aim was to evaluate a possible effect of antibiotic treatment in an uncontrolled group of patients with LBP and Modic changes.
The aim of the study was to assess the effectiveness of surgical treatment for degenerative lumbar spinal stenosis (LSS) as compared with non-operative measures. Four university hospitals contributed, after agreement on study protocol, surgical rationale and non-operative procedures (For details, see
We conclude that surgical treatment improves functional ability in lumbar spinal stenosis. We emphasize that improvement also occurs after nonoperative measures. We recommend starting treatment with non-operative measures during a 2-year surveillance period, as during this period only 10 per cent of the patients will need surgical intervention.
Multiple treatments of Sacro-iliac joint (SIJ) dysfunction have been adopted by various disciplines that treat low back pain. The aim of this audit is to evaluate the effect of steroids and Local anaesthetic injection (LA) in the management of SIJ dysfunction and to determine the relation between road traffic accident and low back pain (LBP).
We retrospectively reviewed 31 patients who were diagnosed as having SIJ dysfunction. All patients had steroids and LA injection under x-ray control. Based on previous history of road traffic accident patients were divided into RTA and non-RTA group. Through a postal questionnaire the severity of LBP and leg pain (pre and post injection) were assessed using visual analogue scale (VAS). Functional level was evaluated through the Oswestery disability Index (ODI).
All patients showed improvements in LBP and leg pain post injection with mean improvement in VAS of 2.95 (SD 3.0, p-value < .0001) for LBP and mean improvement of 3.3 (SD 3.3, p-value < 0.001) for leg pain. Similarly the ODI showed mean improvement of 15.0 (SD 17.0, p-value < 0.0001). Patients in the RTA group showed greater improvement than the non RTA group, however this did not reach statistical significance.
We conclude that steroids and LA injection is an effective method in management of SIJ dysfunction. Also our study suggests that RTA can be a potential cause of back pain by causing SIJ dysfunction. We accept that our sample size is small and needed to be confirmed through a prospective randomised controlled trial which is currently taking place in our institution.
Patients’ who had consulted both mainstream and CAM practitioners reported the poorest health outcomes (EQ 5D = 0.55), followed by those who consulted just mainstream practitioners (EQ 5D = 0.61), and those who had consulted no one (EQ 5D = 0.72). The best health outcomes were reported amongst those who had just consulted CAM practitioners (EQ 5D =0.78). In multivariate analyses, the most powerful predictors of consulting both mainstream and CAM practitioners were working and having high levels of pain related disability.
Dysfunction of the pelvic girdle causes alteration of the lumbopelvic muscle supporting function and thus disruption of the load transference through the pelvis.
Walking loads symmetrically the muscles that provide stability to the pelvis for load transference and is an easy way to evaluate bilateral muscle function.
The aim of this study was to find out if mobilisation of the symptomatic sacroiliac joint (SIJ) in chronic low back pain patients could alter the lumbopelvic muscle activity measured by surface EMG (sEMG) on the symptomatic side during walking.
The resulting change in the muscle activity seemed to be relaxation of the muscles evaluated.
The muscles whose activity changed for the most during walking after mobilization of the symptomatic SIJ were biceps femoris, on the right side 17,8% (p= 0.007) and on the left side 12.8% (p= 0.012). The right gluteus medius relaxed 14.4% (p=0.016) and left side 6.1% (p=0.033). Lumbar multifidi reacted more on the right side 14.5% (p=0.003) and on the left the decrease was 8.3% (p=0.021). Oblique abdominal externus muscles showed very little change after intervention.
This study gives us the point of view that the main influence the mobilisation has on SIJ is neurophysiological, reflectoric on muscle tone.
The mean duration of surgery was 4 hours 19mins. The results for operation duration < 5hours vs. operation duration > 5hours (3/96 vs 6/51) were not statistically significant. (p=0.065)
Of the 147 instrumented spinal operations, 8 of the infected were performed in a laminar air flow system and 1 without (not statistically significant, p=0.69).
The results for blood transfusion < 2units vs. blood transfusion ≥2 units (4/85 vs 5/62) were not significant (P=0.49).
SSI in spinal surgery was heavily influenced by instrumentation, but was not reduced by laminar airflow. Duration of operation and number of units of blood transfused were not significant factors.
Outcome assessment revealed significant improvement in SF36 even after removal of stabilising system while no worsening of ODI or VAS in comparison with preoperative status.
No correlation between within individual change in load and presence or absence of LFP was found. Only one subject showed a significant correlation between individual change in load with the magnitude of LFPs (r=−0.75, p=0.012). However, when the cumulative data from all 19 subjects was analysed, small correlation between the change in load and magnitude of LFPs (r=−0.17, n=187, p=0.022) was observed, with greater load associated with smaller LFP. No other correlation between gender, individuals load, age and fitness was found.
Question:
This data suggests that there is a low but significant number of patients who attend twice. Although advice is to increase activity this is not always demonstrated so how had their understanding been evaluated. Why are some GP’s referring patients back with the same diagnosis?
Abbreviated Measured Vertical Traction (Abbr.M.V.T.) allayed the symptoms of patients showing contained disc herniation, degenerative spondylolisthesis, disc resorption(
The submitted patient with congenital spinal stenosis had chronic bizarre symptoms and neurologic signs disabling him. In 2/04/1998 was treated by Abbr.M.V.T. Sudden relief and unexpected recession in his symptoms was reported immediately post-traction, allowing free activity. Symptoms receded soon after, disappearing in a few months and since then never until now disturbed him.
Structural features and venous hypertension are the causes of symptoms in patients with spinal congenital stenosis (
The post-traction cessation of symptoms would suggest missing venous hypertension. Does that mean that Abbr. M.V.T. had extinguished venous hypertension? This is an hypothesis, because reduction of the hypertension seems a weak possibility in view of a disturbed venous anatomy of the root canal (
Evolvements indicate a more likely hypothesis would be to attribute the cessation of pain to the exchange of fluids occurring during Abbr.M.V.T. (
Sarcoidosis is a multisystem syndrome characterized by the development of non-caseating granulomata. The lesion disrupts the architecture and function of the tissue in which they reside.
Sarcoidosis in and around the spine is very rare affecting less than 1% of patients with the disease. It can affect various parts of the craniospinal axis: intramedullary, intradural, extramedullary, intraspinal epidural spaces and in vertebral bodies. In this report we present a rare case of sarcoidosis in the intervertebral disc causing diagnostic dilemma. To our knowledge this has never been reported before.
Our patient has had aggressive systemic sracoidosis, however the first presentation of the disease was in his spine in the form of intractable low back and leg pain resistant to treatment. X-ray and MRI showed Listhesis at L4/5. Posterior Fusion was performed. Pain became worse and accordingly anterior fusion was attempted, which was aborted because of excessive bleeding. Patient then developed subcutaneous nodules. Biopsy from the nodules showed features of non-caseating granulomatous lesion. In view of the persistence of his symptoms biopsy from L4/5 disc was performed and showed similar histological features. CT chest and abdomen confirmed the diagnosis of sarcoidosis. The patient was commenced on steroids and Methotrexate.
In this report we highlight the approach to diagnosis and management and present a review of the literature. Our main aim is to make the clinicians more aware of this rare condition and raise the index of suspicion, particularly if the first presentation of this multi-system granulomatous disorder is in the spine.
Randomised controlled trials (RCTs) of non-specific low back pain (LBP) interventions commonly estimate sizes of treatment effect from subjective scales. It is not clear which scales are most commonly used. Moreover, the standardized effect sizes, d, of interventions are typically small (d ≈0.3) and many trials may be underpowered to detect d at this magnitude, regardless of scale used. We identified RCTs reported between 1980 and 2000 from the European guidelines for low back and extended the search to 2006 using MEDLINE, EMBASE, PsycINFO, Cochrane, and Lilacs. We extracted data from identified studies concerning outcome measure use and power to detect d. Following analysis of 222 papers, the most commonly used outcome measure was the visual analogue pain scale (VAS-P), used by 42% of trials, followed by the Roland Morris disability questionnaire (RMDQ), used by 34% of trials. Secondary measure use was diverse; 5% of trials included 10 or more measures and 40% involved at least one objective measure. 57% of the trials were powered to detect d = 0.8, only 37% could detect d = 0.5, only 6% were able to detect d = 0.3 and only one trial could detect Cohen’s definition of a small effect, d = 0.2. In sum, the VAS-P is the most commonly used outcome measure in trials of non-specific LBP and the majority of trials are too small to show effect sizes that might realistically occur.
Since neurological claudication is a major symptom in lumbar spinal stenosis (LSS), walking distance is commonly used as a measure of the severity and surgical outcome in LSS. The aim of this study was to compare self-reported and treadmill-measured walking distances in a trial, in which 94 patients with moderate LSS had been randomized into conservative and surgical treatment. Among the 44 patients in conservative treatment, the treadmill-measured walking distance was more reproducible after 6 months than the self-reported distance; the intraclass correlation coefficients were 0.75 and 0.41, respectively. Among all the patients at baseline, the agreement between self-reported and measured walking distance was satisfactory (intraclass correlation 0.57), although male patients overwhelmed their performance by 200 meters. Such a shift was not found in women. For walking distance categorized as < 400, 400–1249 and ≥ 1250 meters, there was a fair agreement between self-report and treadmill (weighed kappa 0.42). However, when the analysis was restricted to those whose walking distance was restricted to < 1250 meters, the corresponding agreement was poor (intraclass correlation 0.26). The self-reported walking distance was closely correlated with Oswestry index at baseline (r = 0.26), and changes in these outcomes from randomization to the follow-up of 6 months showed a strong correlation with each other (r = 0.37). We conclude that walking distance is a fundamental element of disability in LSS. Self-reported walking distance seems to be an appropriate clinical tool, but its limited precision in relation to treadmill-measured distance must be considered, when walking ability is severely restricted.
Relationships among the variables were measured by means of Pearson correlation coefficients.
Impaction bone grafting with morsellised allograft is a recognized technique to reconstitute loss of bone stock often encountered during revision hip surgery. Concerns over disease transmission, high costs and limited supply has led to interest in synthetic grafts. Poly (lactic acid) (PLA) grafts are attractive to the tissue engineering community as a consequence of their biocompatibility, ease of processing into three-dimensional structures, their established safety as suture materials and the versatility that they offer for producing chemically defined substrates for bone graft matrices. This study set out to examine the potential of PLA scaffolds augmented with human bone marrow stromal cells in impaction bone grafting (IBG).
Quantification and 3D visualization of new vessel networks in vivo remains a major unresolved issue in tissue engineering constructs. This study has examined the potential of combining the use of a radio opaque dye and micro-CT to visualize and quantify microvascular networks in 3D in vivo. We have applied this technique to the study of neoangiogenesis in a bone impaction graft model in vivo as proof of concept. Tissue engineered constructs were created with natural (morsellised allograft) and synthetic grafts (Poly Lactic Acid, PLA)
Culture expanded human bone marrow stromal cells (HBMSC) labeled with a fluorescent probe (Cell Tracker Green, CTG) to measure cell viability, were seeded onto prepared scaffolds (morsellised allograft or PLA) and impacted with a force equivalent to a standard femoral impaction (474J/m2). The impacted HBMSC / scaffolds and scaffolds alone were contained within capsules and implanted subcutaneously into severely compromised immunodeficient mice. Radiopaque dye was infused into all vessels via cardiac cannulation prior to removal of implants. Micro CT imaging and immunohistochemistry was performed in all samples.
Cell survival was evident by abundant fluorescent staining. The average number of blood vessels penetrating the capsules were 16.33 in the allograft / HBMSC constructs compared to 3.5 (p=0.001) in the allograft alone samples and 32.67 in the PLA / HBMSC constructs compared to 7.67 (p=0.001) in the PLA alone samples. The average total vessel volume within the capsules was 0.43mm3 in the allograft / HBMSC constructs compared to 0.04mm3 (p=0.05) in the allograft alone samples and 1.19mm3 in the PLA / HBMSC constructs compared to 0.12mm3 (p=0.004) in the PLA alone samples. Extensive staining for Type 1 Collagen, new matrix and Von Willebrand factor in living tissue engineered constructs confirmed osteogenic cell phenotype, and new blood vessel formation respectively.
In summary, these studies demonstrate, HBMSC combined with either morsellised allograft or PLA can survive the forces of femoral impaction, differentiate along the osteogenic lineage and promote neovascularisation in vivo. Successful combined neovascularisation and bone formation in impacted tissue engineered constructs in vivo augers well for their potential use in IBG.
This novel technique utilising contrast enhanced 3D reconstructions in combination with immunohistochemistry enables quantification of neovascularisation and new bone formation in impacted tissue engineered constructs with widespread experimental application in regenerative medicine and tissue engineering analysis.
Large diameter metal-on-metal (MOM) bearings are becoming increasingly popular for young, active patients. Clearance is a particularly important consideration for designing MOM implants, considering historical experience of equatorial contact and high frictional torque. Lubrication theory predicts increasing the clearance will result in diminished lubrication, resulting in increased friction and wear. Clinical cases of transient squeaking in patients with resurfacing bearings have been noted in recent years, with some reporting an incidence of up to 10% between 6 months and 2 years post-implantation. This study aimed to investigate the impact of increasing clearance on the lubrication, friction and squeaking of a large diameter metal-on-metal resurfacing bearing through frictional studies.
Clinical-grade MOM implants of 55mm diameter and 100μm diametric clearance, and custom-made, 55mm bearings with diametric clearances of approximately 50μm and 200μm (DePuy International Ltd) were tested in a friction simulator. Components were inverted with a flexion-extension of ±25o applied to the head and lubricated with 25% and 100% newborn bovine serum. A peak load of 2kN, with swing-phase loads of 25N, 100N and 300N were applied.
Sound data was recorded during each friction test using a MP3 recorder and pre-amplifier. A microphone was set up at a distance of 50mm from the implant, and data recorded over a minimum of 10 seconds where sound was generated. Sound data was assessed through narrow band analysis on Frequency Master software (Cirrus Research, UK).
Lubrication was assessed by directly measuring the separation between the head and cup during the test cycle by ultrasonic methods (Tribosonics, UK). An ultrasound sensor was bonded to the back of the cup and reflection measurements were taken during the friction tests with a sampling rate of 100Hz. Using equations which related reflection coefficient to lubricant properties and thickness, values for the film thickness were calculated.
The surface replacement with the largest clearance yielded the highest friction factor for each test condition. The difference between the large clearance bearing and the smaller clearance samples was statistically significant in 25% bovine serum, the more clinically relevant lubricant (ANOVA, p< 0.05). The 50μm clearance group yielded similar results to the 100μm clearance bearing, although a slight increase in friction was observed.
Squeaking occurred during every test in the large clearance group. There was a reduced incidence of squeaking in the smaller clearances, with the lowest incidence observed in the 100μm clearance group.
The smallest separation of the head and cup was observed within the large clearance bearings. The best lubrication condition measured ultrasonically was observed within the 100μm clearance bearing. There appeared to be good correlation between friction, lubrication and the incidence of squeaking. This study suggests a large diametric clearance results in reduced lubrication, increased friction and an increased incidence of squeaking. However, there is a minimum diametric clearance that can be tolerated, as clearance must accommodate the manufacturing tolerance.
The term ‘posterior condylar offset’ (PCO) is defined as the distance from a line projected along the posterior cortex of the femur to the maximum convexity of the posterior condyles. Its magnitude has been found to correlate with final flexion following PCL-retaining TKA, if reduced by more than 3mm post-operatively. (
Tibial slope is the angle between a line drawn parallel to the articular surface and a line drawn perpendicular to the long axis of the tibia on a lateral radiograph. Increasing the tibial slope in PCL-retaining TKA has been shown to improve maximal flexion of an average 1.7 degrees flexion for every extra degree on the tibial slope. (
The mean pre-operative PCO was 25.9 mm (21 – 35), whilst the mean post-operative PCO was 26.9 mm (21 – 34). The difference in preoperative and postoperative PCO ranged from −6 mm to + 5 mm (average, +1mm).
Three patients 4% had more than 3mm reduction in their PCO following TKA (range −4mm to −6mm). 16% had their post-operative PCO increased by more than 3mm (range 4mm – 5mm). The remaining 80% had their PCO restored to within 3mm either way.
The mean post operative tibial slope was 6.6° with a range of 5–9°, 38% measuring 6°, 21% at 7°, 17% at 8°and 5° and the remaining 7% at 9°.
Of the three patients whose PCO was reduced by more than 3mm, one had the same flexion 1 year postoperatively, one had an increase of 14 degrees, and unfortunately the third died before their 1 year review.
Using regression analysis, the strongest predictor of one-year flexion for this study group was the preoperative flexion value. The change in PCO and angle of the tibial slope had no significant influence on one-year flexion.
Ceramic on metal bearings for hip replacement have shown reduced friction, wear, and metal ion levels in comparison to metal on metal bearings. Lower wear has been attributed to a reduction in corrosive wear, smoother surfaces and improved lubrication and differential hardness and reduction in adhesive wear. The aim of this study was to further assess the performance of novel differential hardness COM THRs in two different bearing configurations. The effect of bearing configuration was examined by comparing COM (ceramic head on metal liner) with metal-on-ceramic (metal head on ceramic liner) (MOC) bearings in micro-separation hip simulator testing.
Components used were zirconia-platelet toughened alumina (Biolox Delta) heads and high carbon (0.2wt%) CoCrMo alloy cups, tested in COM and MOC configurations, (, (DePuy International Ltd, UK). Micro-separation hip simulator testing was conducted for 2 million cycles (Mc) using a Prosim hip simulator (SimSol, UK), which applied a twin peak loading cycle and walking motions with the prosthesis positioned in the anatomical position. The lubricant (25% calf serum) was changed approximately every 0.33Mc and wear was measured gravimetrically. A negative force was applied to the head during the swing phase, to produce a joint laxity and head – rim contact, the head relocated in the stance phase.
The total overall mean wear rate for the MOC bearings (0.71±0.30mm3/Mc) was significantly higher than the wear rate for the COM bearings (0.09±0.025mm3/ Mc). The contact of the head against the rim of the cup at heel strike caused deep stripe wear on the metallic heads of the MOC bearings. Stripes of metallic transfer were visible on all the ceramic heads (COM bearings). The COM bearings had much lower wear rates than the MOC bearings under harsh micro-separation conditions. This suggests that the head in a differential hardness bearing should be the harder material. The COM concept also provides increased design flexibility; thin metal shells can be used with larger ceramic heads. Additionally the design protects against ceramic liner chipping. COM bearings are currently undergoing clinical trials.
Outcome assessment revealed significant improvement in SF36 even after removal of stabilising system while no worsening of ODI or VAS in comparison with preoperative status.
The implications of this are that vaccination using this peptide might be expected to protect patients about to undergo elective arthroplasty from infection with S aureus whatever its antibiotic susceptibility, so offering a realistic solution to the problem of increasing resistance.
Thrombin related peptide (TP 508) is a 23 amino-acid synthetic peptide that mimics a portion of the receptor-binding domain of the human thrombin molecule.
Thrombin triggers both proteolytic activated receptors and non proteolytic activated receptors to bring about a mixture of responses ranging from tissue breakdown and clot formation, to new vessel formation and tissue repair. TP 508 stimulates only the non proteolytic activated receptors, and this initiates repair and angiogenesis but not clot formation or tissue breakdown Previous studies have shown that TP508 can stimulate repair in the dermal and musculoskeletal tissues by promoting angiogenesis and enhancing the proliferation and migration of cells.
High energy fractures are associated with a delay in healing. We hypothesized that high energy fracture healing would be improved with the use of TP508, and that the dose and site of application would have importance.
24 animals were sacrificed on day 21 and the remaining 56 mice on day 35. Of the 35 day old animals 8 in each group had both femora harvested and the biomechanical properties were tested using the 3-point bending technique. Specimens from the 21 day old animals and remaining 35 day old animals were used for histological analysis.
All 80 animals had digital radiographs taken each week. Using image analysis software five pixel density graphs were generated across each fracture gap. A validated semi quantitative analysis was used to score each graph and the total accumulated for each radiograph. The width of the fracture calus was measured and expressed as a ratio of the femur diameter.
Radiographic analysis showed greater healing of fracture and callus formation in Group I compared to Groups II, III, and IV, at both three and five weeks post-fracture (P< 0.05).
Histological analysis showed an increase in bone formation in group I compared to the other groups.
Osteoarthritis (OA) is characterised by progressive erosion of articular cartilage, which, once started, cannot be halted. The breakdown of cartilage is mediated by proteases, including MMP-3 and -13. These may initially be derived from the synovium but are also produced by OA chondrocytes, particularly in later stages of the disease. In normal articular chondrocytes, the proteases are not expressed and it has previously been shown that this is due, in part, to silencing by epigenetic mechanisms, in particular DNA methylation at so-called CpG sites (Arthritis & Rheumatism 52:3110–24). In OA, chondrocytes increasingly produce the enzymes and stably transmit the abnormal gene expression to daughter cells. This aberrant expression has been shown to be associated with an epigenetic “un-silencing” via demethylation of specific CpG sites within the promoter regions. Why and how this demethylation takes place is not known.
The pro-inflammatory cytokine IL-1beta is of potential importance in OA, where temporary synovitis could provide the cytokine. Moreover, it is well established that IL-1beta upregulates MMPs in chondrocyte monolayer cultures. We investigated whether the IL-1 mediated induction of MMPs was associated with DNA demethylation. Control chondrocytes were isolated from non-OA articular cartilage, obtained with ethical permission from patients with a femoral neck fracture, and expanded in monolayer culture. The cells from each patient were divided into pre-culture control, no-treatment control culture and IL-1 treated culture. When confluent, simultaneous RNA and DNA extraction was carried out. mRNA expression was analysed by RT-PCR and the methylation status of specific CpG sites within the promoters of MMP-3, -13, and IL-1â was determined in the same samples, using methylation-sensitive restriction enzymes and PCR. The pre-culture controls expressed type II collagen and low levels of MMP-3, but not MMP-13 nor IL-1beta. All IL-1 treated samples expressed high levels of MMP-3, -13, and, surprisingly, IL-1beta itself. As predicted, the large increases in MMP-3 and IL-1beta were associated with some loss of methylation at specific CpG sites in the promoter of these mediators with the strongest correlation between IL-1beta expression and promoter demethylation. IL-1beta thus induced its own expression, which was associated with loss of DNA methylation at one specific CpG site in the IL-1 promoter. If these in vitro results have relevance for the in vivo situation, then these findings suggest the following mechanisms for OA progression: An initial inflammatory episode in the synovium could induce IL-1beta in surface chondrocytes. Since this induction is associated with loss of DNA methylation, IL-1beta is now part of the expression repertoire of these chondrocytes and this abnormal expression is stably transmitted to daughter cells. IL-1 then could diffuse deeper into the cartilage to induce its own expression in adjacent chondrocytes, thus providing a continuous supply of IL-1beta even after synovial inflammation had abated. This may explain the unremitting progression of OA.
To analyse the intra-operative variation in mechanical axes of the lower limb at various stages during navigated total knee replacement. A prospective study was performed to analyse the intra-operative variation in the mechanical axes of the lower limb during navigated total knee replacement. All consecutive patients who underwent navigated total knee replacement were included and patients with inadequate data were excluded from the study. The intra-operative initial, trial and the final mechanical hip-knee-ankle axes were recorded from the navigation system. The differences between these axes were calculated and analysed. There were forty patients, of which 24 were females and 16 males with the age ranging from 37–89 (average 68.4) years. The right knee was replaced in 27 and the left knee in 13 patients. The average initial mechanical axes alignment was 0.03° valgus (3° varus to 3° valgus), trial alignment 0.64° varus (3° varus to 1.5° valgus) and final alignment 0.25° varus (4° varus to 4° valgus). Average deviation from initial to trial axes was 0.97°, trial to final axes was 0.74° and initial to final axes was 1.08°. The cor-relation co-efficient between the initial and the trial axes was 0.25, trial and final axes was 0.43 & initial and final axes was 0.09.
This study highlights a significant variation in mechanical axes between the different stages of navigated total knee replacement. The potential sources of intra-operative errors causing these changes could be soft tissue imbalance, variations in implant placement and possible tracker micro motion. Execution of bony cuts in near normal neutral alignment does not guarantee achievement of near normal final alignment. We advocate surgeons to be vigilant to avoid potential malalignment during navigated total knee replacement.
Unlike metal-on-Polyethylene, metal-on-metal (MoM) implants seem to affect the adaptive immune response as evident from the associated perivascular infiltrate containing lymphocytes and plasma cells. This is more pronounced in implant failure secondary to aseptic loosening, and may represent the failure mode. A reduction in CD8+ T lymphocyte counts has also been described with Hip Resurfacing. MoM articulations produce a much smaller order of size of wear particles (nanoparticles) than metal-on- Polyethylene, which may be responsible for the observed adaptive immune system effects. We therefore analyzed the effects of CoCr nanoparticles (CoCrNP) on Dendritic Cells, T cells & B cells.
We produced CoCrNP using repetitive short spark discharges between electrodes of prosthetic CoCr alloy. Electron micrography and Brunauer-Emmet-Teller method both confirmed nanoparticle size. The following experiments were then undertaken.
Dendritic Cells were cultured from mouse bone marrow and incubated with CoCrNP of varying concentrations for 24hrs, or lipopolysaccharide as a positive control. Activation status was then characterized by CD40 expression on fluorescence activated cell sorting (FACS) analysis. T Cell Viability; Cells from mouse lymph nodes were incubated with CoCrNP in varying concentrations. At 48hrs, Propidium Iodide (PI) was added and proportion of CD4+ lymphocytes that were PI+ve determined by FACS analysis. T Cell proliferation; Cells from mouse lymph nodes were cultured in medium without phenol red and incubated with μCD3 (anti CD3), μCD3 + CoCrNP, μCD3 + μCD28 or μCD3 + μCD28 + CoCrNP. At 48hrs, Almar Blue was added &
difference in light absorbance at 570nm &
600nm was then used to determine T cell proliferation at 72hrs. Cells from lymph nodes of an MD4 (Hen Egg Lysozyme (HEL) specific B cell receptor transgenic) mouse were incubated with CoCrNP, HEL (positive control) or CoCrNP + HEL. B cell activation at 48hrs was characterised by CD40 and CD86 expression on FACS analysis.
We found CoCrNP did not significantly increase CD40 expression on DCs, neither did it alter CD40 or CD86 expression on B cells. Using a sublethal concentration of CoCrNP as determined from the viability tests, CoCrNP inhibited CD3 & CD3/CD28 dependent T-cell proliferation. This would indicate CoCrNP reduces T cell proliferation and/or survival, which may explain the observed reduction in CD8+ count with hip resurfacing. Understanding the development of the Peri-vascular infiltrate associated with MoM implants will however, probably require more complex (most likely in vivo) models.
Autologous platelet rich plasma (PRP) has an established history of clinical use in dental and orthopaedic procedures. However, there is little scientific data demonstrating a mode of action and conflicting clinical data to support its use. The aim of this study was to determine the cellular and metabolic pathways by which PRP modulates the osteogenic response. PRP is a concentrate of platelets in a small volume of plasma derived from whole blood. Platelets contain pre-packaged growth factors in & #61537;-granules that are released during clotting at the trauma site and are an essential requirement for the hard (bone) and soft tissue healing process.
S& N’s Caption ™ device, a standalone disposable device that prepares autologous PRP in 15minutes, was used to prepare human PRP. We determined a platelet concentration factor of 3.4& #61617;1.2 fold and significant increases in the concentration of platelet derived growth factor–AB (PDGF-AB), transforming growth factor-& #61538; (TGF-& #61538;) and vascular endothelial growth factor (VEGF). A 5.9 fold increase in VEGF, 4 fold increase in TGF-& #61538; and 1.5 fold increase in PDGF-AB indicate that PRP has the potential to enhance bone repair as each of these growth factors individually and synergistically affect multiple cell responses essential for tissue repair.
An in vitro study was then undertaken to investigate the effect of human PRP compared to human serum on the proliferation and differentiation of human primary osteoblasts (hOBs) and human mesenchymal stem cells (hMSCs). A significant proliferative effect of PRP compared to serum was observed in both cell types. In hMSCs, PRP treatment significantly increased proliferation after 24 hours as determined by Pico green analysis. However, in osteoblasts a proliferative effect of PRP over and above that of serum was not observed until 72 hours. These data indicate that PRP may have specific differing stimulatory effects on each cell type. Quantitative RT-PCR analysis also determined that PRP significantly increased the expression of BMP 2 over and above that of serum in human osteoblasts at both 6 and 12 hour time points. Furthermore, in hMSCs, PRP increased both BMP-2 and alkaline phosphatase gene expression at early time points suggesting the commitment of these cells to the osteoblastic lineage. This hypothesis was consistent with alkaline phosphatase protein expression which was significantly increased at 72hrs in hMSCs and was further confirmed by increased alizarin red staining, indicative of calcium deposition, in long term cultures of hMCSs treated with PRP.
In summary, these data demonstrate that PRP initiates proliferation in hMSCs and osteoblasts, enhances BMP-2 mRNA expression and induces osteoblast differentiation and maturation in human MSC cultures. Together these data demonstrate a positive effect of PRP on osteogenesis and highlight the potential for Caption™ derived PRP to enhance bone repair.
This presentation introduces a new tool to be used in the cementing of acetabular components in total hip arthroplasty, the ‘Rim Cutter’. The Rim Cutter is designed to cut a ledge in the rim of the acetabulum into which a flanged cup can be cemented. The flange is trimmed such that it fits precisely into the ledge cut in the acetabulum. We present the in vitro pilot study of the effect of using this tool on the intra-acetabular cement mantle pressure during cup insertion and also the effect on the depth of cement penetration as the cup is inserted. A significant improvement in both cement pressure and cement penetration over conventional flanged and unflanged cups is noted. Improved cement penetration around the rim of the acetabulum in THR has implications for reducing the rate of aseptic loosening. The pilot study also suggests other beneficial features of using the rim cutter such as improved cup centralisation, control of orientation and the prevention of the cup ‘bottoming out’. Further in vivo studies are required to better assess its efficacy.
Clinical reports of surgical intervention options, such as spacers or hemi-arthroplasties, particularly for treatment of young arthritic patients, have been poor [
Experiments were conducted in an anatomic pendulum friction simulator (SimSol, UK) using the medial femoral condyle of a bovine knee joint articulating against two conforming stainless steel (316L) tibial plates (R=50mm and 100mm). A simplified physiologic knee loading profile was applied represent both low loading and much higher physiological loading conditions, with peak load between 259N – 1.5kN). Tests were conducted in 25% bovine serum and run for 3600 and 300 cycles under the low and high loading conditions respectively. The motion was cycled at 1Hz with amplitude between −10°–13.1°. Cartilage wear was assessed qualitatively from surface roughness measurements using a surface profile using a surface profilometer (Taylor Hobson, UK). The friction and wear of cartilage articulating against the conforming tibial plates were compared to a positive control flat tibial plate model [
The aim of this study was to test the hypothesis that SiCaP bone graft results in superior osseoinduction compared to stoichiometric HA and osseoinduction enhancement using high microporosity materials.
Following euthanasia at 12 weeks histomorphometry was carried out to calculate Percentage of bone, soft tissue and implant area and Percentage of the amount of bone in contact with the calcium phosphate surface (% Bone attachment). Further evaluation of Calcium, Phosphate and Silicon levels within the implants and surrounding bone was carried out by Scanning Electron Microscopy (SEM) and EDAX.
The dynamic association between the immune system and the skeletal system has recently been appreciated. It has been suggested that cells involved in the inflammatory cascade might modulate the bone fracture repair process. Interestingly a number of studies have demonstrated that ability of the T lymphocyte to affect bone remodelling and health profoundly. For example the presence of T lymphocytes has been shown to increase bone resorption during experimental induced arthritis. We wanted to investigate the role of specific T lymphocytes in fracture repair and required an in vivo model to deplete CD4 and CD8 T lymphocytes selectively.
Osteoarthrosis (OA) is often considered to be due to “wear and tear”, aggravated by obesity. However, if developmental dysplasia of the hip (DDH) is treated incorrectly, osteoarthrosis can also occur at a very young age. We obtained cartilage from the femoral head a 23 year-old female after arthroplasty for DDH; from a 14 year-old male, resected for paralytic dislocation, and from OA and control patients. This provided a unique opportunity to compare the cellular and epigenetic features of OA in older patients with those in a young control as well as a DDH patient. We have recently defined the cellular and epigenetic features of idiopathic OA, in particular the association between induction of proteases and loss of DNA methylation in the respective promoter regions (
The cartilage of the 14-year old showed high cellularity and absence of immunostaining for all proteases investigated. Apart from the higher cellularity, this was similar to the ‘control’ cartilage obtained from patients with a fracture of the femoral neck. We had previously shown that, as OA progresses, more chondrocytes become immunopositive for the degradative enzymes and these cells divide so that in the typical clones of OA all cells synthesize the proteases. The cartilage from the 23-year old DDH patient showed extensive loss of proteoglycans from the superficial zone and fibrous repair tissue covered some areas. Nearly all chondrocytes produced the proteases and clones had formed, as in idiopathic OA. Since these sample were from the base of the femoral neck, where in idiopathic OA good cartilage often remains even in severe OA, the disease process must have reached an early end-stage in this young patient. The findings indicate that severe OA, as defined by the presence of clones that produce degradative enzymes, can develop very quickly. Interestingly, the expression and synthesis of degradative enzymes by OA chondrocytes was the same in juvenile and old-age OA. and their abnormal expression was associated with “unsilencing” via DNA demethylation in both juvenile and old-age OA. The results thus suggest that age per se is not a major determinant of OA progression.
to develop an experimental model which would simulate the clinical revision hip scenario and determine the effects of alendronate coating on porous tantalum on gap filling and bone ingrowth in the experimental model.
Septic Arthrits & osteomylelitis has traditionally been managed by intravenous antibiotics for 4 to 6 weeks. This requires a prolonged in patient stay, inconvenience to parents, morbidity and unnecessary cost. A number of authors have suggested that shortened course of intravenous antibiotics 7–10 days are effective.
In 2001 we started to prospectively evaluate a shortened 3 day of intravenous antibiotic regime. We prospectively treated 36 cases of acute osteomyelitis and 30 cases of acute septic arthritis in children. These were confirmed by positive blood culture, positive aspirate culture, raised WCC in joint aspirate for septic arthritis or positive bone scan/culture for osteomyelitis. These patients were treated with a shortened course (3 days) of intravenous antibiotics following surgical drainage when required. Serial measurements of inflammatory markers and clinical status were recorded. On Day 4 of admission if clinical and biochemical parameters improved patients commenced high dose oral antibiotics. If no improvement they continued IV abx and consideration for repeat washout given. Patients discharged with three week course of antibiotics. Endpoint analysis of duration of IV administration, inpatient stay, readmission/ reoccurrence was undertaken.
The addition of second strand resulted in a marked improvement in displacement with Fibre wire and variations between different samples were smaller than in any other group tested (SD 0.6mm)
Fibre wire has similar strength to failure when compared the commonly used thickness of stainless steel wire for fixation of patella. Use of tensioning device produces interfragmentary compression in a reliable and reproducible manner. The addition of second loop of fibre wire, separately tensioned results in significant improvements in interfragmentary compression and resistance against displacement.
Septic arthritis of the hip is the commonest joint infection and unfortunately the most devasting location. The most serious complication of the pyogenic arthritis of the hip in children and especially in newborns and infants is avascular necrosis of the femoral head which can lead to partial or complete destruction of the capital femoral epiphysis, the growth plate or both.
The aim of the study was to evaluate the residual deformity after late treatment of septic arthritis of the hip in infancy.
The present study included the review of 112 children under the age of 15 with bacteriologically proven septic arthritis of the hip in Prishtina University Hospital-Paediatric Orthopaedic Unit between September 1985 and January 2002. Their ages ranged from 7 days to 14 years, 72 boys and 40 girls with 112 involved hips. All underwent joint aspiration monitoring by real-time ultrasonography and fluid analysis including culture. On the anterior image the distance between the anterior outline of the femoral neck and the anterior joint capsule was measured in millimeters. The length of the follow-up was 3–20 years.
Delay in Hospital admission was observed in 30 (27%) of patients. Eighty-two (73%) were admitted during the first week after onset of complaints. ESR was elevated initially in 87.5% of the cases. The mean ACD in hips with septic arthritis was 13.5mm (ST=0.75mm) and 3.9mm (ST=0.45 mm) in the asymptomatic hips. There was a significant difference in mean ACD for affected and unaffected sides. Complications were: one patient died from sepsis complications. In 14 patients (12.5%) there was destruction of the joint cartilage; pathological dislocation of the hip in 12 cases, 10 of whom were under the age of 6 years; also there were growth changes because of physeal arrest in 6 cases.
Delay in diagnosis and failure to begin treatment promptly are the most common reason for late complication of infection. Poor prognostic factor was also the patient age if it was less than 1 year.
Maggot therapy as an ancient method is succesfully used for treatment of acute and chronic wound infections in traumatology and orthopaedics. In this study, for the first time, the influence of sterile maggot excretions of Lucilia sericata on Pseudomonas aeruginosa (PAO1) biofilm formation on three common used orthopaedic materials was investigated.
Sterile maggot excretions were collected according to a standardized method and the protein concentration was measured. The influence of the excretions on PAO1-biofilm formation was tested on comb-like devices, especially designed for these experiments, made from polyethylene, titanium and stainless steel. These combs were made to fit into a flat-bottom 96-wells microtiter plate. In the wells a suspension of PAO1-bacteria, nutrient medium and maggot excretions were pipetted. In the control wells, no excretions were added. Combs were placed in the wells and incubated for 24 hours at 37°C. The formed biofilms were stained in crystal violet and eluted with ethanol. The Optical Density (OD 595 nm) was read to quantify biofilm formation. The experiments were conducted with excretions from young maggots (Instar-1 maggots) and full grown maggots (Instar-3 maggots). All experiments were done in quadruplicate.
The following can be concluded: PAO1-biofilm formation is the strongest on polyethylene and the weakest on stainless steel. Sterile maggot excretions are effective at preventing initial biofilm formation (p≤0.013) as well as preventing additional accumulation after its initiation (p≤0.038). The excretions even cause a significant breakdown of an existing biofilm (p≤0.028). Excretions from full grown maggots are more effective than those from young maggots.
This study shows for the first time that sterile maggot excretions of Lucilia sericata inhibit biofilm formation, prevent its further grow and break down existing biofilms. While biofilm formation on orthopaedic materials is a severe complication, this experimental study could indicate a new treatment for biofilm formation on infected biomaterials.
Persistent wound drainage after total joint arthroplasty (TJA) has been associated with a higher incidence of superficial and deep periprosthetic infection but the predictors for prolonged drainage and its outcome have not been thoroughly studied.
A consecutive series of 7,153 TJA cases performed between 2000 and 2006 at our institute, were recruited into this study. There were 301 cases (4.2%) of persistent wound drainage, defined as discharge from the wound for > 48 hours. The cases were matched in a 2:1 ratio for type of surgery, joint replaced, and date of surgery.
This study identified higher BMI (p< 0.005), malnutrition as defined by serum albumin< 3.4g/dl (p< 0.04), longer operative time (p< 0.01), and higher medical comorbidities, in particular diabetes (p< 0.001) as important risk factors for persistent wound drainage. In addition, patients in the drainage group were more likely to have a peak INR of > 1.5 (p< 0.001) during their hospital stay. Patients with wound drainage had a significantly lower hemoglobin postoperatively (p< 0.01) that necessitated greater number of postoperative allogenic transfusions (p=0.004). The hospital length of stay for the drainage group was also significantly higher (p< 0.005). One of the major risk factors for development of deep infection was prolonged drainage (> 7 days). In the deep hematoma and periprosthetic subgroups, the mean of delay in treatment was 6 days in those with retention of the prosthesis and successful outcome, and 9.5 days for those with failure of incision and drainage leading to resection arthroplasty (p= 0.03).
72% of the patient were successfully treated by oral or intravenous antibiotics. 27% required at least one re-operation for deep hematoma and 13% developed deep periprosthetic infection, resulting in 6% rate of resection arthroplasty. 1.5% of those with drainage remained in girdlestone status.
This study suggests early surgery for persistent drainage and avoidance of aggressive anticoagulation.
Several methods of surgical treatment for pyogenic spondylitis have been reported including anterior approach, staged and simultaneous anterior decompression and posterior stabilisation. The use of anterior implants in the presence of infection presents still a challenge for spine surgeons.
Retrospective analysis of the clinical and radiological outcome of patients suffering from pyogenic spondylitis of the cervical and lumbar spine necessitating surgical treatment for intractable pain, instability and neurologic impairment.
Seventeen patients with spondylitis associated or not with paravertebral abscess were treated by one stage surgery (first: anterior decompression and placement of titanium mesh cage, filled with autologous iliac bone graft; second: posterior transpedicular instrumentation and fusion). The age of the patients was 54 ±15 years. Most of the patients had systematic problems such as lung tuberculosis, hepatic cirrhosis, diabetes mellitus or chronic renal failure. Patients were evaluated before and after surgery in terms of pain and neurological level, sagittal spinal balance and radiological fusion. All 17 patients were followed for 45 months.
Average duration of both surgeries was 4.5 hours. The VAS score improved from 7 (preoperatively) to 2 (postoperatively). The correction of the segmental kyphotic deformity was 6o, without loss of correction or cage migration or instrumentation failure. All patients with incomplete neurologic impairment improved postoperatively. There was neither migration of mesh cage nor posterior instrumentation failure at the follow up observation. There was an approach-related abdominal hernia.
This clinical study showed that patients with cervical and thoracolumbar osteomyelitis necessitating surgery for certain indications can successfully undergo instrumented combined, one-stage, same-day surgery. The presence of the mesh cage anteriorly at the site of infection had not negative but beneficial influence on the course of infection healing, and it additionally stabilised the affected segment, maintaining sufficient sagittal profile.
Brucellosis is a well known zoonosis transmitted to humans through consumption of raw milk ors in related products. Interhuman transmission is rare. Osteoarticular involvement of brucellosis is not uncommon. The mean averages are around 10% in the Brucella mellitensis and Brucella abortus, so the more severe complications are due to B. mellitensis. Actual prevalence in West European counties is rather scarce but it has not always been as such.
We presented 6 cases of bone affection (all of this focused on the lumbar zone) due to brucellosis recovered from the different burial and different times that was studied morphologically and then verified with molecular analysis. The most ancient case is a vertebral spondylitis from the Calcholitic of Alava (Basque County), the second belongs to a vertebral involvement from the Late-Roman period of the Alicante (5th to 7th century), three other cases were found in different burials (Alava and Sevilla) dated from the High Medieval epoch and the Islamic Medieval period (in the case of Sevilla), the last one is the most bizarre as it is a carpal fusion and vertebral spondylitis from the Medieval cemetery of Monte d’Argento (Fondi, Rome) dated in the 12th century. The actual rates of wrist affection by Brucellosis are over 3.5%. On all the pieces accurate analyses of ancient DNA of Brucella mellitensis were performed.
Athletes are prone to iterated traumatic straining of sacroiliac joints and insertion of muscles in pelvic bones.
The aim of our study was to show the connection between iterated trauma and staphylococcal infection in athletes.
A compilation of data concerning 22 patients, all high-ranking athletes in Sweden, with pelvic skeletal infection (symphysitis, sacroiliitis and acetabular necrosis) is presented. Most of them were ball-players, 2 females and 20 males with an average age of 21 years. The onset was acute or subacute and the disease was commonly misinterpreted, mainly as an acute abdominal disease. Four patients erroneously underwent laparotomy for suspected appendicitis. Eight patients had skin lesions (5 purulent and 3 uninfected) at the onset and thus had a portal for possible entry for a bacterial impact in the pelvic skeleton.
The only verified bacterial aetiology was Staphylococcus aureus in 19 cases (culture of blood and/or aspirated samples in 18 and serology only in 1). An early scintigraphy was of greater value than X-ray for diagnosis and was positive in 8/10 evaluable cases. In all, 12/18 had early positive plain radiological findings. Another patient (#22) had, except skeletal infection, a psoas abscess, diagnosed by Magnetic Resonance Imaging (MRI).
Antistaphylococcal drugs administered parenterally for 1–2 weeks followed by oral drugs for a few months comprised a successful treatment and no patient had serious sequelae or relapse.
The occurrence of abdominal and/or lower back pains concomitant to fever in young persons engaged in elite team sports should lead to a suspicion of pelvic pyogenic infection. Early scintigraphy and cultures of blood and aspirated material from the infection site was essential for the diagnosis. MRI has also been shown to be valuable.
The use of platelet-leukocyte gel (PLG), made from platelet rich plasma, to stimulate bone formation and wound healing has been investigated extensively. As leukocytes play an important role in the innate host-defence, we hypothesised that PLG might also have antimicrobial properties.
The purpose of this study was to investigate the antimicrobial activity of PLG against Staphylococcus aureus in an in vitro experiment. To determine the contribution of myeloperoxidase (MPO), present in leukocytes, in this process, MPO release was measured.
Platelet rich plasma (PRP) was prepared from whole blood of 6 donors. In this process platelet poor plasma (PPP) was obtained as well. PLG was prepared by mixing PRP with either autologous (PLG-AT) or bovine thrombin (PLG-BT). The antimicrobial activity of PLG-AT, PLG-BT, PRP and PPP was determined in a bacterial kill assay, containing 1x106 CFU/ml of Staphylococcus aureus, during a 24-hour period. MPO release was measured by ELISA.
Cultures showed a rapid decrease in the number of bacteria in the presence of both PLG-AT and PLG-BT, which was maximal between 4 and 8 hours, to approximately 1% of the bacteria in controls. Also PRP and PPP induced a statistically significant bacterial kill, but the effect of PLG-AT was the largest (p=0.093 vs. PLG-BT; p=0.004 vs. PRP and p< 0.001 vs. PPP). PLG-AT, PLG-BT and PRP showed a comparable, gradually increasing MPO release for 8 to 12 hours. Some MPO was also measured in the PPP samples. No correlation between MPO release and bacterial kill could be found.
PLG appears to have potent antimicrobial capacity, but the role of MPO in this activity is questionable. PLG might represent a useful strategy against postoperative infections. Further research should investigate its antimicrobial capacity in the in vivo situation.
A new type of metallic silver bone cement was previously shown to be effective against both antibiotic sensitive and resistant bacteria.
In this study the efficacy of silver bone cement in preventing methicillin- sensitive Staphylococcal infections was compared with plain and tobramycin-containing bone cement, in a rabbit contaminated implant bed model.
In 48 rabbits 0.6%-silver, 1%-silver, plain or tobramycin-loaded (tobra) PMMA bone cement (Simplex®P; Howmedica, Ireland) was injected into the medullary canal of the right femur after contamination of the implant bed with 105, 106 or 107 colony forming units (CFU) of Staphylococcus aureus. After 14 days bone was collected, homogenised and plated on blood agar plates. After an overnight incubation the number of CFU’s was counted. Bone was also collected for pathological analysis.
The plain and silver cement rabbits were all infected, whereas with tobra cement only 2 rabbits (17%) were infected (p< 0.001). The number of bacteria cultured from bone adjacent to the cement, was 6.4±0.3 and 6.1±0.3 for the 0.6% and 1%-silver rabbits. For the rabbits with plain and tobra cement this was 6.2±0.2 (p> 0.95) and 0.0±0.0 (p< 0.001). Two tobra rabbits had a positive culture of a distal bone sample. Histological sections of plain, 0.6% and 1%-silver cement rabbits all showed signs of infection; these signs were absent in the tobra rabbits.
Silver cement was not effective in preventing infection. However, in the current model bacteria are present directly at and distant from the implant surface, whereas silver cement predominantly exhibits an antimicrobial effect at the direct cement surface. The non-eluting silver cement seems less useful in situations where there are also bacteria present in surrounding tissues, like revision surgery. Whether silver cement has relevance in preventing bacterial colonization of cement, for instance in late haematogenous infections, or not remains to be seen.
The aims of the study presented here were to compare the frequency of surgical glove perforation among major and minor orthopaedic surgical procedures and to determine the efficacy of use of double glove in these procedures.
A prospective study was performed to assess the perforation rate of surgical gloves in 100 major (total hip and knee arthroplasty) and 100 minor (arthroscopy) orthopaedic procedures. Glove perforation rate, location of perforation, and time of operation were analysed. In 200 procedures, 1528 gloves were inspected; 622 inner gloves, 906 outer gloves were examined. All members of the surgical team wore double gloves in major and minor surgical procedures.
The overall perforation rate was 242 out of 1528 gloves (15.8%), and 70 out of 200 operations (35%) (major versus minor surgical procedures, 21.6% versus 5.6%, p< 0.05, and 63% versus 11%, p< 0.001, respectively). For major procedures, 224 glove perforations were determined, of which 23 were in the inner glove and 201 in the outer glove. For minor procedures, 13 glove perforations were observed, and no perforation were found in the inner gloves used by the surgical team for minor procedures. The right thumbs and left index finger had more punctures than others. The mean operative time for major procedures was 76.5 ± 22.4 (range; 45 to 125) min while that for minor procedures was 29.5 ± 12.6 (range; 17 to 60) min (p< 0.001).
Double gloving has proven to be an effective second barrier. We recommend the routine use of the double gloving method in major and minor orthopaedic procedures, because the double gloving method can significantly reduce the perforation of inner gloves.
Limb salvage through total femur (TOFEM) prosthesis is a rare procedure. The infection rate is high due to the large implant surface, a long OR-time and often severely compromised soft tissues. In case of infection, the one-stage procedure is the way of revision to avoid impairing instability for the patient.
Between 1996 and 2005, 46 one-stage exchanges were performed in 37 patients. Twenty-three patients were available for review in 2006. Thirteen had died, 1 could not be located. The infection-free periods, subjective satisfaction with the procedure and clinical outcome were evaluated. The average follow-up time (FU) was 46 months (8/104). Male/female ratio was 10/27, and the average age 66 years. (30/87). The average number of revisions before the TOFEM was 5 (1/11).
Indication for a TOFEM was fracture in 43%, bone loss in 51% and others in 6%. Infection occurred at primary intervention in 32%, in connection with revisions in 18% or delayed in 49%.
Sixteen patients were cured through a one-step procedure with an average FU time of 46 months. Ten patients underwent further revisions. Two or more exchanges were carried out in 6 cases with success. Patients’ satisfaction rate was 55%. Thirteen were valued unsatisfied. Eight exarticulations became necessary later and 5 patients died in the course of the treatment. Two of those were exarticulated before.
The one-stage exchange is a promising procedure towards avoiding loss of the limb. A high complication rate exists and secondary exarticulation may still become necessary.
Wear debris from metal on metal (M/M) hip resurfacing and metal on polyethylene (M/P) total hip replacements have different biocompatibilities. M/P wear particles have a foreign body effect
M/P wear debris contains nickel and M/M wear debris contains cobalt. Nickel and cobalt are both heavy metals, required as trace elements for some bacteria but potentially toxic to bacteria in high concentrations.
Cobalt kills Helicobacter Pylori at concentrations as low as 30 ppb
The purpose was to investigate the effects of nanoparticulate wear debris and their heavy metal constituents on bacterial growth.
Samples of Coagulase Negative Staphylococci (CNS), Staphylococcus Aureus and MRSA were cultivated to compare their growth in M/M wear debris, M/P wear debris, nickel, cobalt and control culture mediums over 48 hours. Nickel was toxic to CNS (p=0.006) and MRSA (p=0.048). Cobalt also retarded the growth of all three bacteria. M/M wear debris increased the growth of CNS 183 times at 48 hours (p=0.044), Staphylococcus Aureus and MRSA. M/P wear increased the growth of Staphylococcus Aureus 120 times at 48 hours (p=0.021), CNS and MRSA.
M/M and M/P nanoparticulate wear debris accelerate the rate of growth of common organisms that infect prosthetic hip joints, the clinical significance of which is uncertain. In isolation, the heavy metals contained within wear debris retard bacterial growth, particularly nickel.
Nanoparticulate wear debris does not possess the toxic effects of its constituent metals on bacteria. This reinforces the safety of wear debris but also shows the potential for anti-bacterial effects to be harnessed.
Antigranulocyte scintigraphy with the use of monoclonal antibodies or antibody fragments (leukoscan) is a promising diagnostic tool that has been used widely during the recent years for the establishment of prosthesis infection after total hip or knee arthroplasty.
In the present study we report the Ioannina University Hospital experience in the diagnostic efficacy of leukoscan for the diagnosis of prosthesis infection in patients with total hip or knee arthroplasty.
We considered all patients with suspected total hip or knee arthroplasty infection that had undergone a leukoscan examination for the diagnosis of this infection in our department during the year 2004. All patients underwent a 3-phase bone scan and a subsequent leukoscan. For the whole group of patients the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were calculated by comparison of the results of three-phase bone scan or leukoscan with the results obtained from cultures of synovial fluid obtained from articular puncture or cultures of intraoperative sampling from those patients that had undergone a revision surgery.
A total of 19 patients with total joint arthroplasty (12 THA and 7 TKA) and suspected prosthesis infection were included in the study. The mean age of patients was 67 years. Twelve patients had verification of prosthesis infection in cultures. The overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for the three-phase bone scan were 54%, 83%, 88%, 45% and 63% respectively. On the contrary, the overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for leukoscan were 75%, 86%, 90%, 66% and 79%, respectively.
Antigranulocyte scintigraphy with the use of monoclonal antibody fragment sulesomab (leukoscan) had good but not perfect diagnostic performance for the diagnosis of prosthesis infection in patients with total hip or knee arthroplasty.
Tuberculosis continues to increase in England. London accounted for a substantial proportion of cases in 2005 (43%) and had the highest rate of disease. Spinal TB is the most common skeletal manifestation. The diagnostic evaluation of spinal TB is hampered by the difficulty of MRI interpretation and failing to keep a high index of suspicion.
The mode of presentation of spinal tuberclosis, surgical procedures and outcome of patients were highlighted. Various dermographic parameters were evaluated.
A prospective cohort study was conducted. Cross sectional sampling of patients presented with spinal TB between the years of 1999–2006 in two main hospitals covering large population of East London, Royal London Hospital and King George Hospital.
One hundred and twenty three patients (mean age: 34 years) were identified. Asians represent the highest group affected (63%), then appear Afrocarribean (28%). White British represent only 6.5%. Frequency of occurence was as follows: dorsal spine 45%, lumbar spine 33%, multiple regions 11%. Delayed diagnosis was made in 34% of patients, 44% of whom were over 6/12.
Backpain or neckpain was the presenting complaint in all of the patients (100%), whereas neurological signs were found in 37%. Systemic manifestations presented in 38%. Spinal surgical procedures were needed in 44% of cases. Approximately 30% of them had partial recovery and 9% had complete recovery.
The incidence of spinal TB is on the increase. A high index of suspecion is required to avoid delay in the diagnosis. Knowledge of the patients’ background may help making appropriate early referral for MRI.
Infection of a megaprosthesis implanted following tumor resection leads to major morbidity and sometimes amputation. Their treatment is like treatment of infected total knee or hip prosthesis, except there is a dramatically larger dead or infected tissue, and immune deficiency due to oncologic treatments. Two-stage revision of infected megaprosthesis seems to be the safest solution except amputation.
Between 1990–2005, we have implanted 282 megaprosthesis in the upper and lower extremity following tumor resection. Sixteen prostheses became infected after a median of 48 months (2–96) following the index intervention. All of them underwent two-stage revision. The infections were staged after Mc Pherson classification, revealing that 75% of them were ‘stage IIIB’. The first stage included debridement, insertion of culture specific antibiotic-loaded bone cement in the form of beads and/or rods, temporary fixation with a custom made IM nail or self-designed, mobile hinged-joint prosthesis covered with antibiotic- loaded PMMA. The most common grown microorganism was MRSA. Following parenteral antibiotherapy, the second staging was performed after a median of 6 weeks (5–11). The reconstruction stage included reimplantation of a cemented prosthesis in 5 patients, a cemented prosthesis in 6 patients, arthrodesis through segment transfer with an external fixator in 4 patients. Eight patients necessitated a local or a distant flap for soft tissue coverage. A patient with recurrent deep infection was amputated.
Patients were followed up for a median of 86 months (24–146). Infection was controlled in 15 patients, with an overall success rate of 94%. The mean functional outcome for the retained limb using the MSTS score was 70%.
Two-stage revision in infected mega prosthesis yields results close to conventional joint replacements, if general guidelines are followed and good soft tissue coverage is provided.
Posttraumatic infection and osteomyelitis is a difficult to treat complication. Despite surgical interventions, there is great risk for recurrence of the infection and development of an invalidating osteomyelitis. For this reason, a retrospective, case control cohort study on patients with posttraumatic osteomyelitis was performed to evaluate the clinical outcome of a new therapy, i.e. VAC Instillation with Lavasept®, an instillation technique applied after the initial surgical debridement.
In the time period from 2/1999 to 2/2003, thirty three patients with posttraumatic osteomyelitis were included and were treated with the VAC technique and the white polyvinyl alcohol (PVA) foam in combination with lavasept® instillation. The PVA foam was instilled 3 times per day with a disinfectant fluid agent lavasept 0.2 % (polyhexanidum solution). The average time of treatment was 21 days (6–60). The average time that infected wounds became sterile or skin bacteria could be cultured (88.1 %) was 12 days (range 4 – 38; SD 8.9). The follow-up time was up to 72 months. For comparison a historical control group of 94 patients (male 58, mean age 47 (r 9–85) matched for site and severity of osteomyelitis, was identified in hospital records for a period of 20 years (1982–2002). These patients were treated with debridement, lavage and gentamycin beads.
Both groups were statistical comparable to sex, age, comorbidity and site of the osteomyelitis. In the V.A.C.® Instill® group the rate of recurrence of infection was 3/30 (10%), whereas 55/93 (58.5%) of the controls had a recurrence (p< 0.0001). Moreover, in those treated with VAC Instillation, the duration of hospital stay was shorter and the number of admissions and surgical procedures were smaller as compared with the controls (all p< 0.0001).
We conclude that in posttraumatic osteomyelitis VAC Instillation treatment may improve clinical outcome and reduce the need for repeated surgical interventions and hospital admissions in comparison to the present standard approach.
The formation of bacterial biofilms is increasingly recognised as the leading cause of chronic infections. It limits the application of implant materials including catheters, heart valves, or orthopaedic prostheses. It is generally assumed that the infection persists because bacteria organised as biofilms escape the host defence mechanisms. Nevertheless, when studying patients with infected implants, we found a massive infiltration of leukocytes particularly polymorphonuclear neutrophils, PMN, into the site of infection, which led to the question, whether the PMN interact with the bacterial biofilm or not.
The interaction of human PMN with Staphylococcus aureus biofilms was studied in vitro.
S.aureus was cultivated on glass cover slips for various times under conditions allowing formation of biofilms. Adherence of PMN to biofilms and phagocytosis of the bacteria were observed by confocal laser scan microscopy and time lapse video microscopy.
Migration of PMN on and into the biofilm was identified as being phagocytosis, apparent as uptake of bacteria into the cell. Concominantly, in the wake of migrating PMN bacteria depleted zones appeared, which increased in size with time. In addition to phagocytosis, release from PMN of DNA and also of elastase was seen, suggesting the formation of neutrophil extracellular traps (NETs). So far, the signal for DNA release and NET formation has not been identified; of note is, however, that they occurred preferentially on established “old” biofilms and in the absence of the opsonising human serum, while phagocytosis was most efficient with developing “young” biofilms.
Taken together, our data provide evidence that bacteria in biofilms are not entirely protected against host defence but that phagocytosis is still possible, especially when the biofilm is opsonised with human serum. Whether NET formation also contributes to bacteria killing in biofilms cannot be decided as yet but remains an attractive alternative.
Callus distraction over an intramedullary nail is a rarely used technique for the reconstruction of intercalary defects of the femur and tibia after radical debridement of chronic osteomyelitic foci.
The aim of this study was to summarize our experience of distraction osteogenesis with an external fixator combined with an intramedullary nail for the treatment of bone defects and limb shortening produced as a result of radical debridement of chronic osteomyelitis.
Sixteen patients aged 16 to 63 years underwent radical debridement to treat nonunion associated with chronic osteomyelitis of 8 tibias and 8 femurs. The lesions were staged as Cierny and Mader type IVA (10) and IVB (6). The resulting segmental defects and any limb length discrepancy were then reconstructed by distraction osteogenesis over an intramedullary nail. A monolateral frame was used for the femur, and a ring type external fixator for the tibia. Two patients required local gastrocnemius flaps. Free non-vascularised fibula grafts were added to the regenerate for augmentation of a femoral defect at the time of external fixator removal and locking of the nail. At the latest follow-up, functional and radiographic results were evaluated using the Paley’s criteria.
In the femur, the mean defect was 10 centimeters (range 6 to 13 centimeters), while in the tibia it was 8.4 centimeters (range 5 to 11 centimeters). The mean external fixator index was 13.5 days per centimeter, the consolidation index was 36 days per centimeter and the mean time to union at the docking site was 9 (range 5–16) months. The average follow-up was 31.3 months. We obtained 81.25% (13 of 16) excellent results in terms of both bone and functional assessment. There were two recurrences of infection necessitating nail removal. These patients underwent revision with an Ilizarov fixator. Subsequently, infection was controlled and the non-unions healed.
This combined method may prove to be an improvement on the classic techniques for the treatment of long bone nonunions associated with chronic osteomyelitis, in terms of external fixation period and consolidation index. These appears to be no increase in the risk of complications, and the earlier removal of the external fixator is associated with patient comfort, decreases the complication rate and facilitates convenient and quick rehabilitation.
Low virulent chronic prosthetic infection might be indistinguishable to aseptic loosening. Polymerase chain reaction (PCR) has been introduced to improve bacterial detection of implant infection. However, there is great risk of false positive results when using broad range/universal PCR primers. The source of DNA contaminants may be of environmental origin as well as the reagents employed.
To study the presence of bacterial DNA in culture negative biopsy specimens by using defined criteria for PCR positivity.
We included six specimens from each of 21 patients preoperatively considered having aseptic loosening of a hip prosthesis. These 126 specimens were culture negative after seven days of incubation. Prior to incubation, the specimens were divided, and half of each specimen was processed for PCR.
Three sets of primer pairs targeting the 16S rRNA gene were developed.
Nine specimens from culture proven prosthetic infections and nine specimens from primary prosthetic surgery served as positive and negative controls, respectively.
A specimen was considered PCR positive if:
bacterial DNA ≥ 2 times than the reagent control, and a positive PCR signal for ≥ 2 primer pairs.
All the 126 patient specimens were PCR negative and the nine positive controls were positive. One of nine negative specimen controls was PCR positive, DNA sequencing demonstrated a non-pathogen. Five single PCR reactions (1.3 %) were positive.
This study underlines the importance of establishing stringent criteria for interpretation of PCR positivity to apply to clinical specimens. By the criteria used, five single positive PCR reactions were identified as false positives. Positive PCR reactions in all of the specimen positive controls prove the detection ability of the method. One PCR positive result in a specimen negative control demonstrates the contamination risk in collection and handling of biopsies.
In conclusion, by using a semiquantitative PCR and stringent criteria for PCR positivity we were unable to detect any infections missed by culture.
P.aeruginosa causes acute and chronic-destructive infections, particularly wound infections, or device-associated infections by colonising respiratory tubes, catheters, or implants. The pathogenicity of P.aeruginosa is largely attributed to the relative resistance towards host defence. Especially when organised as biofilms, the bacteria evade phagocytosis and killing by polymorphonuclear neutrophils (PMN).
To elucidate the evasion mechanisms, the migration of PMN towards and through P.aeruginosa biofilms was studied. Migration of PMN towards P.aeruginosa biofilms was tested using various in vitro techniques.
We found that PMN migrated towards developing P.aeruginosa biofilms, attracted by the quorum-sensing molecule N-3-oxododecanoyl homoserine lactone (3OC12-HSL). Mature biofilms which no longer produced 3OC12-HSL did not attract PMN. Addition of interleukin 8, a potent chemokine, restored the migratory capacity. Once arrived at the biofilms, PMN readily attached with no important difference between developing and mature biofilms. Migration into and penetration of the films, however, was only seen with developing films. By mass spectroscopy it became obvious that a major difference between developing and mature biofilms was the composition of the extracellular polymer substance, of which alginate is a prominent component. A series of experiments with isolated alginate showed that PMN did not migrate on or into alginate-containing matrices, but remained affixed at the contact site just as they did on mature biofilms. The mechanism of this firm attachment is still under investigation; prominent up-regulation of various adhesion molecules was seen, which could provide possible explanation.
Mature biofilms, most probably due to the composition of the extracellular polymer substance, do not allow the penetration of PMN. Consequently, bacteria embedded in deeper layers of the biofilm are protected against the host response. Due to the restricted movement of PMN, the bactericidal activity of PMN is only efficient against bacteria in the immediate vicinity, explaining the inefficient host defence.
Exchange of infected implant using antibiotic-impregnated cement is the treatment of choice in prosthetic joint infection (PJI). We presented our experience using one or two-stage exchange with uncemented implants.
From January 2000 to June 2006 patients with a PJI that were treated with one or two-stage exchange with uncemented implants, were prospectively followed up. The treatment protocol consisted of radical excision of devitalized tissue and of maintaining a high serum antibiotic concentration during surgery followed by systemic antibiotic administration according to the microbiology results. Only patients with ≥6 months of follow-up were included. Good evolution was considered when symptoms and signs of infection disappeared and the C-Reactive Protein was normal.
Forty-two patients were included in the study, of whom 25 were male. The mean age was 70 years. The most common symptom was pain (100%) and radiological signs of prosthesis loosening were present in 36 cases (85.7%). Histology was positive in 32 patients (76.2%). Coagulase-negative staphylococci was the most common microorganism (23 cases) followed by S. aureus (5 cases). One-stage exchange was performed in 18 patients, and the long stem component was always uncemented. In one case an acute infection after the arthroplasty obligated to perform an open debridément without implant removal. After a mean follow-up of 31 months (range: 6–84) all patients had a good evolution. In 24 cases a 2-stage exchange with a joint spacer with gentamycin (Spacer-G) was performed. In all cases the definitive arthroplasty was performed using an uncemented long stem. Good evolution was documented in all but one case with persistent infection due to S. aureus after a mean follow-up of 19 months (range: 12–48).
Our results suggest that uncemented arthroplasty following a protocol based on radical debridément and systemic antibiotic therapy during and after surgery is a useful approach in PJI.
In primary total knee arthroplasty (TKA) performed under ischemia the antibiotic prophylaxis is administered 15’ before inflating the tourniquet. The infection rate in TKA is higher than in hip arthroplasty. We hypothesise that ischemia could impair the efficacy of the antibiotic. The objective of our study was to compare the effectiveness of two schedules of antibiotic administration.
We conducted a randomised and a double blind study. Patients were assigned to receive placebo 15’ before inflating tourniquet and cefuroxim 1.5 g 10’ before releasing the tourniquet (experimental arm) or cefuroxim 1.5 g 15’ before inflating tourniquet and placebo 15’ before releasing tourniquet (standard arm). In both arms cefuroxime 1.5 g was administered 6 hours after finishing surgery. The variables gathered were: age, sex, indication for TKA, co-morbidity, ASA score, duration of the operation, number of blood transfusions, days of hospitalisation and number of surgical site infections after 3 months of surgery. Categorical variables were compared using the χ2 test or the Fisher exact test and quantitative variables using Student-t test.
Nine hundred and eight patients were randomised and 466 and 442 patients were allocated to experimental and standard arms respectively. Both groups were similar and there were no differences in deep and superficial infection rates, 1.39% and 4.18% for experimental arm and 3.39% and 3.17% for standard arm (p> 0.05). The experimental arm had a lower global and deep infection rate than the standard arm when the length of surgery was lower than the 75th percentile (global: 4.03 vs 7.93%, p=0.04, deep: 1.72% vs 4.44%, p=0.07).
The administration of antibiotic prophylaxis 10’ before releasing the tourniquet decreases the surgical site infection rate when the duration of surgery is lower than the 75th percentile.
Soft tissue biopsies may prove culture negative in biofilm prosthetic infections. Identification of the causative bacteria could be achieved by either scraping of the prosthetic surface or by sonication of the entire implant. These techniques have not been thoroughly studied in experimental models where the biofilm is developed in vivo.
In a novel rat biofilm model we compared scraping and sonication as methods for dislodging biofilm bacteria.
Twenty plates of steel alloy (5×7×1mm), with a surface roughness (Ra) of 0.35 (0.19–0.51) μm, were inserted into 20 standardised pieces of sheep costae, weight: 1.2 (1.0–1.5) gram. To each bone graft was added 50 μL of a Staphylococcus epidermidis suspension containing 1.4 (1.1–1.7)×104 CFU. Ten Sprague Dawley rats were operated with implantation of the bone graft subfascially on each side of the interscapular region. After two weeks the grafts were excised. The plates were removed from the grafts and rinsed twice in saline. Aliquots of 50 μL were cultured. 10 plates were scraped, followed by vortex mixing of the knife blade; and 10 plates were sonicated at 30 kHz for five minutes. 50 μL of the saline used for a) vortex mixing of the knife blade, and b) sonication, was seeded on agar. After overnight incubation the number of CFU was counted.
The total number of CFU recovered after scraping and sonication were 2(0–13) × 102 and 298(8–878) × 102, respectively (p< 0, 01). Compared to the number of CFU in the rinsing fluid, no increase was observed after scraping. For each plate that was sonicated there was a 38 (3–300) fold increase in the number of CFU.
First, sonication is a superior technique for dislodging biofilm bacteria in an in vivo model, compared to scraping. Secondly, the present experimental model is a promising method for developing biofilm in vivo.
Two-staged exchange arthroplasty with an antibiotic-impregnated PMMA cement spacer in-between two stages has a success rate of 85% to 95% in eradication of infection. Use of vancomycine in high doses has a high potential for complications due to nephrotoxicity.
The aim of this study was to evaluate the results of two-staged exchange arthroplasty in infected hip arthroplasty using low-dose vancomycine-impregnated PMMA cement as an interim spacer between stages.
Thirty-five (20 females, 15 males, average age: 60) patients with a confirmed infected total hip arthroplasty who were treated between 1999 and 2005 were the subjects of the study. In the first stage after removal of the prosthesis and debridement, a spacer made of 40 grams of PMMA cement impregnated with 1 gr vancomycine was placed in the infected joint space. Postoperatively, patients were treated with 6 weeks of intravenous antibiotics in consultation with an infectious disease consultant. When CRP and ESR returned to normal levels, revision surgery with cementless components was performed.
The average follow-up after the second stage was 4 years. The ESR and CRP decreased significantly before the second stage with this treatment protocol (from 81.28 to 17.54 mm/h p< 0.001 and 10.05 to 0.64 mg/dl respectively, p< 0.001). The mean interval between the two stages was 193.3 days. A second debridement was needed in 4 patients (10.8 %) because they did not respond to treatment. Two patients (5.4 %) had recurrent infections after reimplantation and underwent a resection arthroplasty. None of the patients suffered from antibiotic toxicity.
Two-stage exchange arthroplasty using a low dose vancomycine-impregnated cement spacer was an effective method in treating infected hip replacements. With using a lower dose than previously reported, we were able to avoid antibiotic toxicity while effectively treating our patients with the same success rate.
To assess the incidence of infection in cases of Primary Total Knee Arthroplasty with prior steroid injection into the knee joint.
Steroid injection into the arthritic joint is a well-known modality of treatment of arthritic joints. Its efficacy is well-documented. Increased incidence of infection secondary to steroid injection as compared to uninjected joints is reported in recent literature.
A retrospective study was conducted. Four hundred and forty patients underwent Total Knee Replacement by the senior author during 1997–2005 at Wrightington hospital. Ninety patients had intraarticular steroid injection prior to surgery of which 35 patients had injection within 1 year prior to surgery. All patients had at least one year follow-up. Infection rate was assessed by case note, x-rays and microbiology review till last follow-up. One hundred and eighty patients of matched cohort who had Total Knee Replacement without steroid injection were compared for infection rate.
Two cases of superficial infection were noted in the infection group and 5 cases of superficial infection in the non-injection group. No case of deep infection was noted in either group. Statistical analysis showed no significant difference in incidence of infection in either group.
Steroids are useful adjuncts in the management of patients with arthritic joints. This study shows no increased incidence of infection in patients who were given steroid injection prior to arthroplasty.
Culture of tissue samples obtained peri-operatively is ‘the gold standard’ for determining the presence of infection in prosthetic revision surgery. The growth of identical bacterial strains in three or more specimens strongly indicates an infected prosthesis. With routine microbiological culture techniques, identification of different phenotypes of coagulase negative staphylococcus (CNS) will be interpreted as either contamination or a polybacterial infection. At our clinic, different phenotypes of CNS are cultured in approximately 20% of patients operated with a two-stage revision due to a chronic prosthetic infection.
We studied the genotype of different phenotypes of CNS cultured in specimens obtained from prosthetic joints.
We analysed 22 cases, where different phenotypes of CNS were cultured in tissue, and joint fluid specimens were collected peri-operatively. The pre-operative diagnosis was chronic prosthetic infection (n=16), aseptic revision (n=5) and primary prosthesis (n=1). Different phenotypes were assessed by colony morphology and/or antibiogram. Pulsed-field gel electrophoresis (PFGE) was employed to identify and compare the genotypes.
In 16 out of 22 cases (73 %), PFGE unveiled that phenotypically different strains of CNS belonged to the same genotype. Of these 16 cases 7 had different antibiograms. In the other group (6/22), phenotypically different strains of CNS did not belong to the same genotype. In the 16 cases with different phenotypes belonging to the same genotype, gentamicin bone cement had previously been used in 15 cases. In the other group (6/22), gentamicin bone cement had not been used previously in any case (p < 0.01, chi-square test).
Phenotypically different strains of CNS identified by routine microbiological techniques should not be classified readily as contamination or as a mixed bacterial infection in prosthetic surgery. A particular precaution should be taken in the case of patients who had previously been operated on with use of gentamicin-loaded bone cement.
Infection is one of the most disturbing and frightening complications of total knee arthroplasty (TKA). The purpose of the present study was to review the management and outcomes of infected total knee arthroplasty.
The management and outcomes in 71 patients with 71 infected TKA was reviewed. Two-stage reimplantation with 8 weeks of intravenous therapy between the stages was used in 49 patients. Twenty-four patients ended with an arthrodesis using external fixation or intramedulary (IM) nailing. A two-stage technique was used with IM nail arthrodesis. Infections after TKA associated with bone destruction and loss were treated using an antibiotic-impregnated cement rod-spacer. Two patients required amputation: one because of soft tissue necrosis around the knee, another because of recalcitrant infection. In two patients the antibiotic-impregnated cement rod-spacer was chosen as a definitive treatment. The re-infection rate was about 25%. In most cases of reinfection the pathogens were the same, but of higher virulence and resistance. Infection was eradicated in 85% of patients. More than half of patients ended up with a functional TKA (average function score was 86.5 points, average range of motion from 2 to 109 degrees). One third of patients had a solid fusion. The infection could not be eradicated in 15% of patients.
The management and outcomes of infected total knee arthroplasty depend on a rapid and accurate diagnosis. A clear and effective management algorithm should yield favorable outcomes according to well-defined criteria. The two-stage reimplantation is the treatment of choice for chronic periprosthetic knee infection. Knee arthrodesis can be an effective treatment option after the failure of a TKA due to infection.
Gentamicin was described with negative effects on bone formation. Arginin-Glycin-Aspartat (RGD) sequences play a key role in the adhesion of osteoblasts and have proven to improve implant integration. We have already shown a significant reduction in infection rates by a combined gentamicin-hydroxyapatite (HA) and gentamicin-RGD-hydroxyapatite coating in a rabbit infection model for cementless joint prostheses.
The purpose of the study was to assess whether the gentamicin-HA coating had a negative effect on the implant integration and new bone formation, compared to pure HA coating, and whether this could be enhanced by additional gentamicin-RGD-HA coating.
There were 5 study groups (8 animals per group) with 5 different stainless steel K-wires: uncoated, HA coated, gentamicin-HA, RGD-coated, gentamicin-RGD-HA coated. A 2.0 mm K-wire with one type of coating was introduced into the intramedullary canal of the tibia. The tibiae were harvested after 12 weeks and standardised longitudinal and transverse sections were performed to study new bone formation around the implant and implant bone contact. New bone formation and osseointegration of the implant surface was assessed using histomorphometrical methods by computerised semi-quantitative analysis and histological methods.
There were no significant differences between the HA and the gentamicin-HA group although new bone formation and implant bone contact were always higher for the pure HA coating. Additional RGD coating on the gentamicin-RGD-HA coating did not show significant improvement of bone formation and implant integration compared to gentamicin-HA. There was a very similar histological appearance of new bone formation between all groups with very low frequency of giant cells, indicating good biocompatibility.
Gentamicin-HA coating did not have significant negative effects on bone formation and bone implant contact, compared to pure HA coating. In combination with the excellent ability to reduce infection rates, gentamicin-HA coating may have a high interest in cement-less arthroplasty.
Using thermal spraying technique, we developed a novel titanium material coated with hydroxyapatite (HA) containing silver (Ag). In this study, antibacterial activities of the material were examined both in vitro and in vivo.
Two different titanium test pieces were prepared. One is the test piece that was coated by HA containing Ag (HA-Ag) and the other is that was coated by HA only, used as a negative control. Antibacterial activity and efficacy of HA-Ag against Staphylococcus aureus, Escherichia coli, and biofilm-forming methicillin-resistant S. aureus (BF-MRSA) was examined by using the Japanese Industrial Standards test (JIS Z2801). Furthermore, surface area where BF-MRSA was attached and proliferated on the test pieces after 24 hours of incubation was calculated by means of scanning electron microscope (SEM). To investigate the antibacterial activity in vivo, the test pieces were inserted subcutisly into the back of SD rats, and BF-MRSA was inoculated into the inserted pieces. On the 7th day after the inoculation, the numbers of adherent bacteria to the pieces were countered by a sterile cotton-tipped swabs method.
By the JIS Z2801 test, HA-Ag showed 104 to 105 times stronger antibacterial activity than HA against all bacteria tested in this study. SEM studies revealed the HA-Ag coated material had 30 to 50 times smaller area of attached bacteria than control. In vivo study showed that viable bacterial numbers on surfaces of HA-Ag were 1000 times less than control. These results indicated that the HA-Ag coated materials have antibacterial activities both in vitro and in vivo.
Titanium coated with HA containing Ag has a possibility to be a novel antibacterial biomaterial.
The management of post-traumatic bone infections relies on antibiotic therapy and surgical debridement. Antibiotic concentration in infected bone is a major determinant of response to medical treatment.
The aim is to assess glycopeptides, fluoroquinolones and carbapenems diffusion in infected human bone, since they are widely used for treating bone infections.
Twenty-four patients with septic pseudoarthrosis undergoing surgical debridement and treated with glycopeptides/fluoroquinolones/carbapenems iv for > 1 week were studied. Plasma and bone specimens were collected intraoperatively at a mean of 4.8h after antibiotic administration. Antibiotic concentrations were measured by the HPLC-UV method.
Five patients received vancomycin: mean bone concentrations were 2.4mg/L in cortical and 7.1mg/L in cancellous bone, with a bone/plasma extraction of 12% and 36%, respectively.
Nine patients were treated with teicoplanin: bone concentrations were 2.5mg/L for cortical and 8.3mg/L for cancellous bone (14% and 46% of plasma levels).
Five patients received a fluoroquinolone. Ciprofloxacin concentrations were 1.8mg/L in cortical bone and 30.2mg/L in cancellous and newly formed bone (respective bone/plasma ratios 1.06 and 8.4). Levofloxacin concentrations were 0.3 and 2.69mg/L in cortical and cancellous bone, with diffusion rates of 12% and 108%, respectively.
Five patients received a carbapenem. Imipenem diffusion rates were respectively 7.5% and 58.3% for cortical and cancellous bone (bone concentrations 0.09 mg/L and 0.7 mg/L). Meropenem levels were 1.2 mg/L and 5.2 mg/L in cortical and cancellous bone, with respective diffusion rates of 3.6% and 15%.
Both glycopeptides provided concentrations exceeding the MIC of infecting agents, with satisfactory bone diffusion. Fluoroquinolones, especially ciprofloxacin, displayed excellent diffusion. Ciprofloxacin concentrations in cancellous and new bone were far higher than in plasma, suggesting accumulation into highly vascularized tissue. Imipenem had better diffusion than meropenem, but bone levels were under the MIC of susceptible agents. Glicopeptides and fluoroquinolones appear excellent options for bone infections, while carbapenems should be a second choice treatment.
Infection of the ankle joint is a serious problem that can have a debilitating outcome if not identified and treated appropriately.
The purpose of this retrospective study is to present epidemiologic data aimed at better characterising the clinical diagnosis of septic ankle guiding empiric therapy.
All admissions to Los Angeles County+USC Medical Center between 1996 and 2005 were screened to identify patients with ankle infection, shown by a synovial WBC count > 50,000, frank purulence in the joint, or positive synovial culture. Forty-two patients (33 male, 9 female) with a mean age of 44.8 (23 to 67 years) were identified. Twelve out of forty-two patients had indwelling hardware and were excluded from further analysis.
Of the 30 patients with hematogenous septic ankle arthritis, 87% reported ankle pain, 70% ankle swelling, and 50% demonstrated decreased range of motion at the ankle joint. Cultures grew Staphylococcus aureus (43%), streptococci (30%), and gram-negative rods (7%). Twenty-three percent of cases were polymicrobial; no cases of Neisseria gonorrhea were identified. There were 3 cases of M. tuberculosis, and 1 case each of Coccidioides immitis and Aspergillus sp. Forty-four percent of the Staphylococcus aureus were methicillin-resistant (MRSA); no change was observed in prevalence of resistant organisms over time. Only 48% had an elevated WBC count; C-reactive protein and ESR were elevated in 100% of patients. Adjacent osteomyelitis was found in 30% of patients. Open irrigation and debridement was performed in 73% of cases; five patients required multiple surgical procedures and 1 amputation.
Septic ankle arthritis presents non-specifically; a high index of suspicion is essential to ensure prompt identification and treatment. Empiric antibiotic therapy should cover Staphylococcus aureus (including MRSA) and streptococcus. Patients should be evaluated for adjacent osteomyelitis.
In the literature a lot is written about the antibacterial properties that maggots and their secretions are thought to possess, with inconsistencies among different studies. This study investigates the mechanism of the successful clearance of infections in wounds by maggots through examining living maggots and their excretions.
To test the excretions a turbidometric assay was carried out. The sterile excretions were pipetted in different dilutions into a microtiter plate and had bacteria added. Five bacteria were tested, viz. S. aureus, S. pyogenes, E. faecalis, P. aeruginosa and K. oxytoca. After 20 hours the wells were checked. Clear wells presented bacteriolytic activity, whereas cloudy wells presented bacterial growth.
Putting maggots in tubes together with bacterial suspension tested the effect of living maggots. Control tubes contained bacteria only. Same bacteria as ascribed above were used, except for E. faecalis that was changed for coagulase-negative Streptococ. Young maggots (Instar-1) and full-grown maggots (Instar-3) were used, and as a medium for the suspension, Muller Hinton (MH) was used with and without 5% sheep blood. The tubes were horizontally incubated for 16 hours, and every two hours a sample was taken and put onto an agar plate. After 24 hours, the bacterial colonies were counted.
The turbidometric assay showed cloudy wells for all bacteria and dilutions with the less diluted excrete showing the highest stimulation of bacterial growth.
The test with living maggots showed increased bacterial growth as compared to the controls (p=0.001 using the S. aureus). Young maggots stimulated growth more than full-grown maggots (p=0.002 using the S. aureus). Using a more nutritious medium, viz. MH with 5% sheep blood, no difference in growth of bacteria was observed between the tubes with maggots and the controls (p=0.271 using the S. aureus). The other bacteria gave similar results.
This study shows that other mechanisms must be accounted for the clearance of infections in wounds by maggots than their proposed antibacterial properties.
Addition of antibiotics to the bone cement decreases the incidence of infection. However, the antibiotic is only partially released. Ultrasound may increase the antibiotic release and furthermore the effectiveness of the antibiotic might be enhanced by the so-called bio-acoustic effect.
The objective of this study was twofold. The first aim was to evaluate to what extent antibiotic release from bone cement could be increased by ultrasound. The second aim was to investigate the viability of bacteria when antibiotic release from bone cements was combined with ultrasound.
Cylindrical bone cement samples of Palacos R-G (loaded with gentamicin) and Copal (loaded with gentamicin and clindamycin) were insonated and antibiotic release was compared with uninsonated samples. In addition, identical samples were used in combination with cultures of bacteria derived from prosthesis-related infections. The viability of these bacteria was determined with and without ultrasound, using unloaded Palacos R as a control.
There was a trend of increased gentamicin release under influence of ultrasound. Clindamycin release from Copal was significantly increased. Ultrasound alone did not affect bacterial viability, but the application of ultrasound in combination with antibiotic-loaded bone cements reduced both planktonic and biofilm bacterial viability.
The release of antibiotics from bone cement was increased by the application of ultrasound. Antibiotic release in combination with ultrasound increases the antimicrobial efficacy against a variety of clinical isolates. The enhanced efficacy against bacteria in the biofilm mode of growth, especially against a gentamicin-resistant strain, is clinically important with regard to the treatment of infected joint prostheses. Ultrasound may also be applied in the early postoperative period to prevent infections, because planktonic bacteria present in the wound and wound area due to inevitable contamination during surgery can then be more effectively prevented from forming a biofilm.
The main goal is to provide insight into spinal tuberculosis from a Dutch perspective: to establish the size of the problem in the Netherlands, analyse the reasons for misdiagnosis, assess optimal treatment, verify if this is truly optimal, establish the effect of surgery, and find out when surgery is needed.
We made an analysis of the increase in Bone and Joint Tuberculosis (BJTB) in the Netherlands during the recent years. Between 1993 and 2000 a total of 532 cases of BJTB were found. Univariate analysis showed that the increase in incidence was restricted to non-Dutch people from endemic areas. It is important to note that only 15% of BJTB patients in our series also suffered from pulmonary TB. In our study a lengthy delay by both patients and doctors was found for BJTB (mean period 32 weeks), probably explained by a low index of suspicion and declining expertise.
We report a previously undescribed misdiagnosis and subsequent mistreatment with radiation for tuberculosis of the spine in two patients.
Both patients were misdiagnosed as having malignancies, without sufficient material for histological and culture examination. Both received radiotherapy, both experienced growth of the lesion, and in one of the patients the neurological deficit increased and did not reverse after initiation of the proper TB treatment. The main reasons for misdiagnosis of spinal TB are low incidence, low index of suspicion, declined expertise, and accepted failed biopsy. Radiotherapy locally aggravates tuberculous spinal lesions.
There is no uniform advice in the literature regarding the duration of chemotherapeutic treatment for spinal tuberculosis. A review of the literature from 1978 (after the introduction of Pyrazinamide) to 2000 was performed.
The relapse rate of 2% for the patients that had > 6 months chemotherapy is low, as is the relapse rate of 0% for patients with 6 months treatment. We concluded that the duration of chemotherapy for spinal tuberculosis can be 6 months.
Subtherapeutic concentrations intralesional may result in selection of a resistant bacterial population and lead to treatment failure.
Intralesional drug concentrations were below Minimal Inhibitory Concentration (MIC) values in 0/15 patients for ISO, 2/13 for RIF, and 8/9 for PYR. In 5/8 patients receiving all three drugs both RIF and PYR had Cmax:MIC ratios < 4, indicating intralesional subtherapeutic drug levels.
Drainage is advised as additional therapy for patients with pleural effusion or psoas abscesses; it reduces the intralesional bacterial load and shortens the time of resolution of the lesions.
A Cochrane systematic review was performed with the aim to compare chemotherapy to chemotherapy plus surgery in the treatment of spinal TB.
There were no statistically significant differences between the treatment and control group for kyphosis and bony fusion. There were no significant differences in neurology, but some patients from the control group had an operation (change of allocated treatment) for persisting deficit. Chemotherapy is the critical factor in the management of tuberculosis of the spine. Routine surgery is not indicated. Surgery has a role in subgroups of patients for orthopaedic or neurological reasons: large or progressive kyphosis, and progressive or persistent neurological deficit.
We evaluated radiographic and clinical parameters as early predictors for the final kyphosis angle in spinal TB to identify the patients at risk for developing severe or progressive kyphosis.
Univariate analysis revealed no significant independent predictors. Multivariate analysis showed that bone loss < 0.3 in combination with a thoracic localisation indicated 97% chance of favourable outcome. A simple and clinically useful algorithm for early prediction of kyphosis in spinal TB is presented.
The use of polymethylmethacrylate (PMMA) bone cement loaded with antibiotics has become increasingly common in orthopaedic surgery. However, bacterial resistance in antibiotics is an increasing and emerging problem. PMMA bone cements containing different antibiotics, such as gentamicin plus vancomycin may be effective in prevention and treatment of infections (particularly from MRSA and MRSE).
The purpose of this study was to determine the in vitro elution characteristics of gentamicin and vancomycin when combined in acrylic cement.
Three groups of ten cement disks were prepared. Group I (control group) contained 0.5g of gentamicin per 40-g packet of Palacos-R+G powder. Group II contained 0.5g of gentamicin and 1g of powdered vancomycin and group III contained 0.5g of gentamicin and aqueous solution of vancomycin. Each cement disc (25mm x 20mm) was immersed in a 50-mL bath of normal saline at 37oC. Samples were taken at specific sampling intervals (1, 3, 7, 15, 30, 60, 90, 120, 150, 180 days). Antibiotic concentrations were measured using fluorescence polarisation immunoassay.
With regards to gentamicin release, high but rapidly decreasing antibiotic levels were detected within the first week and low concentration after the first month. Samples from Group II eluted significantly more gentamicin (120%–20% during the first month). The influence on the gentamicin release was significant but minor when aqueous solution of vancomycin (Group III) was added. With regards to vancomycin release, high antibiotic levels were detected within the first 3 days and low concentrations after the first week. Cement samples from Group II eluted significantly more antibiotic in comparison with samples from Group III.
Bone cements loaded with combinations of gentamicin and vancomycin are more effective in releasing gentamicin than bone cements with gentamicin as a single drug. Powdered vancomycin in cement samples has better elution characteristics in comparison with aqueous solution of vancomycin.
The use of megaprosthesis presents a major advancement in orthopaedic oncology in the treatment of malignant bone and soft tissue tumours.
In the present study, we retrospectively analyse the complication rate of limb salvage surgery with megaprosthesis due to malignant tumours treated in our unit.
From 1997 until 2006, 64 patients (37 men, 27 women), aged between 16–78 years old (mean 43.3), have been treated with megaprosthesis insertion. The diagnosis was metastatic bone lesions in 26 patients, osteosarcoma in 14, chondrosarcoma in 14, soft tissue sarcoma with osseous involvement in 3 (2 synovial sarcoma and 1 MPNST), malignant giant cell tumour in 3, angiosarcoma in 2, Ewing sarcoma in 1, and revision of a failed reconstruction in 1 patient. Lower extremity reconstruction included proximal femur (30 patients), distal femur (19), proximal tibia (3) and total femur replacement (4). Upper extremity procedures were proximal humerus (7 patients) and distal humerus reconstruction (1).
Sixty patients were available for follow-up (minimum 1 year, mean 4.2 years). The following complications were encountered: periprosthetic fracture (1 patient), deep infection (4), superficial wound infection (6), local recurrences (2), hip dislocation (3), knee extensor apparatus failure (2), skin necrosis, (3) unsuccessful vascular reconstruction (1). The deep infection led to hip disarticulation in 1 patient and Tikhoff-Linberg resection in 1 patient with proximal humerus prosthesis. A rare case of bone leismaniasis was also encountered (treated conservatively).
Limb salvage surgery is the mainstay of treatment in malignant musculoskeletal tumours. Special megaprosthesis has been developed for this purpose. Survival rate is substantially less than common prosthesis; the complication rate is increased, especially regarding wound healing complications and infection. Adverse prognostic factors are:
a) advanced age, b) the amount of soft tissues that need to be excised, c) prolonged surgical time, and d) reconstruction about the knee.
Distal tibia and ankle sepsis can threaten the viability of the limb. We present the management protocol and results in 37 patients with chronic infection of the distal tibia and ankle, followed up for a mean of 4 years.
The mean age was 45.6 years. Host type A were 21 patients, type B were 9, and type C were 7 patients. Treatment included radical debridement, multiple cultures sampling and local antibiotic application. Twenty seven patients required bone stabilisation, whereas 3 host C patients were amputated. Soft tissue coverage included 5 free muscle flaps, 3 soleus flaps and 5 pedicle fasciocutaneous local flaps. Bone defects of a mean of 6.3 cm (3–13cm) in 20 cases were treated with distraction histogenesis (13 cases) or the free fibula vascularised graft (7 cases).
Mean hospitalisation time was 26.2 days (host-A: 19.6 vs. host B/C: 32.2, p=0.036). Host-A patients required 2.3 operative procedures whereas host-B/C 3.9 (p=0.01). Union occurred in 26/27 (96%) of cases requiring fixation (one ankle arthrodesis revision/host-B patient). External fixation frames were kept in situ for a mean of 31.7 weeks (12–85). Mean leg length discrepancy was 0.6 cm. Ankle arthrodesis was performed in 7 patients (5% among host-A patients vs. 38% among B/C). Independent ambulation was achieved in (35/37) 95%. All patients were satisfied with the result. Bacteriology revealed Staph. aureus in 71%, whereas 38% were polymicrobial (7% in host-A vs. 88% in B/C patients, p< 0.001). Infection recurrence occurred in 5.4% (none in host-A vs. 13% in B/C patients, p=0.03), whereas the overall complication rate was 43% (24% in host-A vs. 75% in B/C patients, p=0.02).
Functional limb salvage without leg length discrepancy was possible in 92% of cases. Systemically compromised patients required longer hospitalisation, more operative procedures, had frequently polymicrobial infections and more complications.
Successful treatment of prosthetic joint infections (PJIs) requires surgical intervention and prolonged antimicrobial therapy (AT), although the most suitable management has not been clearly defined yet. The aim of the study is to review our experience in the management of AHPJIs.
From 01/01/2004 to 31/12/2006 all patients with PJIs were prospectively evaluated in 8 Spanish hospitals by the REIPI. We focused here on AHPJIs. Diagnostic of infection was based on clinical-microbiological evidence.
Forty-nine patients, 30 (61.2%) women, median age: 75.35 years (range: 31–92), were diagnosed of AHPJIs: 22 (44.8%) hips, 26 (53%) knees and 1 (2%) elbow implants. Following total joint replacement our patients had a median infection-free period of 4.9 years (range 0.3 to 18.7). The comorbidities were: 9 (18.3%) rheumatoid arthritis, 7 (14.3%) diabetes, and 6 (12.2%) chronic renal failure. Clinical features were acute in all cases: pain 100%, inflammatory signs 75.5%, and fever 70%. In 27 (55%) of the cases a distant previous infection caused by the same microorganism could be identified. The etiology was: S. aureus 18 (36.7%), streptococcal infections 13 (26.5%), coagulase-negative staphylococci 2 (4%), gram-negative bacilli 11 (22.4%), anaerobes 2 (4%), and mixed infections in 3 (6.1%) cases. Thirty (61.1%) patients underwent early drainage/debridement with retention of the implant, 11 (22.4%) two-stage replacement, 6 (12.5%) arthrodesis, 1 (2.1%) resection arthroplasty, and 1 unknown. Patients were treated with specific AT (median duration of 10.6 weeks) according to the isolated microorganism. At 1 year follow-up 25 (51%) were cured, 7 (14.3%) relapsed after a conservative approach (3 required an arthrodesis and 1 a two-stage replacement), 5 (10.2 %) died and 5 (10.2%) had a re-infection; in 7 the evolution was unknown.
AHPJs can be successfully treated in most cases with surgical debridement plus an antibiotic course. If a relapse is observed, removal of the prostheses could be necessary.
Although linezolid has been used in the therapy of osteoarticular infections (OI), there is little information about its effectiveness and safety in prolonged therapy for OI.
Therefore the aim of our study was to assess the effectiveness and tolerability in OI and retrospectively evaluate multi-resistant gram-positive OI treated with linezolid 600 mg bid orally.
Between January 2003 and January 2007, 20 patients (10 men, mean age: 65 years) with 23 episodes of OI (19 of them associated with implants including 16 prosthetic joints) were treated with linezolid. In all but one episode, vitamin B6 was administered. Five were diabetic and 1 had renal insufficiency. All but two cases had infections due to multi-resistant coagulase-negative staphylococci. The median duration of therapy was 12.3 weeks (range 4–36 weeks). In 9 episodes the implant was removed. At the end of the therapy, response was observed in 22/23 (95.6%) of the episodes, and at the follow-up 10 relapses occurred (median duration: 1 month) resulting in an overall successful rate of cure of 12/23 (52.2%). The cure rate in episodes with and without implant removal was 6/9 (66.7%) and 3/10 (30%), respectively, while in the cases without implant 3/4 (75%). Adverse events that required drug discontinuation were observed in 10 (43.5%) episodes: anemia in 6/10 (60%), gastrointestinal in 6/10 (60%), lactic acidosis in two, teeth pigmentation in two and optic neuritis in one. Risk factors associated with secondary effects were: older age, diabetes mellitus and renal insufficiency. One patient developed anemia after one month; linezolid was stopped and restarted with vitamin B6 and no anemia was observed after 9 months of therapy.
Linezolid may be useful in multi-resistant gram-positive OI, especially when the implant is removed. However, with prolonged therapy, side effects are common, thus close monitoring for severe complications is needed.
Although bovine carriers of antibiotics are generally accepted in the treatment of local infections, a literature search in PubMed, Medline and Embase up to April 2006 did not reveal any information on the human pharmacokinetics on Garacol®, a bovine carrier containing the equivalent of 130 mg gentamicin sulphate, on the market since 1995. The purpose of this study was to describe the human in vivo pharmacokinetics of Garacol®.
A cohort of 19 consecutive patients with an acute periprosthetic infection to which 2 to 5 fleeces were applied in each case.
Initially, the concentration in blood increased to 3.2–7.2 mg/L depending on the number of fleeces that were applied. The serum peak concentrations resulted in peak/MIC ratios of 2.5–36 for P. aeruginosa, S. aureus and Klebsiella spp. Peak gentamicin levels in the exudate are bactericidal for several days, even for gentamicin-resistant micro-organisms. Subsequently, the serum values decreased almost linearly below 0.3 mg/L in 18 to 62 hours. After 24 hours the gentamicin serum levels dropped below the threshold for toxicity of 2 mg/L. Comparison is made between the difference in pharmacokinetic behaviour of the Garacol® drug with Septocoll® and conventional and mini PMMA beads.
The conclusion is that collagen-loaded fleeces may be useful as an adjuvant treatment of implant-related infections.
Foot osteomyelitis is a common problem for which management is variable and few guidelines exist.
To present our treatment protocol and the results in 36 patients (20 men, 16 women, mean age: 49.5 years) with osteomyelitis distal to the ankle, followed up for 17.6 months (range: 3–64).
Bone infection involved toes (n=4), lesser metatarsals (n=11), hallux (n=3), midfoot (n=4), calcaneus (n=9), whereas 4 cases presented as generalised osteomyelitis. Postoperative infection was the cause in 10 cases. Eleven patients were classified as host-type A, 14 as B and 11 as C. A draining sinus was present in 28 cases. The treatment protocol included surgical debridement, the bead-pouch technique for local antibiotic administration and closure primarily (n=27), or by secondary healing (n=5), skin graft (n=2), local fasciocutaneous (n=1), or free vascularised muscle flap (n=1). Systemic antibiotics according to cultures were administered for 5–7 days. Generalized Charcot osteomyelitis was an indication for amputation.
Mean hospital stay was 13.8 days (range 1–34) and 2.7 (range 1–7) surgical procedures per patient were recorded. Infection control was achieved in 26 cases (72.2%), whereas amputations were performed in 10 cases (27.8%). Below-knee amputation was undertaken in 4 host-type C patients with Charcot osteomyelitis of the foot. Ray amputations were performed in 4 diabetic feet. Six amputees were classified as host-C and 3 as host-B. One host-type A patient with recurrent post-traumatic toe osteomyelitis, underwent a distal phalanx amputation as definitive solution. Amputation rates were 55% among host-C, 22% among host-B and 9% among host-A patients (p< 0.001).
Diffuse foot osteomyelitis in systemically compromised patients resulted in high amputation rates. Better results were obtained in non-compromised hosts and focal osteomyelitis.
The objective of the present study is to analyse the clinical, microbiological, and therapeutic features of patients with infective spondylodiscitis (ISD), who were followed up in our Outpatient Bone Infection Clinic.
We retrospectively studied the epidemiological and clinical characteristics of all patients diagnosed with ISD from January 1998 to December 2006. Data were extracted from an electronic data base registry and patients’ files.
Sixty patients either with spontaneous (n= 42, 70%) or postoperative (n= 18, 30%) ISD were evaluated. Population mean age was 56 years, 33 (55%) were male and 27 (45%) were female. The infection was localised in the lumbar (78%), thoracic (18%) or cervical (4%) spine. Predominate symptoms were pain (87%) and fever (50%). Fistula was observed exclusively in postoperative ISD (45%). In spontaneous ISD, the major causes were Brucella spp (33%), gram positive cocci (12%), gram negative bacteria (14%), Mycobacterium tuberculosis (7%), while in 33% of cases no pathogen was detected. In postoperative episodes of ISD the major causes were gram positive cocci (45%), gram negative bacteria (30%) and polymicrobial infection was documented in 22% of cases while in 25% of cases no pathogen was detected. Based on clinical, laboratory and imaging (especially MRI) data, treatment was individualised. Most patients (88%) received a combined antimicrobial treatment. Patients with spontaneous pyogenic/brucellosis or tuberculous/post-operative ISD received treatment for a median duration of 8/12/10 months and the response rate was 84%/81%/55.5%, respectively. Surgery was necessary in 40% of postoperative ISD cases for healing, while only one spontaneous case required a surgical intervention.
ISD is more frequently localised at the lumbar level. Long term combination antimicrobial treatment may be essential. Surgery may be required in iatrogenic cases in the presence of foreign bodies.
Flaps constitute an integral part of the treatment of soft tissue and skeletal infections of the extremities, focusing on the coverage and augmentation of the local biology.
In a 6-year period, a total of 33 septic defects of the upper (6) and lower (27) extremities were treated with 4 free and 29 pedicled flaps, after extensive surgical debridement of the septic site. In the lower extremity, treatment included 3 free (2 latissimus dorsi and 1 serratus anterior), and 24 pedicled flaps (5 heads of gastrocnemius, 7 soleus, 1 abductor hallucis, 9 reverse fasciocutaneous, 1 combined medial head of gastrocnemius and soleus and 1 extensor longus hallucis) for 3 cases of soft tissue sepsis and 24 septic defects of the skeleton. In the upper extremity, 1 free vascularised fibular graft (combined with muscle-skin) and 5 pedicled flaps (2 homodigital, 1 heterodigital, 1 cross-finger, 1 periosteal) were used for 3 soft tissue and 3 skeletal septic defects. All but one flaps of the lower extremities were covered with split thickness skin (simultaneously or within 7 days), whereas flaps of the upper extremity included skin in all cases.
Three flaps (2 reverse fasciocutaneous and one soleus) were revised (with latissimus dorsi, serratus anterior and extensor longus hallucis flaps respectively) in a mean period of 4 months due to persistent infection and 4 skin grafts were revised due to superficial infection. In a minimum follow-up period of 9 months (9–60 months) full coverage of the defect and treatment of infection was accomplished in all patients, resulting in a good functional and aesthetic outcome. Except for 2 patients, all were able to walk and use their extremity and returned to previous activities.
The use of flaps in the treatment of septic skeletal or soft tissue defects leads to a functional upper or lower extremity and successfully prevents amputation.
Our question is whether it is possible, by means of (18)F Fluorodesoxyglucose-Positron-Emission-Tomography-Computertomography (FDG-PET-CT) data created in line with the diagnostics of chronic osteitis, to undertake a navigation for the treatment of the focus of osteitis.
Within the scope of an experimental examination, the focus of osteitis at an animal bone model (pork) has been simulated. The animal bone was prepared with injection of FDG via three 2.5 mm drill holes into the bone marrow. For further investigation the FDG was injected undiluted, mixed with pigment and with radiopaque contrast medium.
Using FDG, a PET-CT dataset at the primed animal bone model has been created. For matching the position of the artificial FDG-focus and the virtual displayed position two cortical screws were placed close to the FDG-focus in the cortical bone. Two X-Ray shots in different positions were taken from the region of interest. The referencing of the dataset was achieved with CT-fluoro-matching. Finally, the accuracy of the image of the navigated instrument on the navigation display has been compared with the optical controlled actual placement of the simulated position of the focus of osteitis. The bone was sawed for the final check of the position of the FDG spot in relationship to the anatomical landmarks.
The examination demonstrated that with the available navigation system a PET-CT dataset could be identified. The matching of the CT-dataset with the geometry of the animal bone model was realised with CT-fluoro-matching software.
The verification of the image accuracy on the navigation screen did not show any deflection of the actual placement of the navigated instrument, because the position of the simulated focus of osteitis through the drilled canal was known. The experimental examination described above showed that PET-CT data can be imported into a conventional optical navigation system and can be edited for referencing purposes. It was possible to match the CT-dataset with the fluoroscopic images of the image intensifier. The optical verification of the accuracy did not show any deflection of the displayed position of the navigated instrument compared to the actual placement of the simulated focus of osteitis. The investigation shows sufficient threshold of the animal bone for visualisation with the navigation system.
Since the PET-CT data provide evidence about the activity of a pathological focus, in addition to the information about localisation, the navigated rehabilitation of foci of osteitis in long hollow bones appears possible. For successful treatment and salvage of chronic osteitis the implementation of navigated surgical tools can reduce the dimension of the surgical approach and damage of bone without reduction of the surgical goal.
Further clinical applications must determine whether the possibilities established experimentally can be implemented effectively in practice.
Despite the in-depth research into the treatment of acute septic arthritis of the knee, the morbidity and mortality are still significant.
The purpose of our study was to evaluate the efficacy of a treatment protocol including arthroscopic irrigation and debridement in resolving septic arthritis of the knee.
During a 6-year period, 18 patients presenting with septic arthritis of the knee were included in this study. In 10 cases, septic arthritis occurred after knee arthroscopy, in 2 after open trauma, in 2 more after joint aspiration or injection; there were 2 hematogenous infections and 2 following contiguous spread from an adjacent site. The patients were treated with an arthroscopic debridement protocol consisting of (1) arthroscopic debridement and synovectomy, (2) suction drainage for 24 hours, (3) repeat arthroscopy for persisting clinical and laboratory findings and (4) antibiotics IV for four weeks and per.os. for two months (ciprofloxacin – rifampicin). The onset of the symptoms presented 18.2 days in average after the cause. The patients complained of swelling (18/18), fever ~39° C (16/18), stiffness (13/18), pain (12/18), erythema (6/18) and weakness (6/18). Arthroscopic drainage (average 1.5 procedures) was performed at an average of 8.4 days from the initiation of the symptoms. Laboratory data revealed elevated ESR (erythrocyte sedimentation rate) (average 68.9), CRP (average: 10.9) and WBC (average: 8894.3).
The mean follow-up period was 3.5 years. Cultures from knee joint aspirations were negative in 9 cases. Five knees were infected with Staphylococcus aureus, 2 with Staphylococcus epidermidis, 1 with Escherichia Coli and 1 with multiple organisms. One month after the last arthroscopic debridement, the ESR and CRP levels were normalised in all cases. Lysholm scores averaged 91. Most of the patients (15/18) returned to their pre-infection level of functioning. Overall success in clinical eradication of infection was 100%.
Our conclusions are:
early aggressive arthroscopic debridement as part of a treatment protocol can be an effective treatment option, time is a crucial factor, and the earlier the arthroscopic debridement is performed, the better results are obtained.
Most of the studies in the literature identify spondylodiscitis as a challenge for the physician: symptoms are not specific and sub-acute/chronic presentation is common. The question of when surgery is indicated is a frequent matter of debate. We want to present and validate our flow chart for spinal infections diagnosis and treatment.
A retrospective review of 128 cases of spinal infections presenting over a 10-year period was performed. Medical records, imaging (X-Rays, MRI with gadolinium, Ga-67 and Tc-99 bone scan), laboratory test and bacteriology results of 128 patients from 1997 to 2006 were reviewed.
The average age of presentation was 55 years (median age: 61 years, range: between 1 and 88 years) of 53 females and 75 males. Only one level was interested in 22% of the cases. The cervical spine was affected in 6% of cases, the thoracic spine in 37%, and the lumbosacral spine in 57%. Soft tissues have been affected in 16% of the patients. CT guided trocar biopsies were performed in 80 patients, incisional biopsies in 10 patients, and excisional biopsy in 1 case. No complication occurred. The most represented microorganisms which were identified were Staphylococcus Aureus and Mycobacterium Tuberculosis. Conservative treatment alone (antibiotic therapy and bracing) was performed in 84 cases out of 128 (66%); Forty-four patients with either neurologic compromise or mechanical instability or those who were unresponsive to drugs and immobilisation were submitted to surgical treatment.
Late diagnosis may lead to spinal deformities, prolonged hospital stay and more expensive management of the patient. Appropriate treatment usually brings to resolution even if spinal infections are rare and often misdiagnosed. We suggest an easy-to-follow flow-chart for the diagnosis and treatment of spinal infections.
The accurate differentiation of aseptic loosening from periprosthetic infection in the painful hip prosthesis is a major clinical challenge. FDG-PET imaging has shown great promise in various clinical settings for detection of infection. This prospective study was designed to determine the efficacy of FDG-PET imaging in the assessment of patients with painful hip prosthesis.
One hundred and thirteen patients with 127 painful hip prostheses were evaluated by FDG-PET. Approximately 60 minutes after the intravenous administration of FDG images of the lower extremities were acquired using a dedicated PET machine. FDG-PET images were interpreted by experienced nuclear medicine physicians. Images were considered positive for infection if PET demonstrated increased FDG activity at the bone-prosthesis interface of the femoral component of the prosthesis. Surgical findings, histopathology, and clinical follow-up served as the “gold standard”.
FDG-PET was positive for infection in 35 hips and negative in 92 hips. Among 35 positive PET studies, 28 were proven to be infected by surgical and histopathology findings as well as follow-up tests. Of 92 hip prostheses with negative FDG-PET findings, 87 were proven to be aseptic. The sensitivity, specificity, positive and negative predictive values for FDG-PET were 0.85 (28/33), 0.93 (87/94), 0.80 (28/35), and 0.95 (87/92), respectively. The overall accuracy of FDG-PET in this clinical setting was 90.5% (115/127).
The results demonstrate that FDG-PET is a highly accurate diagnostic test for differentiating infected from non-infected painful hip prosthesis. Therefore, FDG-PET imaging is considered the study of choice in the evaluation of patients with suspected hip prosthesis infection.
Periprosthetic infection (PPI) remains the most dreaded and difficult complication of total joint arthroplasty. Although there is no definite diagnostic test for PPI, synovial leukocyte count and neutrophil percentage have been reported to have high sensitivity and specificity. However, leukocytes and neutrophils introduced into the joint during a traumatic aspiration can skew results and undermine the predictive value of this diagnostic test. This study intends to determine the diagnostic value of implementing a corrective formula frequently used in traumatic spinal taps to adjust for serum leukocytes introduced into the joint fluid during a bloody tap.
We conducted a review of all TKA aspirations of infected and non-infected patients performed at our institute from 2000 to 2005.
The following inclusion criteria were used:
(a) a red cell count (RBC) was performed on the aspirate, and (b) a blood white cell count with differential was done within one week of aspiration.
Patients with inflammatory arthropathy or those who underwent reimplantation after PPI were excluded. Strict criteria for diagnosis of PPI were used. We previously determined at our institute the cut-off values for fluid leukocyte count (> 1760 cells/μl) and neutrophil percentage (> 73%).
The adjusted fluid leukocyte counts were calculated using the following formula:
Wadjusted = WBCobserved – [(WBCblood * RBC-fluid/RBCblood)] predicted.
A similar formula was implemented to calculate the adjusted absolute neutrophil counts.
Our cohort included 73 infected and 32 aseptic total knee arthroplasties that fulfilled the above criteria. After correcting for introduced red blood cells, cell counts of 3 infected patients dropped below the cut-off value, while the remaining 70 maintained a high cell count. However, the 3 infected patients had initial cell counts below our reported cut-offs. Of the 32 non-infected patients, 10 patients had false positive cell counts due to the presence of extremely high numbers of blood RBC. Five of the 10 false positive aspirates successfully corrected to levels below the thresholds used to diagnose infection. The aspirates that corrected had a greater number of introduced RBCs, an initial higher cell count, and 20 times more fluid WBC deducted from the initial cell count.
The corrective formula can safely adjust for RBC found in a traumatic tap and detect false positive results among non-infected TKA without compromising the diagnosis of infection. Adjusted aspirates of non-infected TKA can be expected to decrease below zero due to one of the following: adherence of the introduced systemic WBC to the joint synovium, greater rate of lysis of the introduced systemic WBC compared to the systemic RBC, laboratory errors in performing fluid cell counts.
The differential diagnosis of pain after total knee arthroplasty (TKA) should always include periprosthetic infection (PPI). The current diagnostic tools vary in sensitivity, specificity, and predictive value. Currently there is no test with an absolute accuracy for diagnosis of PPI. Furthermore, cost effectiveness of investigations has become an important issue in recent years as increased expenses can place an unnecessary heavy burden on the medical system.
We retrospectively evaluated 296 patients who underwent revision TKA at our institution during 2000–2005 and had preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) performed. The criteria used for diagnosing infection were a positive intraoperative culture on solid media, presence of an abscess or sinus tract that communicated with the joint, positive preoperative aspiration culture, and/or elevated fluid cell count and neutrophil differential of the aspirated fluid. The sensitivity, specificity, and predictive values of ESR and CRP were determined. Combinations were performed in parallel that necessitate both tests to be negative to rule out infection. The cost of each serological test was compared to that of other commonly used screening modalities.
One hundred and sixteen patients (39%) were classified as infected and 180 patients (61%) were considered non-infected. The sensitivity, specificity, positive predictive value, and negative predictive value for the ESR were: 91%, 72%, 68%, and 93%. The sensitivity, specificity, positive predictive value, and negative predictive value for the CRP were: 94%, 74%, 70%, and 95%. The sensitivity and negative predictive value for the combined studies were 96% and 95%, respectively. However, five infected patients (4%) had a normal
ESR and CRP. An organism was cultured on solid media in 4 of the 5 cases. ESR and CRP were the least costly of all the preoperative tests including radionuclide imaging and joint fluid analysis. ESR and CRP are important preoperative tests in diagnosis of PPI and their ability to clench the diagnosis in the majority of cases should not be underestimated. When combined, these simple serological tests have improved sensitivity and negative predictive value to rule out infection.
Serological tests including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are frequently used in the preoperative workup to screen for periprosthetic infection (PPI) in total hip arthroplasty (THA). The cut-off points reported in the literature are arbitrarily chosen by investigators. Similarly, the values used in laboratories to distinguish elevated results vary from one institute to another. Therefore, we intended to define the appropriate cut-off points of ESR and CRP that can be used to differentiate infection from aseptic failure of THA.
A review of our joint registry database revealed that 515 THA revisions (131 infected cases) were performed during 2000–2005. Intraoperative samples for culture were taken in all cases. The criteria used for diagnosis of infection were a positive intraoperative culture on solid media, presence of an abscess or sinus tract that communicated with the joint, positive preoperative aspiration culture, and/or elevated fluid cell count and neutrophil differential of the aspirated fluid. Non-infected patients with confounding factors that can elevate ESR and CRP including collagen vascular disease, inflammatory arthropathy, malignancy, and urinary tract infection were excluded. Receiver operator curves were used to determine the ideal cut-off point for both ESR and CRP.
The mean value of ESR in the infected group (77mm/ hr) was significantly higher compared to that of the non-infected cohort (29mm/hr) (p=0.0001). Similarly, infected patients presented with a greater mean CRP (9.8 mg/dl) than their non-infected cohort (1.48 mg/ dl) (p=0.0001). The infection threshold for ESR was 45mm/hr with a sensitivity of 85% and specificity of 79%, while the optimal cut-off value for CRP was defined as 1.6 mg/dl which yielded a sensitivity of 86% and specificity of 83%.
The optimal threshold values we determined are higher than the arbitrarily chosen values cited in the literature for ESR (30mm/hr) and CRP (1mg/dl). Although it has been previously reported that the sensitivity and specificity of CRP are far greater than that of ESR, we found that the two tests have comparable diagnostic value.
The accurate diagnosis of periprosthetic infection poses a challenge to the clinician and the imaging specialist alike. In recent years, FDG-PET imaging has shown great promise in the evaluation of occult infection at various anatomic sites. The purpose of this investigation was to determine the accuracy of FDG-PET imaging in diagnosing periprosthetic infection associated with total knee arthroplasty.
Sixty eight painful knee prostheses were referred for further evaluation with FDG-PET imaging. Approximately 60 minutes after the intravenous administration of FDG, PET images of both knees were acquired and interpreted by experienced nuclear medicine physicians. PET images demonstrating increased FDG activity at the bone-prosthesis interface were considered infected. Final diagnosis was made on the basis of surgical findings, histopathology, and clinical follow-up.
FDG-PET correctly diagnosed 19 of the 22 infected cases for a calculated sensitivity of 86.4% (19/22). FDG-PET correctly predicted the absence of infection in 38 of 46 aseptic knee prostheses for a calculated specificity of 82.6% (38/46). The negative and positive predictive values for FDG-PET imaging in this setting were 92.7% (38/41) and 70.4% (19/27), respectively. The overall accuracy of FDG-PET imaging was 83.8% (57/68). FDG-PET was indeterminate in three cases which were not included in this analysis.
These results demonstrate that FDG-PET is a useful diagnostic tool for the evaluation of possible infection associated with knee arthroplasty. Considering the large number of subjects who undergo total knee arthroplasty and the sizable fraction who develop complications following surgery, the impact of FDG-PET imaging could be substantial. Examination of a larger number of patients with painful knee prostheses will further clarify the merit of this powerful technique in this clinical setting.
Currently two-stage resection arthroplasty is the preferred method for surgical treatment of periprosthetic infection in North America. However, the success of this treatment strategy has varied from 54% to 98% based on previous reports. The exact reason for this variation in outcome is not known. The purpose of this study was to determine the efficacy of this treatment modality and delineate patient risk factors that result in recurrent infection and failure.
During the period of this study (2000–2005) 77 patients with an infected THA were treated at our institution. Fifty-four patients underwent two-stage exchange arthroplasty while the remaining 22 failed to have the second stage reimplantation due to ill health. The latter 22 were excluded from the analysis. All patients were followed up prospectively for at least two years after reimplantation. Detailed data including demographics, comorbidities, surgical history, and medication intake was collected. Intraoperative data, organism profile, and complications were also documented. Failure was defined as patient requiring additional surgical procedure for control of infection or loosening.
Two-stage exchange arthroplasty successfully eradicated infection in 36 patients (67%) without need for further treatment. Seven patients (13%) had recurrent infection that necessitated resection arthroplasty. Eleven (20%) patients required irrigation and debridement for postoperative purulent drainage which successfully treated infection in 8 of the cases. The remaining 3 patients failed and required resection arthroplasty. Three additional patients had early loosening of components and required revision arthroplasty. The exact cause of loosening in these patients could not be determined and despite lack of isolation of organisms infection was suspected. Multivariate analysis identified previous medical comorbidity and postoperative allogenic transfusion as risk factors for failure.
Current strategies to treat periprosthetic infection remain imperfect. Two-stage exchange arthroplasty with all its inherent problems and inconveniences imparted a modest success in treatment of PPI at our high volume specialized center. With the increase in the number of virulent and resistant organisms, and the rise in arthroplasties being performed in infirm patients with medical comorbidities the success of this procedure is likely to be jeopardized. Novel treatment modalities to combat this dreaded condition is needed.
Infection of the rear foot and ankle joint often leads to destruction of the bony structures leaving amputation as the only reasonable choice. New techniques using antibiotic impregnated bone grafts have proven efficient even under extreme circumstances. We report of their first application in apparently hopeless cases of rear foot infection.
Between 2004 and 2006 eight patients were operated because of florid infection of a severely destroyed rearfoot. In all cases the pre-treating surgeons suggested amputation below the knee as the only remaining possibility, which was refused by the patients. There were 3 men and 5 women. All patients had multiple surgery (min. 4, max. 72). The duration of infection was between 2 and 26 years. Diagnoses were: 4 St.p. open fracture, 2 Neuropathy, 1 Immunosuppression (kidney X), and 1 Rheumatoid arthritis.
Preoperative diagnostic measures included MRI and Bone Scans, localising the sites of infection. We performed radical debridement of all infected areas, intensive pulsed lavage, filling of defects with antibiotic bone compound (ABC) and stabilization using screws (4x) or the Ilizarov device (1x), respectively. Wounds could be closed primarily in 7 cases; in one case a fasciocutaneous suralis flap was necessary for closing. All patients were followed prospectively with a minimum period of 3 months and a maximum of 3 years.
Wound healing was completed uneventfully within 3 weeks. Surgery was always followed by a period of more than 6 months without any signs of infection. Re-intervention because of recurrence was necessary in 4 cases, whereas during all operations conditions were markedly improved compared to the foregoing intervention. So far 2 patients required 4 re-revisions of which one is awaiting a fifth revision, 1 patient one re-revision, and 1 patient decided to have the leg amputated. Six cases could be supplied with a custom-made shoe and were fully weight-bearing without pain or sign of infection at the last follow-up.
Reconstruction of the infected rearfoot is feasible even under extremely unfavourable conditions using antibiotic impregnated bone grafts. Fifty percent of cases may expect long-standing salvage with a weight-bearing limb. The other 50% must expect repeated surgery. It may be discussed, whether amputation in such cases could provide for a more favourable situation. However, we do believe that the decision for amputation shall be the sole decision of the patient. As long as the patient wants to keep his limb, being aware of all consequences thereafter, the surgeon is obliged to maintain the function of the foot as well as possible. Reconstruction with ABC seems to offer a promising tool for that purpose. So far 7 out of the 8 patients treated have been satisfied with the result and they would have it repeated in case of recurrence. They are aware that recurrence may occur but they should not show fear of the possibility of another revision since the hospital stays are short, discomfort is tolerable and rehabilitation is quick.
Debridement of an infected total joint arthroplasty with retention of mechanically stable components is often performed for acute cases of periprosthetic infection (PPI). However, the reported success of such a procedure to fully eradicate infection has varied widely. The objective of this study was to elucidate the efficacy of debridement in both infected THA and TKA and attempt to identify risk factors responsible for failure.
During the years 2000–2005, 71 TKA and 69 THA underwent irrigation and debridement for acute PPI (< 4 weeks). All patients were followed up prospectively for at least two years. Detailed data including demographics, comorbidities, surgical history, and medication intake was collected. Intraoperative data, organism profile, and complications were also documented. Failure was defined as patient requiring additional surgical procedure for control of infection or loosening.
Of the 140 patients, 24% required repeat irrigation and debridement for postoperative drainage, hema-toma formation, or systemic symptoms. One third of these revision debridement patients underwent multiple consecutive debridements. Two-stage resection arthroplasty was required in 65 patients (46%) of the entire cohort. Fifty-eight percent of the patients with resection required revision of their cement spacer block due to continuous drainage and systemic symptoms indicative of persistent infection. We noted a total of 86 failures (61%) that required either an additional debridement or resection arthroplasty after the first debridement procedure. The failure rates of THA (62%) and TKA (55%) individually were similar (p=0.253).
Although the concept of conservative management of PPI with debridement and retention of components is an attractive alternative to resection arthroplasty, we have found that 60% of patients undergoing this procedure will inevitably undergo two-stage arthroplasty. Furthermore, more than half of the patients that required resection arthroplasty developed infection of their spacer that entailed revision of the cement block. Therefore, we can conclude that this procedure has a high failure rate and should be implemented in only a select group of patients.
Infection of total hip replacement still is considered a devastating complication. One-stage revision, meaning complete removal of the implant and thorough debridement of the site together with the insertion of a new prosthesis during the same operation, is desirable because of improved rehabilitation of the patient and reduced costs. Although this method is known since more than 30 years it is not used widely yet because of several related risks: known methods rely on the use of antibiotic-loaded cement, which often has shown insufficient release of the added antibiotic. The carrier may even act as a bed for colonisation with selected bacteria. Osseous conditions presented during revisions prevent interconnection of the cement with the sclerotic bone. The toxic monomers of PMMA and heating during polymerisation causes necroses which may be origin of repeated loosening and new growth of bacteria. Filling the defects with cement provides unfavourable conditions in case of another revision, which has to be expected at a high percentage. To overcome these disadvantages uncemented techniques seem to be favourable.
After removal of the implants debridement is performed as in conventional septic surgery. After thorough cleaning and rinsing, bone voids are filled with bone graft using an impaction technique. We use allograft or xenograft bone that is free from antigenic material but intact structures of bone concerning collagen and mineral content. The bone is impregnated with high loads of antibiotic, using a specific incubation technique. There are two options of antibiotic impregnation: vancomycin (“V”) or tobramycin (“T”), the choice being dependent on the causative pathogen isolated. Combinations are possible in cases of mixed infections. The impregnation procedure guarantees high levels of antibiotics at the grafting site for several weeks during which the antibiotic is released into the surroundings. Systemic drug levels are usually undetectable. At the acetabular site we take care that the ground be sufficiently filled with antibiotic graft. Preferably an uncemented cup of hemispherical design is inserted. At the femoral site we prefer implants with a rectangular diameter. This design enables stable press fit contact with the shaft medially and laterally and leaves enough space for graft impaction at the posterior and anterior aspect of the endoprosthesis. Wounds are drained and closed immediately; rehabilitation is performed as after non-septic surgery.
Between 1998 and 2004 thirty-seven patients have been revised because of culture-proven infection of hip endoprosthesis. Causative pathogens were Coag.neg. staph (18x), S.aureus (11x), MRSA (4x), enterococci (9x) and other gram-positive pathogens (3x). In 6 hips gram-negative germs were found additionally. All hips could be followed up with a minimum of 2 years and a maximum of 8 years (mean: 4.1 years).
Wound healing was uneventful in all cases. Mean hospital stay was 16 days (10–32 days). Rehabilitation was in the range of uncomplicated primary THR in cases with short history of infection (up to 3 months) and prolonged in relation to duration of infection and amount of preceding surgery. In three hips there was recurrence of the infection, diagnosed between 6 and 12 weeks after surgery. In one of them the well-fixed stem had not been exchanged, in another one a technical error had occurred during impregnation of the bone graft. This one could be successfully re-operated using the same technique with appropriately impregnated bone graft, the other two were converted to a girdlestone situation. All other 32 hips showed no sign of infection until the last follow-up.
Bone processed in an adequate way represents an excellent carrier for vancomycin and tobramycin. With antibiotic graft compound eradication of pathogens, grafting of bony defects and re-insertion of an uncemented prosthesis may be accomplished in a single operation, making it an ideal tool in one stage non-cemented revision for infected total hip replacement. However, principles of septic surgery need to be observed. We now recommend removing even well-fixed prostheses and taking care, that we implant at least 50cc of well impregnated bone graft. Since the graft gradually is replaced by healthy own bone, improved conditions may be expected even in the case of another revision.
Periprosthetic infection (PPI) is one of the most devastating complications of total knee arthroplasty (TKA). It is widely accepted that resection arthroplasty supplemented with intravenous antibiotics and delayed exchange arthroplasty is the treatment modality of choice for infected TKA. However, the outcome after reimplantation has varied and unpredictable results have been reported. This study evaluates the outcome of this treatment strategy in a single high volume specialised center. Furthermore, our study aims to identify the factors that lead to failure of this treatment.
A thorough review of our joint registry database revealed that 80 patients with an infected TKA underwent resection arthroplasty at our institution during 2000–2005. Sixty-five patients underwent two-stage exchange arthroplasty while the remaining 15 failed to have the second stage reimplantation due to ill health or underwent arthrodesis or amputation. The latter 15 were excluded from the analysis. All patients were followed up prospectively for at least two years. Detailed data including demographics, comorbidities, surgical history, and medication intake was collected. Intraoperative data, organism profile, and complications were also documented. Failure was defined as patient requiring additional surgical procedure for control of infection or loosening.
Two-stage exchange arthroplasty successfully eradicated infection in 45 patients (31%) without need for further treatment. Twelve patients (18%) had recurrent infection that necessitated another resection arthroplasty. Eleven (17%) patients required irrigation and debridement for postoperative purulent drainage which successfully treated infection in 5 cases (46%). The remaining 6 patients failed and required resection arthroplasty. Three additional patients had early loosening of components and required revision arthroplasty. The exact cause of loosening in these patients could not be determined, and despite lack of isolation of organisms infection was suspected. Our analysis identified that irrigation and debridement prior to resection arthroplasty are major risk factors for failure.
Current strategies to treat periprosthetic infection remain imperfect. Two-stage exchange arthroplasty with all its inherent problems and inconveniences imparted a modest success in treatment of PPI at our high volume specialised center. The rise in the number of resistant and virulent organisms, increase in the number of patients with severe medical comorbidities who develop infection may account for the decline in the success of two-stage resection arthroplasty. Novel strategies for treatment of PPI are desperately needed.
One of the routinely used intraoperative tests for diagnosis of periprosthetic infection (PPI) is Gram stain that is reported to carry a very high specificity and a poor sensitivity. However, it is not known if the result of this test can vary according to the type of joint affected or the number of specimen samples collected. This study intended to examine the role of this diagnostic test in a large cohort of patients from single institution.
A review of our joint registry database revealed that 453 total knee arthroplasty (TKA) and 551 total hip arthroplasty (THA) of which 171 and 150 cases were respectively infected underwent revision surgery during 2000–2005 and had intraoperative cultures available for interpretation. A positive gram stain was defined as the visualisation of bacterial cells or ‘many leukocytes’ (> 5 per high power field) under the smear. The sensitivity, specificity, and predictive values of each individual diagnostic arm of Gram stain were determined. Combinations were performed in series that require both tests to be positive to confirm infection and in parallel that necessitate both tests to be negative to rule out infection. This analysis was performed for THA and TKA separately and later compared for each joint type.
The presence of organism cells and ‘many’ neutrophils on a Gram smear had high specificity (98%–100%) and positive predictive value (89%–100%) in both THA and TKA. The sensitivities (30%–50%) and negative predictive values (70%–79%) of the two tests were low as expected among both joint types. When the two tests were combined in series the specificity and positive predictive value were absolute (100%). The sensitivity (43%–64%) and the negative predictive value (82%) improved among both THA and TKA.
The presence of organisms or ‘many’ leukocytes on the Gram smear can confirm PPI in TJA. As expected, the sensitivity and negative predictive value of the two tests were low, and therefore infection could not be safely ruled out. Although the two diagnostic arms of Gram stain can be combined to achieve improved negative predictive value (82%), Gram stain continues to have poor value in ruling out PPI. With the advances in the field of molecular biology, novel diagnostic modalities need to be designed that can replace these traditional and poor tests.
The incidence of periprosthetic knee infection is generally low (0.5%–2%) but the economic impact is great. The rates are higher for rheumatoid arthritis and revision knee surgery. Treatment of periprosthetic knee infection takes into account the acuteness of the infection, the overall immune/medical status of the patient, and the local factors at the site of infection.
Evaluate the results of two-phase exchange arthroplasty with the use of articulating spacer in III-A-1 and III-B-1 periprosthetic knee infection.
From 1990–2005, 24 patients with minimum (< 2) systemic and no local compromising factors were treated for chronic periprosthetic knee infection. These patients staged as III-A-1 or III-B-1 according to MSIS staging system. Diagnosis was clinical, radiological, laboratory and from knee aspiration cultures. Two-phase exchange arthroplasty was performed. Initially, there was removal of the prosthesis, surgical debridement and placement of a PMMA spacer impregnated with antibiotic. The spacer was shaped as a knee joint permitting motion. In 6 cases a hybrid spacer was used (PMMA and TECRES® spacer). Intravenous antibiotic therapy according to intraoperative cultures followed for 6–8 weeks. Re-implantation was always done after the completion of the antibiotic therapy and on the ground of normal CRP, ESR and negative aspiration cultures. All patients received antibiotics after the re-implantation.
Staphylococcus aureus was the most common pathogen followed by Staphylococcus epidermidis and Pseudomonas aeruginosa. No infection recurrence was noted over a 2–15 years follow-up. All patients returned to normal everyday activity. A custom-made prosthesis was placed in one patient and there was a rupture of the extensor mechanism in another.
Patients with periprosthetic knee infection, staged as III-A-1 and III-B-1, when treated with two-stage exchange arthroplasty combined with antibiotic impregnated articulating spacer and i.v. antibiotics can have excellent results.
Two-staged revision TKA is a common strategy for the management of infected TKA (i-TKA) in properly selected patients. However, there is considerable variation in the parameters (e.g. the duration of intravenous administration of antibiotics and of the time interval between the stages, the intraoperative use of frozen sections, the use of knee aspiration etc.) of the treatment protocol among Orthopaedic Centres making the comparative evaluation of results difficult. The aim of this study is to present a standardised two-staged revision protocol with satisfactory mid-term clinical outcome.
Thirty-four consecutive cases of infected primary TKAs were treated in our department between 2000 and 2006. For 24 of them the postoperative follow-up is greater than 2 years. All patients underwent the same treatment protocol: knee aspiration prior to implant removal and surgical debridement, more than 5 specimens for frozen sections and cultures (aerobic, anaerobic and fungi) during the first stage, custom antibiodic impregnated cement spacers, intravenous administration of antibiotics for 3 weeks followed by 3 weeks of per os administration based on culture and antibiogram, a 6-week interval free from antibiotics, second aspiration and second stage with repetition of frozen sections and cultures. In the case of positive frozen section specimens during the second stage the implantation of a new prosthesis was cancelled and a different management strategy was introduced. Preoperative and postoperative data were collected in the form of Total Knee Society Score (knee score and functional score), Oxford-12 Score, laboratory parameters and radiographs at regular intervals.
At the final follow-up 22 out of 24 patients were free of infection. In four patients (2 Host C and 1 Host B) the 2nd stage was repeated (2–6 times) due to polymicrobial infection and positive intraoperative frozen sections. In one of them a knee arthrodesis was finally performed. The diagnostic accuracy of knee aspiration before the 1st stage was low. Total Knee Society Score rose from a preoperative average of 64 (50 to 95) to a postoperative average of 145 (130 to 180). The Oxford 12 score also rose from a preoperative average of 52 (44 to 58) to a postoperative average of 30 (23 to 38). At the final follow-up no radiological signs of implant loosening were observed.
The above standardised protocol of two-staged revision in i-TKA, when indicated, can provide satisfactory mid-term clinical results.
Infection of total knee replacement (TKR) is considered a devastating complication, which necessitates complete removal and thorough debridement of the site. Usually long term antibiotic treatment and a multitude of surgical interventions within a period of several months are required until a definitive supply can be achieved. Osseous defects are common in such conditions and need to be addressed during re-implantation. Managing removal, debridement, reconstruction and re-implantation within a single operation is the ideal solution, both for the patient and the treating team, but rarely executed due to the fear of re-infection. Allograft bone may be impregnated with high loads of antibiotics using a special incubation technique. The resulting antibiotic bone compound (ABC) provides high and long lasting antibiotic levels at the site of infection and is likely to restore bone stock. We have investigated the results of one-stage exchange of infected TKR using ABC together with uncemented implants.
Between 1998 and 2004 nineteen exchange procedures of infected TKRs were performed in a single stage, all of them without the use of bone cement. After removal of the implants and radical debridement bone voids were filled with ABC using a modified impaction technique. Consequently, new uncemented implants were inserted. We mainly used the revision type of the LCS knee (DePuy, J& J) as long as ligamentary stability was considered sufficient. Otherwise, we used a custom-made uncemented version of the LINK Rotational Endo Model. Joints were drained and closed immediately; rehabilitation did not differ from uninfected revision.
One knee required re-revision because of persisting infection. The remaining 18 patients stayed infect-free for a period between 2 and 8 years after surgery. In two knees loosening was found after one year, once of the tibial and once of the femoral component. Both were found infect-free at the time of re-revision. All could be successfully revised using the same technique again. No adverse side effects could be found. Incorporation appeared as after grafting with unimpregnated bone grafts.
Using antibiotic-impregnated allografts eradication of pathogens, grafting of defects and re-insertion of an uncemented prosthesis may be accomplished in a one-stage procedure. Since the graft gradually is replaced by healthy own bone, improved long-term results may be expected as well as improved conditions in the case of another revision.
Several orthopaedic operations are encumbered with a high risk of infection. Early detection of such complication is of utmost importance for achieving good results.
From 1990 to 1998 a prospective study was done in 104 orthopaedic patients, who had a higher risk for postoperative infections. Diagnoses had been chronic osteomyelitis (47 cases), bone transplantation after osteomyelitis (19 cases), malignant bone tumors receiving chemotherapy (16 cases) and revision alloarthroplasty (22 cases). Consecutive levels of leucocytes in the wound drainages (deep and subcutaneus), white blood cell count (WBC) and c-reactive proteine (CRP) were analyzed.
Seventeen patients (septic group) were reoperated for suspected infection. The culture discount revealed Staphylococcus aureus (7 cases), Staphylococcus epidermidis (5 cases), Streptococcus hemoliticus (1 case), Mycobacterium tuberculosis (1 case), Enterococcus fae-calis (1 case), mixed organisms (2 cases), and histological signs of infection (4 cases). Comparing the aseptic and septic group no difference was noted for WBC < 2 days (p = 0.39), 2–3 days (p = 0.18), 3–6 days (p = 0.44) and > 6 days (p = 0.46). CRP difference was noted on the fourth day: mean 7.6 +− 0.8 mg/dl (range 6.0 to 9) (septic group); mean 5.9 +− 1.2 mg/dl (range 3.2 to 8.4) (aseptic group) (p < 0.001). The deep drainage leucocytes demonstrated to 12 hours: mean 5636 +− 2134 (range 2400 to 11200) (septic group) and mean 8531 +− 3312 (range 3100 to 18200) (aseptic group) (p < 0.001). 36 to 48 hours: the values changed adversely. 48 to 72 hours: mean 9146 +− 3666 (range 4700 to 16200) (septic group) and mean 2393 +− 879 (range 1100 to 4100) (aseptic group) (p < 0.001). The subcutaneus drainage leucoytes were 1.5 to 1.9 times higher (aseptic group) and 0.13 to 1.03 times lower (septic group) compared to the deep drainage.
We recommend deep drainage leucocytes monitoring 48 to 72 hours after the operation. Values greater 4100 (upper range of aseptic control) are suspicious and over 9146 (mean value of septic group) are strongly associated with an underlying wound infection.
For local antibiotic therapy gentamycin is in clinical use since many years, originally in the form of PMMA beads, later also in the form of resorbable collagen fleece. A prospective study comparing the efficacy of both application forms so far is missing.
In a prospective study 108 patients with chronic sclerosing osteomyelitis were treated by a standardised operative debridement protocol. The debrided cavities were filled with 54 patients (group 1) were treated by local antibiotic beads (Septopal) and 54 patients (group 2) by local resorbable antibiotic fleece (Sulmycin). Both groups were comparable concerning age, location, duration of operation, type of osteomyelitis and predisposing factors. The mean follow-up was 6.1 years (range 3.8 – 9.3). Evaluation was done for the re-operation rate, CRP and ESR, white blood cells and local wound healing criteria.
Twenty-six patients (44 per cent) underwent one or more revision operations because of persistent infection.
In group I 67 per cent and in group II 20 per cent (p = 0.0001). No difference was noted for CRP (p = 0.46), ESR (p = 0.09), white blood cells (p = 0.24) and local wound healing criteria (p =0.34).
After local gentamycin fleece application the early re-operation rate is significantly lower compared to gentamycin beads. After a treatment period of 3 month this difference disappears.
Copal bone cement loaded with gentamicin and clindamicin was developed recently as a response to the emerging occurrence of gentamicin-resistant strains in periprothetic infections. The objective of this study was to compare the in vitro antibiotic release and antimicrobial efficacy of gentamicin/clindamicin-loaded Copal bone cement and gentamicin-loaded Palacos R-G bone cement, as well as biofilm formation on these cements.
In order to determine antibiotic release, cement blocks were placed in phosphate buffer and aliquots were taken at designated times for measurement of antibiotic release. In addition, the bone cement discs were pressed on agar to study the effects of antibiotic release on bacterial growth. Biofilm formation on the different bone cements was also investigated after 1 and 7 days using plate counting and confocal laser scanning microscopy (CLSM). Experiments were done with a gentamicin-sensitive S. aureus and a gentamicin-resistant CNS.
Antibiotic release after 672 h from Copal bone cement was more extensive (65% of the clindamycin and 41% of the gentamicin incorporated) than from Palacos R-G (4% of the gentamicin incorporated). The higher antibiotic release from Copal resulted in a stronger and more prolonged inhibition of bacterial growth on agar. Plate counting and CLSM of biofilms grown on the bone cements showed that antibiotic release reduced bacterial viability, most notably close to the cement surface. Moreover, the gentamicin-sensitive S. aureus formed gentamicin-resistant small colony variants on Palacos R-G, and therefore, Copal was much more effective in decreasing biofilm formation than Palacos R-G.
Biofilm formation on bone cement could be more effectively reduced by incorporation of a second antibiotic, next to gentamicin. Antibiotic release from the cements had a stronger effect on bacteria close to the cement than on bacteria at the outer surface of the bio-film. Clinically, bone cement with two antibiotics may be more effective than cement loaded with only gentamicin. The clinical efficacy of antibiotic loaded bone cements in combination with systemic antibiotics can be explained because antibiotics released from cements kill predominantly the bacteria in the bottom of the biofilm, whereas systemic antibiotics can only deal with bacteria at the outer surface of the biofilm.
The purpose of our study is to report the incidence of osteomyelitis during the last 10 years in our department. Diagnosis, management and follow-up are also discussed.
We carried out a retrospective study on 40 children who were hospitalised in our clinic between the years 1995–2006 suffering from osteomyelitis. There were 29 male and 11 female children with a mean age 6.8 years. A full blood count, CRP, ESR were measured and X-rays and ultrasound were performed in all patients. Blood cultures were also taken. Additionally, bone scan and CT scan were also performed in 6 and 3 children respectively. The lesion involved in 7 cases the tibia, 9 cases the lower end of the femur and the knee joint, 4 cases the head of the femur and the hip, 7 cases the patella, 4 cases the neck of the humerus, 3 cases the lower end of the fibula, 3 cases the 5th finger of the hand, 2 cases the 4th and 5th metatarsal bones and in 1 case the clavicle. All patients were initially commenced to double antibiotic scheme iv. The microorganisms isolated were Staphylococcus Aureus (27 children-67.5%), Pseudomonas Aeruginosa (9 children-22.5%), Streptococcus Pneumoniae (4 children-10%)
The majority of children (80%) were managed conservatively with intravenous and then oral antibiotic therapy. In 8 cases (20%) surgical debridement was performed due to persisting symptoms and/or aggressive radiologic appearance of the lesion. The mean days of hospitalisation were 17.4 days/patient. A 1.2 year mean follow-up was achieved in all the above patients. All children gradually improved and became pain free, while complete bone resolution appeared in the X-Rays.
Staphylococcus aureus remains the most common organism causing acute osteomyelitis. If left untreated the condition can lead to serious sequelae. The optimal approach in uncomplicated cases may be a combination of aspiration for diagnostic purposes and prolonged antibiotic therapy. A patient’s lack of response to antibiotic treatment and evidence of aggressive radiologic features are indications for surgery.
Severe periprothetic joint infections require a very long treatment. Gram positive microorganisms are an important source of infection in this area. Methicillin–resistant Staphylococcus produces a great number of cases. In this situation a long and effective therapy is required, and Linezolid appears to be an oral alternative. We are concerned about the adverse reactions in 28-day or longer therapy, as gastrointestinal, neuropathics, thrombocytopenia, anaemia and pancytopenia.
The purpose of the study was to observe the efficacy and adverse reactions in periprothetic joint infections that were treated with Linezolid intravenously and orally in our area.
We recorded the clinical and laboratory data of the patients with severe periprothetic joint infections from January to December 2006 at Hospital Clinico San Carlos, Madrid. The inclusion criteria for treatment with Linezolid were: methicillin– resistant Staphylococcus isolates in more than three samples, no contraindication of treatment, and long therapy indicated.
Sixteen patients were included, of whom 11 were women and 5 men. The mean age was 77.8 years (44–82). The infections were located in 10 knees and 6 hip protheses. 11 methicillin-resistant Staphylococcus aureus and 5 methicillin-resistant coagulase-negative Staphylococcus were isolated. Linezolid was administered for a mean of 4.35 months (2–9). For the hip periprothetic infection the treatment lasted 2.5 to 9 months (mean: 3.6 months), and for the knee periprothetic infection 4 to 6 months (mean: 5 months). The infection was ruled out at the end of the treatment in all cases. Just in one case, thrombocytopenia occurred as an adverse event, in a patient treated with linezolid for 2.5 months. Thrombocytopenia reverted when treatment was stopped.
In severe periprothetic joint infections by methicillin-resistant Sthaphylococcus sp. Linezolid is a good choice of treatment. It is an effective antibiotic and its posology makes its use easy and reliable. It is necessary to keep on studying its safety in long therapy clinical trials.
The experience that we gathered using uncemented stems for revisions with diaphyseal anchorage gave us satisfactory outcomes both for survival curve
(94% of cases – 15 yrs follow-up) and for clinical results in the aseptic mobilisations.
Thus, we extended this technique in the re-implant of septic prostheses.
We treated 43 cases of septic hip prostheses from 2003 to 2006. The treatment of choice has been the two-stage revision with the implant of temporary spacer, utilising the one-stage treatment just in few cases selected from needle-aspiration positive culture. The technique foresees the utilisation of Wagner uncemented revision stems in 98% of cases and 2% using a first implant prosthesis. Accompaniment antibiotic protocol has been protracted for 3 – 6 months till the negativity of the inflammation index.
Average follow-up of 26 months shows good clinical and radiographical results with percentage of a new revision of the two-stage in 2.32% (1 case).
The uncemented components are confirmed to be the best presidia for the implant stability retrieval in the immediate and long-term either, the two-stage strategy appears sure enough for the re-infections control especially associated with an adequate antibiotic treatment. Therefore, the choice strategy proposed by us favours the uncemented implants in combination with the two-stage.
Recently procalcitonin has become more interesting with its characteristics as a novel marker for infections rather than with its prehormone characteristics.
Effects of fracture and fracture surgery to serum procalcitonin levels and the value of procalcitonin in differentiating inflammatory reaction caused by fracture surgery from postoperative infective complications were investigated.
Twenty-nine patients (13 women, 16 men; mean age 74.7) who underwent surgery for pertrochanteric fractures were evaluated. Procalcitonin, C-reactive protein (CRP), white blood cell count and body temperature were measured before surgery and for five days postoperatively.
Nine patients developed complications; postoperative wound infection occurred in one and one was lost due to sepsis. Mean preoperative CRP level was five times above the normal. It made a peak on the second day, then began to decrease, but still was four times higher than the preoperative level on the fifth day. Preoperatively, mean procalcitonin level was lower than the normal in all patients. It made a peak on the first postoperative day without exceeding the normal range and returned to the preoperative level on the fifth day. In contrast to CRP levels which were above the normal in all patients, procalcitonin levels were higher than the normal only in patients who developed complications. Sensitivity and specificity of procalcitonin to determine systemic complications were 100% and 95.2% on the first day, respectively (cut-off value ≥0.5 ng/ml).
Procalcitonin is much superior to routinely used infection parameters based on the fact that it is not affected by the inflammatory response resulting from the surgery; it provides a faster response to surgical trauma; it declines more rapidly after removal of the factor leading to inflammatory response and it follows a standard postoperative kinetics. It can be considered as an alarm for possible complications when postoperative procalcitonin levels are above normal.
Intramedullary infection is a challenging problem and management usually includes removal of the infected hardware and reaming of the medullary canal.
The purpose of this study is to describe a new technique for canal debridement and evaluate its efficacy in the treatment of posttraumatic osteomyelitis of the tibia and femur.
This retrospective study included 11 patients (10 male and 1 female, mean age: 42 years) with posttraumatic osteomyelitis of the tibia (n=8) or femur (n=3). Surgical treatment consisted of debridement, implant removal, and reaming of the medullary canal with the RIA (Reamer Irrigator Aspirator) device. All procedures were performed by a single surgeon with a standardised technique. Reaming of the canal was performed with one pass of the RIA. Following reaming, the RIA was used for irrigation of the medullary canal with 10 liters of fluid.
At a mean follow-up time of 9 months (6 to 13 months) there was no recurrence of osteomyelitis. Complications included one partial loss of a flap, one refracture of a tibia following an auto versus pedestrian accident, and external fixator pin tract infections in one patient.
The RIA device allows for reaming under simultaneous irrigation and aspiration, which may minimise the residual amount of infected tissue in the medullary canal. The disposable reamer head is always sharp, in contrast to standard reamers, which may reduce the thermal effects of reaming on the adjacent bone. In addition, the RIA allows delivery of fluid throughout the length of the medullary canal, thus facilitating irrigation. The RIA device is useful alternative for debridement of intramedullary infections of the tibia and femur.
In selected patients, knee arthrodesis is a well-recognised salvage procedure after infected total knee arthroplasty (TKA). Several procedures of arthrodesis have been introduced and should be adapted to the individual situation of the patient. In our center we regularly treat elderly patients after multiple revision operations; in 36% defects of the bone, soft tissue or the extensor mechanisms are present. In these cases we prefer arthrodesis to reimplantation. Because of the high rate of non-unions when using an external fixator, we perform arthrodesis by use of an intramedullary rod system.
The objective of this study was to compare the results of different rod systems for knee arthrodesis after TKA infection.
We reviewed the results of 3 rod systems in 34 patients: cementless system (Brehm; n=9), cement rod usually used in tumor patients (Mutars; n=7) and a regular cement rod system (Link; n=18).
In the group of cementless rods we had to explantate 3 rods because of a relapse of the infection. This is most propably due to the technical design of the system: in poor soft tissue situation the tissue is compressed by the voluminary docking part which causes continuous necrosis. This problem can be avoided by an early tissue flap. Of the Mutars rod system we had to explantate 2 systems; one because of an infection, the other one due to telescoping, which can be avoided by use of a longer stem with the option to interlock. In the group of the Links system no revision was necessary.
In our opinion, arthrodesis of the knee using a rod system is a satisfactory salvage procedure following an infected TKA, especially in elderly patients, and can provide reliable, painless extremity and satisfactory quality of life.
To describe the success rate of surgical debridement and primary closure without implant removal in the treatment of postoperative spinal wound infections with instrumentation.
One thousand four hundred fifty two posterior instrumented fusions were performed between 2000 and 2006. A retrospective record review identified 63 cases with acute (< 6 weeks) postoperative infection (4.6%). The preoperative diagnosis included fracture (24), adolescent idiopathic scoliosis (4), stenosis/degenerative spondylolisthesis (24), adult deformity (4), neuromuscular scoliosis (3), tumor (2), cervical myelopathy (2). All patients were treated with irrigation – debridement and closed suction drainage placement. Cultures were obtained, all wounds closed primarily and appropriate intravenous antibiotic treatments were initiated. The treatment protocol dictated the appropriate time to discontinue drains and antibiotics. The follow-up period ranged from 6 to 24 months.
The majority of infections occurred during the early postoperative period (less than 2 weeks). Fifty-six (89%) resolved without recurrence with only one surgical debridement. Seven patients (11%) required a second operation for irrigation and debridement. Two patients (3%) required implant removal.
Aggressive surgical treatment of postoperative spinal infections is essential for successful outcomes. Removal of implants is not necessary in acute infections. Delayed wound closure or second look operation could be avoided since primary closure offers accepted success rate.
The purpose of this study is to present the preliminary results after treatment of shoulder sepsis with prolonged implantation of an antibiotic-loaded cement spacer in a selected group of compromised patients.
The current study included 11 patients (9 males and 2 females) with a mean age of 64 years (range: 36–79 years). All patients were treated with radical debridement, implantation of an antibiotic-impregnated polymethylmethacrylate spacer, and 6 weeks of antibiotic therapy. The subjective complaints, range of motion of the shoulder, functional outcome (mini-DASH score), and radiographic findings were evaluated. Nine patients at a mean follow-up time of 21 months (range: 13–18 months) were free of infection with pain relief and adequate shoulder function for activities of daily living. Radiographic evaluation revealed no loosening or fracture of the spacer and no progressive degenerative changes involving the glenoid.
Prolonged implantation of the spacer may be a useful alternative in selected patients with poor general condition.
Intraoperative histology has a high specificity and sensitivity to identify prosthetic joint infection. However, the usefulness of this technique according to the type of microorganism isolated in the periprosthetic tissue has not previously been studied.
Frozen sections and cultures from periprosthetic tissue of 38 revision arthroplasties performed due to prosthetic joint infection were retrospectively reviewed. Frozen sections were evaluated according to Mirras’ criteria (adapted by Feldman). Culture was considered positive when the same microorganism was isolated in at least 2 samples or the presence of pus around the prosthesis.
Coagulase-negative staphylococci (CNS) was the aetiology in 13 cases, Gram-negative bacilli in 8, S. aureus in 7, Candida sp and Peptococcus sp in 2 and Enterococcus sp, S.pneumoniae and in 1 case each one. No microorganism was isolated in 4 cases. Frozen sections revealed more than 5 neuthrophils per high power field (forty times) in at least five fields in all cases except in 2 out of 13 caused by CNS (15.3%). A revision of the articles that provided information on the aetiology and the histology supports the findings of our study.
In conclusion, frozen section using Feldman’s criteria had a 15.3% of false negative cases when CNS was the aetiology of the prosthetic joint infection.
Drug injection often results in soft tissue infections of the upper extremity. The purpose of this study was to determine the distinct bacteriologic features of soft tissue abscesses in injecting drug abusers in order to provide guidelines for optimal empiric antibiotic therapy.
Admissions to the musculoskeletal infection ward at our institution from 1993 to 2005 were screened to identify patients with a history of injecting illicit drugs and a diagnosis of a soft tissue abscess. Eight hundred fifty-five patients met these criteria and were included in this retrospective study. There were 638 male and 217 female patients with a mean age of 41.5 years (18 to 75 years).
In the 694 patients with positive cultures the most common organism was Staphylococcus aureus, identified in 359 patients (52%). A progressive increase in the prevalence of ORSA was observed; ORSA comprised 5% of Staphylococcus aureus infections in 1999, 50% in 2001, 56% in 2003, and 82% in 2005. Microaerophilic Streptococcus was present in 37% of culture-positive cases and other anaerobes in 10%. Infections were monomicrobial in 366 of 694 patients (53%) and polymicrobial in 328 of 694 patients (47%).
Staphylococcus aureus is the most common pathogen in soft tissue abscesses in injecting drug abusers with an increasing proportion of ORSA. In addition to surgical decompression of abscesses, broad-spectrum empiric antibiotic therapy may be necessary.
There is little published data concerning long-term outcome in pyogenic spinal infection. Previous studies have used either neurological outcome in isolation, or non-validated quality of life measure instruments yielding data that is difficult to interpret.
To assess long-term outcome following pyogenic spinal infection through standardised outcome measures, Oswestry Disability Index (ODI) and Short Form-36 (SF-36) were utilised.
All cases of pyogenic spinal infection presenting to a single institution over the period 1993–2003 were retrospectively identified. Inclusion in each case was based on consistent clinical, imaging and microbiology criteria. The follow-up was by clinical review, American Spinal Injury Association (ASIA) classification, ODI and SF-36. The outcome was compared to normative data for the Irish population.
Twenty-nine cases of pyogenic spinal infection were identified. Nineteen patients (66%) had an adverse outcome at a median follow-up of 61 months, despite only 5 patients (17%) who had persistent neurological deficit according to ASIA classification. A significant difference in SF-36 PF (physical function) scores was observed between patients with adverse outcome and those who recovered (p=0.003). SF-36 scores failed to reach those of a normative population, even after apparent full recovery. A strong correlation was observed between ODI and SF-36 Physical Function scores (rho=0.61, p< 0.05). Seventeen percent (n= 5) of admissions resulted in acute sepsis-related death. Delay in diagnosis of spinal infection (p= 0.025) and neurological impairment at diagnosis (p< 0.001) were associated with neurological deficit at follow-up examination. Previous spinal surgery was a significant predictor of adverse outcome in patients requiring readmission < 1 year (p= 0.018).
The finding of high rates of adverse outcome and using SF-36 and ODI suggests under-reporting of poor outcome in other series. We advocate use of validated standardised spinal outcome questionnaires to accurately assess long-term outcome and facilitate comparison between case series.
Deep infection following total knee arthroplasty (TKA) is a devastating complication for the patient and a costly one for patients, surgeons, hospitals and payers. The aim of this study is to compare revision TKA for infection, revision TKA for aseptic loosening and primary TKA with respect to their impact on hospital and surgeon resource utilisation. The evaluation of hospital cost was carried out on a microeconomic basis in order to best evaluate the true cost.
Demographic, clinical and economic data were obtained for 25 consecutive patients with an infection after TKA who underwent a two-stage revision arthroplasty (Group 1), 25 consecutive patients who underwent revision of both components because of aseptic loosening (Group 2) and 25 consecutive patients who underwent a primary TKA (Group 3), all of which where admitted at our institution between January 2000 and December 2005. The economic evaluation included both surgical treatment and hospitalisation cost. Because fixed charges do not depict accurately real resource consumption, total cost was calculated through direct cost analysis. All direct health sector costs such as medical supplies, drugs, implants, laboratory and radiology tests, salaries and wages and overhead expenses, including equipment and plant depreciation were calculated. All patients were followed up for a twelve-month period.
Revision procedures for infection were associated with longer operative time, more blood loss and a higher total number of operations compared with both revisions for aseptic loosening and primary TKA. Furthermore, revisions for infection compared to revisions due to aseptic loosening and primary TKAs were associated with twofold and 2.6 times higher total number of hospitalisations, 2.5 and 5.6 times higher total number of inpatient days, 10.2 and 53.8 times higher cost of inpatient drugs and 1.2 and 2.37 times higher cost of implants, respectively. The costing evaluation of the three operative techniques is still on progress.
Patients’ treatment with an infection after TKA is associated with significantly greater hospital and physician resource utilisation compared with that used for patients with a revision due to aseptic loosening or a primary TKA.
Some different biodegradable vehicles have been tried in vitro and in vivo as possible methods of local antibiotic therapy.
The aim of this study is to evaluate the effectiveness of collagen-gentamicine (Collatamp®) to eradicate bacterial colonisation of different biomaterials used in orthopaedic surgery in an in vitro study.
Three samples of similar shapes and dimensions of 4 different materials: stainless steel screw, titanium screw, titanium canulated screw and a cylinder of polyethylene were used. Three different solutions of 49 cc of thioglicolate plus 1cc of solution of methicillin-susceptible and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis (MacFarland: 3) were prepared. Each solution received one sample of each material so that every material be tested in all 3 preparations. After incubation during one week and confirmation of bacterial colonisation of each sample by swabbing cultures, all of them were introduced in an individual receptacle containing 50 cc of thioglicolate and a piece of 5x5 cm of collagen-gentamicine (corresponding to 650 mg/ml of gentamicine). After incubation we analysed results by new swabbing cultures of all samples.
All samples were highly contaminated with different bacteria before introducing them in thioglicolate with the piece of collagen-gentamicine. After one week all samples were free of bacteria.
This in vitro study demonstrates the effectiveness of collagen-gentamicine in order to eliminate colonisation of different biomaterials used in orthopaedic surgery by most frequent bacteria.
Radiological evaluation is crucial for interpretation of experimental osteomyelitis studies. Current scoring systems for radiologic evaluation of experimental osteomyelitis have limitations to demonstrate differences among treatment groups. Response of bone tissue to infection is a dynamic process; each radiological sign of osteomyelitis becomes prominent at different time points of disease. Analysing radiological criteria separately at different stages of the disease may provide better quantification of the response to treatment in experimental osteomyelitis rather than summation of these grades together.
Osteomyelitis was induced with S.aureus in left tibias of 72 adult, wistar albino rats. Rats were assigned into six different treatment groups. Their radiograms were graded according to previously defined scoring systems, and each radiological criterion separately, at the third week of induction, and at the third and sixth week after treatment.
Although periosteal reaction and diaphyseal widening demonstrate significant differences with three weeks of treatment, previously defined scoring systems could not find significant differences. At the sixth week of treatment, only one of the previously defined grading scales was able to differentiate significance among the treatment groups. Individual values of diaphyseal widening, osteolysis, BMC values were pointed out differences among the groups in the presence of osteomyelitis, confirmed by osteomyelitis.
Formulation of radiological grading scales requires evaluation of periosteal elevation, diaphyseal widening, bone deformation, osteolysis, and osteosclerosis, individually. However, evaluation of these scores separately will multiply interpretations of future studies, and will make them more meaningful.
In the recent years the number of patients treated for infective spondylodiscitis at our institution increases steadily. In a previous analysis it was demonstrated that Staphylococcus aureus was the most frequent pathogen causing this infection. The aim of the present study was to evaluate whether infection with this pathogen carries also a worse prognosis.
Case records of patients treated for spondylodiscitis at the Department of Infectious Diseases, Ljubljana in the years 1990 – 2006 were reviewed. The following data were recorded: age, sex, clinical features, causative agents, underlying disease, previous or concomitant infections, previous operations, results of x-ray and other diagnostic examinations, complications and outcome of the disease. The data were analysed using EpiInfo 6.
One hundred twenty six patients (78 males, 48 females) with infective spondylodiscitis were analysed in this study. The mean age was 61.6 years (range: 20 – 95 years). In 97 (77%) patients the causative pathogen was demonstrated. S. aureus was the most frequent pathogen isolated in 66 (52.4%) out of all the patients and in 65% of all microbiologically documented infections. Only two isolates were methicillin-resistant. Staphylococcal infection was significantly more frequent in male than in female patients (P = 0.04). There were no significant differences in age, underlying diseases, previous operations and other risk factors between patients with staphylococcal and non-staphylococcal spondylodiscitis, although patients with non-staphylococcal infections were more likely to have a previous infection during the six months before the beginning of their illness. Case-fatality rate was 9.5%, 12 patients died. There was no difference in mortality between the two groups, but patients with staphylococcal infections had significantly more complications such as epidural or paravertebral abscesses (P < 0.002) and were also more frequently operated on (P = 0.02). The duration of treatment and hospitalisation did not differ significantly between those two groups. In 9/128 (7.3%) patients, infective endocarditis was also found.
S. aureus remains an important pathogen causing spondylodiscitis. Mortality in recent years has decreased significantly at our institution but our results show that patients with staphylococcal spondylodiscitis tend to have a more severe course of the disease and are more often in need of surgical intervention.
The differential diagnosis of pain after total knee arthroplasty (TKA) should always include periprosthetic infection (PPI). The current diagnostic tools vary in sensitivity, specificity, and predictive value. Currently, there is no test with an absolute accuracy for diagnosis of PPI. Furthermore, cost effectiveness of investigations has become an important issue in recent years as increased expenses can place an unnecessary heavy burden on the medical system.
We retrospectively evaluated 296 patients who underwent revision TKA at our institution during 2000–2005 and had preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) performed. The criteria used for diagnosing infection were a positive intraoperative culture on solid media, presence of an abscess or sinus tract that communicated with the joint, positive preoperative aspiration culture, and/or elevated fluid cell count and neutrophil differential of the aspirated fluid. The sensitivity, specificity, and predictive values of ESR and CRP were determined. Combinations were performed in parallel that necessitate both tests to be negative to rule out infection. The cost of each serological test was compared to that of other commonly used screening modalities.
One hundred sixteen patients (39%) were classified as infected and 180 patients (61%) were considered non-infected. The sensitivity, specificity, positive predictive value, and negative predictive value for the ESR were: 91%, 72%, 68%, and 93%. The sensitivity, specificity, positive predictive value, and negative predictive value for the CRP were: 94%, 74%, 70%, and 95%. The sensitivity and negative predictive value for the combined studies were 96% and 95% respectively. However, five infected patients (4%) had a normal ESR and CRP. An organism was cultured on solid media in 4 of the 5 cases.
ESR and CRP were the least costly of all the preoperative tests including radionuclide imaging and joint fluid analysis. ESR and CRP are important preoperative tests in the diagnosis of PPI and their ability to clench diagnosis in the majority of cases should not be underestimated. When combined, those simple serological tests have improved sensitivity and negative predictive value to rule out infection.
Bisphosphonates are systemically used for the treatment of metabolic bone diseases such as osteoporosis or aseptic loosening after joint replacement surgeries, and there are limited studies on their effects when applied locally. Furthermore, effects of biphosphonates in osteomyelitis treatment are not well-known. A prospective longitudinal randomised controlled study was designed for the rat tibia to test the efficacy of local or systemically administered bisphosphonates for controlling the localised osteolytic reactions and possible effects on local infection control.
Osteomyelitis was induced in the tibia of 72 Wistar albino rats with S. aureus ATCC 25923 strain. All rats in all treatment groups were given curettage and debridement surgery. Rats in Group I were left without any bone grafting. In Group II, dead space was grafted with plain bone graft, while in Group III rats were treated with vancomycin-loaded bone grafts. In group IV, defects were filled with vancomycin-loaded bone grafts, and this was combined with weekly subcutaneous alendronate application at a dose of 240 μg/kg/wk. At Group V defects were grafted with alendronate impregnated bone graft. Finally, rats in Group VI received vancomycin + alendronate impregnated grafts. Dependent variables were groups (n=6) and time (n=2) whereas independent variables were swab cultures, radiology, quantitative computerised tomography, dual energy X-ray absorptiometry and histopathology.
Within three weeks, S.aureus was isolated in all groups. Within six weeks, S.aureus was eradicated in Groups II and IV according to the results of swab cultures. Radiological diaphyseal widening was significantly lower (p=0.037) in Group VI at three weeks. Bone deformation, diaphyseal widening and osteolysis scores were lower in this group at six weeks. Bone mineral content and density measured by quantitative computerised tomography were significantly higher (p=0.001) in Groups IV and VI at six weeks. Bone mineral density measured by dual energy X-ray absorptiometry was significantly higher in Group IV at six weeks. Histology revealed marked osteoblastic activity in Groups IV and VI at six weeks.
Acute osteomyelitis (OM) and septic arthritis (SA) are two issues of great concern and debate for the pediatric orthopaedic surgeon.
Our purpose is to study the frequency of both diseases in the current years in comparison to the past, as well as other parameters that affect their progress such as time between the onset of the disease and the admission to the hospital, and pathogens that are found in pus and types of therapy.
Three periods were studied: Period A: years 1963–1975, Period B: years 1975–1983, Period C: years 2000–2005. In total, there were 451 patients suffering from OM and SA in Period A, 208 cases in Period B and 95 cases in Period C.
OM is found most often in the femur (A: 34.91%, B: 32.32%, C: 54.54%) and the tibia (A: 43.27%, B: 43.43%, C: 13.63%). SA is found mostly at the knee (A: 17.46%, B: 42.70%, C: 47.76%) and the hip (A: 50%, B: 37.50%, C: 41.79%) joints. A great percentage of patients in Period A (36.80%) are admitted to hospital very late (> 20 days from the onset of the disease); this number falls dramatically in Period C. There is, on the other hand, early admission to hospital (< 3 days) in period C (C: 74.73% versus A: 13.08%). No significant difference among age groups is apparent; 6–11 years of age are the most frequent. Staph. aureus has always been the most usual pathogen found in pus in the majority of cases. A great number of patients in Period A are admitted to hospital being already under antibiotic therapy (60.58%). This percentage falls in Period C (11.57%).
A decrease in the frequency of OM and SA in the recent years is obvious. Most of the patients are admitted early to hospital and due to this event, there is significant improvement concerning the complications from the diseases, in comparison to the past.
It is known that wide variability exists among patients in the susceptibility to and outcome from infection. Polymorphisms in genes coding for proteins involved in the response to bacterial pathogens as tumor necrosis factor-alpha(TNF-a), interleukin (IL)-1alpha, IL-1beta, IL-1 receptor agonist, IL-6, IL-10 can influence the amount or function of the protein produced in response to bacterial stimuli. These genetic polymorphisms may influence the susceptibility to and outcome from infection.
The aim of the study was to investigate whether genetic variation in genes coding for components of the innate immune response might be a critical determinant of the inflammatory response and the risk for and outcome from severe bacterial infection in individuals with musculoskeletal infections. The relationship between single nucleotide polymorphisms (SNPs) in the above mentioned genes and susceptibility to infection was evaluated.
Forty patients with musculoskeletal infections hospitalised at the Orthopaedic Clinic of University Hospital of Larissa, as well as 80 healthy controls were included in the study. Genomic DNA was isolated from peripheral blood from all cases and controls and was extracted according to standard procedures. The following genes with their polymorphic positions were studied: IL 1α (IL 1α promoter −889), IL 1β (IL 1β promoter −511, pos. +3962), IL 1R (IL 1R pos. pst1 1970), IL 1RA (IL 1RA pos. mspa1 11100), IL 4Rα (IL 4Rα pos. +1902), IL 12 (IL 12 promoter −1188), TGF-β (TGF-β exon 1 codon 10, codon 25), TNF-α (TNF-α promoter −308, −238), IL 2 (IL 2 promoter −330, pos. +166), IL 4 (IL 4 promoter −1098, −590, −33), IL 6 (IL 6 promoter −174, pos. +nt 565) and IL 10 (IL 10 promoter −1082, −819, −592). Genotype distribution and allele frequencies in patients and controls were evaluated.
There was a significant difference in genotype and allele frequency of IL-1a (T/C −889) p=0.000 (CC, TC) between patients and the control group. Moreover, 2 SNPs of interleukin 4 [IL-4 (T/G −1098) p=0.000 (GG, GT) p=0.009 (TT) and IL-4 (T/C-590) p=0.000 (CC, CT) p=0.006 (TT)] showed significant genotypic and allelic differences between the two groups. Finally, 2 SNPs of interleukin 6 [IL-6 (G/C-174) p=0.000 (CC) p=0.014 (GG), IL-6 G/A nt565) p=0.000 (AA,GA,GG)] and TNF-a [(G/A-308) p=0.034 (AG)] showed significant differences in genotype and allele frequencies between patients and the control group.
We observed, for the first time, significant differences in genotype and allele frequencies of TNF-a (G/A-308), IL-1a (T/C -889), IL-4 (T/G -1098), IL-4 (T/C-590), IL-6 (G/C-174) and IL-6 G/A (nt565) in patients with musculoskeletal infections, a fact which points towards the involvement of cytokine gene polymorphisms in the pathogenesis of infection.
A 51-year-old Caucasian woman was admitted to the Rheumatology Department of our hospital due to a 3-week history of diffuse neck, shoulder and upper torso pain, exacerbated by movements. An outpatient trial of non-steroidal anti-inflammatory medications had been unsuccessful. A few days later, the pain was localised above the manubrium, the left clavicle and sternomastoid muscle and fever up to 39.5°C was reported. The patient had no significant past medical history and lived in a suburban area. She did not work and liked to do gardening in her spare time. There was no history of local trauma or any medications. On examination, there was intense redness, tenderness and swelling of the manubrium and the left sternoclavicular joint. Chest CT revealed osteolytic changes of the manubrium and presence of inflammatory tissue surrounding the manubrium and extending posteriorly. The lung parenchyma was unaffected. Brain and abdominal CT were unremarkable. A triple-phase bone scan was indicative of sternal osteomyelitis without other bone involvement. Blood and urine cultures remained negative. The patient was empirically treated with high-dose intravenous vancomycin and ciprofloxacin with no response. Antibody testing to human immunodeficiency virus and hepatitis viruses was negative. An open biopsy was performed 1 week later, revealing persistent inflammatory tissue around the sternum and fluid collection posteriorly. Multiple bone specimens were sent for histological examination and cultures. Histology showed acute and chronic granulomatous inflammation, while both cultures of the bone marrow and the fluid revealed Nocardia nova. No other pathogen was identified. The patient responded to high-dose intravenous trimethoprim-sulfamethoxazole, which was continued on an outpatient basis for 1 year without further sequelae.
This is the first reported case of primary sternal osteomyelitis due to Nocardia species. The possibility of nocardiosis needs to be included in the differential diagnosis of sternal osteomyelitis, even for apparently immunocompetent adults.
Femoral head aseptic necrosis is a common complication after HSCT. In allogeneic HSCT recipients, hip tuberculosis on top of aseptic necrosis is infrequent and the mortality is high.
We present a case of hip joint tuberculosis in a 57-year-old man with acute myelomonocytic leukemia (M4) treated with HSCT. The patient developed extensive chronic graft versus host disease (cGVHD) five months after transplantation and was treated with cyclosporine and corticosteroids. Eight months after the transplantation because of low-grade fever, elevated ESR and abnormal chest CT scan findings, empirical anti-TB treatment started despite negative tuberculin skin test. Three weeks later anti-TB treatment was stopped because of hepatic enzyme elevation. One year after the transplantation he complained about bilateral hip pain. MRI revealed bilateral femoral head aseptic necrosis. One year later, the right femoral head collapsed, and suddenly, rapid hip joint destruction occurred. He was planned to have total right hip arthroplasty. During the operation an abscess was evacuated and biopsy showed tuberculosis. Necrotic tissues and bone were removed and suction drainage was applied. Diagnosis was confirmed by acid-fast stain, PCR and cultures. In BACTEC MGIT 960 culture system and on Löwenstein-Jensen Mycobacterium tuberculosis was isolated, which was sensitive to all first line anti-TB drugs. After one year of anti-TB treatment (HRZE for 2 months followed by HRE for 10 months), synovial fluid samples were negative for tuberculosis. The patient was submitted to cementless total left hip replacement. Three months later, the right hip was allografted on the acetabular side and a reinforcement ring was used in order to perform a successful total hybrid arthroplasty. Nine months postoperatively the patient is symptom free and able to walk.
Tuberculosis should be considered in the differential diagnosis when rapid joint destruction occurs. Early diagnosis improves response to anti-TB therapy and surgery.
lytic areas surrounded by a halo of sclerosis in the greater trochanter (in 18 cases they were very small and in 14 cases of a greater size). These areas were statistically significantly related to a greater rate of wear; some degree of diffuse osteopenia was seen in 19 cases.
Eight of the 13 frozen menisci were classified as grade III (61.54%) and 5 as grade II. In the control group 6 were classified as grade I (46.15%) and 7 as grade II (53.85%). Frozen menisci averaged 4.85 points and the control menisci 2.46 (p< 0.001).
(1) Women undergoing elective hip arthroplasty frequently have abnormal preoperative urine analysis. (2) Asymptomatic urinary infection is only detected in a small percentage of patients that undergo programmed hip arthroplasty. (3) No hip prosthesis infection has been seen during follow-up up to the current time.
To describe the health status of patients after total knee replacement (TKR) and compare it with the state of health of a comparative Spanish population To compare generic and specific measurements of health related quality of life (HRQofL) in patients 18 months after TKR.
Study of the evolution at 36 months of health-related quality of life (HRQofL) in patients with significant knee arthritis that undergo TKR and Identification of social, demographic and clinical variables that affect HRQofL.
Female sex and a greater frequency of hallux rigidus have a statistically significant relationship (p=0.095) for a 90% confidence interval. This is contrary to the opinion expressed in most of the literature published up to the present. The height of the patient and a greater frequency of hallux rigidus seem to have a statistically significant relationship for a 90% confidence interval (p=0.067). This has not been mentioned up to now in any published paper. The For factors such as hypermobility of the 1st toe, excess of the 1st axis, adductor metatarsus, interphalangeal hallux valgus and chevron shaped joint, we have found no significant relationship with the development of hallux rigidus.
One of these total hip arthroplasties has been revised for incomplete femoral fixation leading to a 96% survival rate at an average follow-up of 22 months (range: 2 – 74 months). The average Harris Hip Score for these patients at the most recent follow-up was 87.
All reviewed studies were divided into cemented, cementless, or hybrid fixation, as well as year of implantation (before and after 1990). In addition, patients were stratified according to comorbidities, age, gender, and various diagnostic and other risk factors (e.g. systemic lupus erythematosus, sickle cell disease, use of corticosteroids, alcohol abuse).
There is a paradox surrounding the use of bisphosphonates and bone biology. On one hand, it has been used to treat osteoporosis, osteogenesis imperfecta, Pagets disease, osteonecrosis, and other disorders associated with low bone mass. On the other hand, there have been a number of cases reported suggesting an association between treatment with bisphosphonates and osteonecrosis of the jaw. Answers to why this paradox exists lies in a better understanding of the pathogenesis of osteonecrosis and the mechanism of action of bisphosphonates. This seminar was created to explore the perspectives of three different medical disciplines concerning the use of bisphosphonates.
Osteonecrosis of the femoral head is a debilitating disease caused by disruption of the blood supply to the femoral head that typically affects the younger population. Associated risk factors or etiologies include alcoholism, use of corticosteroids, trauma, blood disorders, radiation therapy, and dysbarism. In the United States, it is estimated that 10,000 to 20,000 cases occur annually and that 5% to 12% of total hip arthroplasties are performed to treat the disease. Surgical intervention is likely to be more effective when performed in the early stages of osteonecrosis, prior to collapse of the femoral head and subchondral plate.
Porous tantalum (trabecular metal) implants have been used in patients with early stage osteonecrosis of the femoral head for several years. Initial clinical results show several benefits including reduced surgical time, blood loss and hospitalization compared to patients treated with vascularized fibular grafting.
Clinical experience has shown that, like other joint preserving treatments for osteonecrosis, it is possible to identify patients with specific selection criteria that will yield the best outcomes for treatment with the porous tantalum implants. With this in mind, this implant can be included in the treatment armamentarium for early stage osteonecrosis.
Core decompression is a common treatment for early stage osteonecrosis of the femoral head due to the simplicity of the procedure and the positive results of this intervention. A number of different core decompression methods exist: including methods backfilled by a bone graft material and those without filling. Due to the inherent desire that the core decompression defect regenerate healthy bone, reduce pain, and stave off the need for total hip arthroplasty for some period of time, this surgically created defect is an excellent application for the use of a bone graft substitute.
Recently, an injectable calcium sulfate (CaSO4)/calcium phosphate (CaPO4) composite graft has become available for use in the treatment of surgically created defects. The synthetic graft is an injectable composite of CaSO4, tricalcium phosphate (TCP) granules, and brushite that hardens
Early clinical series have indicated similar results to the canine studies. Reports of early clinical findings have included a 12 patient benign bone tumor series with 4–12 month follow up and a core decompression series of 38 Ficat stage I–III hips with 6–16 month follow up. Preliminary radiological results in the bone tumor series showed peripheral resorption of the injectable CaSO4/CaPO4 composite with new bone formation along the resorbing edge. Clinically, patients in the bone cyst series have not experienced fractures or additional surgery and all patients have displayed full functional recovery. In the core decompression series, 32 of the 38 hips experienced pain relief and within the subset of 30 symptomatic hips, 24 had pain relief. These results, although preliminary, are promising outcomes.
Collectively, the pre-clinical and preliminary clinical results indicate that the use of an injectable CaSO4/CaPO4 composite could prove to be of benefit in core decompression of the femoral head. The staged resorption and dense bone formation evidenced in canine studies would be desirable in core decompression techniques where healthy bony ingrowth is the goal. Due to the straightforward compilation and use of this composite, the incorporation of this material as a backfill matrix into the core decompression procedure is technically simple. Although additional studies are certainly merited, these early clinical results are encouraging.
The cultures demonstrated viable hMSCs that were identical to a commercially available cell line. The cultures were transferred into osteogenic media; after 10 days the bone marrow derived cells and the commercial cell lines were stained with Von Kossa silver stain and for alkaline phosphatase demonstrating osteoblastic differentiation.
Hind limb ischemia studies have demonstrated that laser doppler blood flow was significantly better following BMAC infusion as compared to cells concentrated with Ficoll. These results were confirmed by a Boyden chamber migratory assay.
Measurement of blood flow to the skeleton is technically challenging. The specific problems of measuring blood flow that are particular to bone are:
i) there are 206 separate bones in the skeleton; ii) each bone has multiple arterial inputs and venous outflows; iii) each bone is heterogeneous, comprising varying proportions of cortical bone, cancellous bone, and marrow (both haematopoietic and fatty).
Because of this heterogeneity of the tissue, it is also important to specify precisely the region of bone that is being measured, and this problem accounts for some of the discrepancies in values of bone blood flow quoted in the literature. From a practical orthopaedic perspective, techniques to measure regional blood flow are normally more informative than measurements of total skeletal blood flow.
In experimental studies, the microsphere technique has been used most widely for the quantitative measurement of bone blood flow, and is regarded as the gold standard. Particles of the order of 15 microns in diameter are injected into the ventricle and trapped in the microcirculation during a single passage. The distribution of microspheres in the body is proportional to the distribution of cardiac output, and if a reference arterial blood sample is taken during injection of the microspheres, then blood flow may be calculated. Microspheres are normally labeled with a radioactive tracer or a colored dye, and microsphere number is estimated from assays of the attached label.
The microsphere technique is a specific example of indicator fractionation, and clinically indicator fractionation can be applied using imaging techniques such as magnetic resonance imaging (MRI) or positron emission tomography (PET). MRI-based techniques are based on gadolinium contrast agents, and PET uses positron-emitting isotopes such as oxygen-15 labelled water, fluorine-18 ion, or 18F-fluorodeoxyglucose. Positron-emitting isotopes are short-lived, and need to be produced daily by a cyclotron, limiting the general utility of the technique. However, dynamic PET measurements with fluorine-18 have been used to assess simultaneously both bone blood flow and bone formation rates.
Blood flow can also be estimated from velocity measurements, e.g. electromagnetic flowmetry, laser Doppler, and ultrasound Doppler. Laser Doppler measurements require contact between the probe and the tissue being measured, and have applications in experimental studies of vascular reactivity in bone. Although ultrasound is reflected very effectively from bone surfaces, ultrasound Doppler has been used to image the lumber arteries in patients with degenerative disc disease.
Bone, like other tissues in the body, is relatively transparent to light in the near-infra red, but there are specific absorption peaks for deoxy- and oxy-hemoglobin. This is the basis of near infra-red spectroscopy for perfusion measurements. However, because of the complexities of light scattering in tissue, spatial resolution is poor. Measurements in the proximal tibia are quite straightforward, and we are currently using this technique in studies of bone loss in spinal cord injury patients.
Diabetes was the strongest independently predictive factor for ON-free survival (relative risk 0.47, p< 0.0001), while other factors were also independently significant but had a weaker relationship; (rejection episodes [RR 1.17, p=0.009], year of transplantation [RR 0.96, p=0.01]).
Presence of diabetes is associated with a dramatic risk reduction in developing ON. The magnitude of the risk reduction was greatest for diabetes as compared to all other risk factors analyzed.
The Johns Hopkins University Department of Orthopaedics at the Good Samaritan Hospital, Baltimore, Maryland USA
Imaging techniques continue to gain in sophistication. Gd-enhanced MRI can be used to assess perfusion of the diseased tissue. Doppler ultrasonography has also been used to estimate blood flow noninvasively. Near Infrared Spectroscopy (NIRS) can be used to measure tissue oxygenation.
While there has been recent interest in using biomarkers or genetic markers in the diagnosis and analysis of disease progression, more research is needed to determine the sensitivity and specificity of these techniques with respect to osteonecrosis.
The concept that fluid percolating through bone matrix is the basis for mechanotransduction of stress stimuli to modeling and remodeling has proved challenging
In order to make this explanation more intuitive we have developed a metaphorical rendering of the model. The rendering adds an extension to include our current model for the effects of skeletal muscle contraction on the basic multicellular unit (BMU). In the metaphor, cortical bone is the continent nation HaroldFrostland. Its cities are fed by waterways which serve as metaphors for each of the fluid transporting pathways from arteries to inter-collagen spaces of bone matrix.
Bounding the continent are oceans wherein underwater earthquakes—metaphors for skeletal muscle contractions—generate solitary pressure waves (tsunamis) and a ripple effect in continental waterways. Critical for penetration by and effectiveness of such solutions is that flow resistance in the waterways must allow pressure buildup. Locks/valves serve to provide this resistance. When pressure is sufficient filtration at transfer points—metaphors for where nutrient exchange occurs--is enhanced. By this means, muscle contraction enhances delivery of fluid not only to bone cells; but around them as well, stimulating mechanotransduction.
Recent analysis of the Australian Joint Replacement Registry revealed the rate of revision of primary total hip arthroplasty was greater with cement-less fixation than with cemented fixation. The seven-year results of the New Zealand Joint Registry have also shown an increased revision rate with cement-less hip arthroplasty. The purpose of this study was to review the revision rate of cemented and cement-less total hip arthroplasty from those joint replacements registered with the New Zealand Joint Registry and to determine the cause for revision.
All 42 1000 primary total hip arthroplasties recorded in the New Zealand National Joint Registry since its establishment in 1999, until December 2006, were included in the study. The rate of revision of cemented and cement-less femoral and acetabular components was calculated for the study period, and for the first 90 days after the operation. The reasons for revision were evaluated and compared for different methods of fixation. Survival curves were constructed for each combination of femoral and acetabular component fixation.
Two hundred and eighty three cement-less (2.46%), 294 cemented (1.91%), and 321 cemented femoral with cement-less acetabular fixation (2.19%) primary total hip arthroplasties have been revised. The difference in revision rate between each group was statistically significant. There were only 573 primary total hip arthroplasties performed with cement-less femoral and cemented acetabular component, with 11 revised. The rate of revision was highest in the cement-less group (0.74% revised per year), and lowest in the cemented group (0.47%).
The predominant reason for revision in all three major groups was dislocation. Revision for loosening of the acetabulum was more common with cemented fixation. Revision for fractured femur was more common with cement-less fixation, and revision for deep infection was most common in the cemented group. These differences were all shown to be statistically significant. Revision for loosening of the femoral component and pain was more common in the cement-less group, but was not shown to be statistically significant.
In the first 90 days, there were a large number of revisions in the cement-less group (0.77%), compared to the cemented group (0.32%), and cemented femur with cement-less acetabulum group (0.57%). Dislocation was again the most common reason for revision. Revision for fractured femur was high in the cement-less group (0.19%) in the first 90 days. Excluding these early revisions, the number of revisions in the cemented and cement-less groups maintained a similar rate for the remainder of the study period.
This study confirmed that the revision rate for uncemented THA was higher than for cemented THA. The major difference was the early revision rate within 90 days. Addressing these problems would improve the overall early outcome.
The human hip capsule is a heterogeneous structure contributing greatly to the stability of this joint. A posterior approach to the hip necessarily sacrifices the ischio-femoral ligament but the decision to release the ilio-femoral and pubo-femoral ligaments remains at the discretion of the surgeon. This mechanical study aims to demonstrate that these anterior capsular structures, when left intact, may limit the external rotational range of motion when the variables of femoral offset, leg length and neck version are adjusted at the time of surgery.
A dry bone pelvis-femur model was prepared and registered with the Stryker iNstride Hip Navigation software. A cemented 28 HDPE contemporary cup was inserted at 45° inclination with 20° of anteversion and a revision modular stem implanted in the femoral medullary canal. Artificial ilio-femoral and pubo-femoral ligaments were then prepared from plastinated rubber fabric and mounted in their anatomical positions. Using this model, a range of restoration body sizes was sequentially introduced to vary the offset. The rotational range of motion was then assessed. Repeat measurements were made using + 10mm length bodies across the same offset range. Finally, assessments of rotational range of motion were made using the 19mm body alone while varying neck lengths and degrees of version were trialled. All measurements of external rotation were taken in a position of 0° hip flexion and 0° abduction, as determined using the Stryker iNstride Hip Navigation System.
As femoral offset was increased using our model, there was a progressive loss of external rotation. This consistent restriction of external rotation was further accentuated when +10mm length bodies were trialled across the same range of offsets. When a standard 19mm restoration body was placed and a range of heads trialled, it was again found that increasing neck length consistently correlated with a reduction in external rotation. Varying the restoration neck version with a standard head, it was found that increasing retroversion correlated with an increase in the external rotational range of motion.
The findings of this mechanical study suggest a progressive limitation of hip external rotation with increasing femoral offset and leg length when the anterior capsular structures are intact. Such findings are of importance in pre-operative planning as they suggest that increases in these variables may significantly limit a patient’s range of external rotation unless the anterior hip capsule is released. Such considerations must of course be balanced against the potential to destabilise the hip if too extensive a soft tissue release is performed. The artificial model used in this study is intended to approximate the human hip and its ligaments. The absolute values for rotational range of motion measured using the Stryker hip navigation system are less significant than the overall trend which they suggest. A patient-based study is now planned to further test these findings.
We have performed an RCT of cross-linked versus non cross-linked polyethylene with 125 patients followed for five years. The study showed a dramatic reduction of wear with the cross-linked polyethylene consistent with the in-vitro studies. Because it has been recognised that hard bearings are sensitive to edge loading we were concerned that highly cross-linked polyethylene might exhibit wear properties similar to hard bearings. We have therefore analysed the wear rate as it relates to both anteversion and tilt, to compare non cross-linked polyethylene with cross-linked polyethylene. We found that there was no relationship between tilt and ante-version on any wear indices. These data suggest that, despite having different mechanical properties to non cross-linked polyethylene, cross-linked polyethylene does not exhibit increased wear with conditions that increase edge loading.
Early migration of the acetabular and femoral component after total hip replacement has shown to be a good predictor of implant failure. The only current technique available for this measurement is RSA. An entirely new technique for the measurement of component migration and polyethylene wear has been developed. Required are a single CT of the patients’ pelvis and femur, and routine serial postoperative antero-posterior (AP) and lateral radiographs.
A CT scan of the patients pelvis and proximal femur is performed either pre or post-operatively. This CT is used to build a solid model of the patients’ bony anatomy. CAD models of the femoral and acetabular component are obtained from the manufacturer and all four solid models are imported into custom software. Ray tracer (RT) technology is the computer generation of images of a solid model placed between a camera and a screen. It has been adapted to reproduce the radiological setup used to take clinical AP and lateral radiographs. The four solid models (pelvis, acetabular component, femoral component, femoral shaft) are each placed in the RT. Manipulation of each solid model is performed (6 degrees of freedom, x, y, z translation, and rotation about the x, y, z axis) using Artificial Intelligence, until an outline of the solid model generated by the ray tracer is identical to the outline of the AP and lateral radiograph of that patient. Change in relative positions of each solid model over time (pelvis acetabular component represents acetabular migration, acetabular component femoral stem represents polyethylene wear, and femoral stem femur represents femoral migration) are recorded. Validation to measure accuracy of the technique has been performed using computer models, and femoral and acetabular prostheses implanted into a cadaver.
Despite significant variations in the position of the pelvis and leg during the obtaining of post-operative radiographs, this new technique was able to measure polyethylene wear and component migration with accuracy similar to that of RSA (0.25 mm in the AP plane).
Further testing and validation is required, but this technique offers promise for the future in being able to retrospectively measure component migration and poly-ethylene wear, using a single CT scan and routine clinical postoperative radiographs.
Management of massive acetabular defects in revision hip arthroplasty is challenging. The current generation reconstruction cages in combination with either morcellised or structural allograft bone have given promising results. However, a significant number fail due to failure of biological fixation of the cage, resulting in fatigue fracture of the cage. Trabecular metal has the potential to enhance biologic fixation. The purpose of this paper is to introduce this new surgical technique of combining a cage with a shell of trabecular metal and present the early results.
Fourteen patients (mean age 63, range 45 to 82 years) with massive contained defects underwent revision arthroplasty with a cup cage by the senior author (AEG). Complications, functional status (WOMAC, Oxford hip score and SF36) and radiographs were assessed. Post operative radiographs were assessed for evidence of construct migration, resorption and or remodelling of allograft bone. Remodelling was defined by the presence of bony trabeculae crossing the allograft host junction. Lucent lines were assessed. Allograft resorption was defined as loss of graft height on comparable radiographic views. An implant was defined as loose if there was evidence of construct migration or component fracture.
The mean follow up was 21 months (range one to 38 months). Complications included one death and one recurrent dislocation requiring revision to a capture liner. Average pre and post operative WOMAC scores were 61 and 17 points respectively. Oxford hip scores were an average of 45 pre-operatively and 24 post-operatively. SF-36 averaged 351 pre-op and 601 post-op. All implants were stable. Minor radiolucent lines were found around the inferior flange of the cage in six patients. Minor graft resorption occurred in two patients. All but one showed graft remodelling. All patients were ambulant.
The early results of this new technique for treating a complex problem show excellent rates of initial implant stability and bone graft remodelling.
The Morscher Cup is an acetabular component that was popular in the Bay of Plenty Region in the early 1990’s. It is an implant for which there are limited follow up results published in the international literature. Concerns have been raised that in some centres there has been marked, ballooning acetabular bone damage or osteolysis and that the implant may be associated with a higher dislocation rate. This paper will present the 13 – 15 year follow up in patients from Tauranga.
Ethical approval was gained from the Northern Region Y Ethics Committee. Patients who had had a Morscher Cup acetabular component in Tauranga from January 1992 until December 1994 were identified using the Bay of Plenty District Health Board NHI coding system and hospital logbooks. They were then invited to take part in the research which involved completion of WOMAC, Oxford hip score and SF 12 questionnaires, clinical review and an X-ray.
Of 81 patients with 91 Morscher Cup acetabular components implanted during the study period 62 patients with 70 Morscher Cup acetabular components were eligible for the study. Of these, 46 patients were available for clinical review, the remainder of the patients having passed away prior to final follow up. The average age at time of surgery for patients available for final follow up was 58 years. The average length of follow up was 13.7 years. The average Oxford hip score and WOMAC were 34.8 and 17.8 respectively. The average SF-12 PH was 40.9 and the average SF-12 MH was 54.8.
The Morscher Cup is an acetabular component that is still commonly used in New Zealand. The 13 –15 year results indicate that patients in this study are satisfied with their implant, but there is a lack of published data to compare them to other patient groups who have had a Morscher Cup acetabular component.
The Birmingham Hip Resurfacing (BHR) has become increasingly popular for young active patients with severe OA of the hip. Although it has been in use in the UK since 1991, none were performed in NZ until late 2004. We have reviewed our initial results & have compared them to a similar group of patients who received conventional total hip replacement (THR) with ceramic-on-ceramic bearings.
All patients aged 65 years or less undergoing either BHR or ceramic-on-ceramic THR under the care of the 2 senior authors (DRT & SAE) between October 2003 & July 2006 were included in the study. Patients were assessed pre- & post-operatively clinically & by questionnaires including the Harris Hip (HH) score & modified University of California Los Angeles (UCLA) activity score. Patients were also asked about activity levels prior to their hip symptoms.
59 BHR (38 resurfacings & 21 modular) and 55 THR were performed. 3 BHR & 1 THR patients were not able to be reviewed giving 97% follow up at 6–39 months. 3 patients had minor superficial wound infections (1 BHR & 2 THR). 1 BHR dislocated in recovery but has since been stable. 1 BHR has recently been revised for deep infection. We have had no peri-prosthetic fractures. BHR patients were slightly younger & were more active than the THR patients both pre- and post-operatively. Both group’s HH & UCLA scores improved significantly with surgery. BHR patients had a slightly greater improvement in HH score, but this failed to reach significance. When patients with single joint disease were considered, THR patients remained less active than prior to their hip symptoms whereas the BHR group’s activity scores matched their pre-disease level. All but 2 BHR patients and all of the THR patients were satisfied with their result at the time of review.
Our initial experience with the BHR has been positive. Although we have achieved excellent results with both the BHR and with ceramic-on-ceramic THR, the results of the BHR do seem superior in relation to post operative activity levels. The two groups were, however, non-randomised and did differ with respect to age & activity levels, so these comparative results should be interpreted with some caution.
Cement-less femoral fixation in revision hip arthroplasty offers advantages over cemented femoral revision with evidence of lower rates of both revision and impending prosthesis failure. Intermediate-term data suggests that extensively-coated stems provide reliable fixation by obtaining in-growth and stability in the healthier bone located more distally in the femoral shaft. We report the results of femoral stem revisions performed by a single surgeon at our institution using an extensively-coated, cement-less femoral component.
A retrospective review of notes and radiology was performed on all patients who underwent femoral revision by a single surgeon between January 1994 and March 2004, with a minimum follow up of 24 months. Patients were identified using a dedicated database and the New Zealand National Joint Registry. All patients were operated on using the same technique and received a Solution femoral stem (De Puy, USA). Each patient’s level of function was assessed using the Oxford Hip Score. Radiographic assessment was performed using Engh criteria for fixation and stability of porous coated implants.
67 Solution stems were inserted into 64 patients. Thirty-six patients (52%) were male. Mean age was 70.5 years (47–86). Mean follow up was 57 months (24–145). The most common indication for revision was osteolysis and/or polyethylene wear (75%). There were no failures of the femoral component requiring re-revision. 65 stems (97%) showed definite or suspected bony in-growth on radiographic review. The mean Oxford Hip Score was 27.3 (12–44).
Five cases (7.5%) developed significant complications requiring return to the operating theatre: one deep wound infection, two recurrent dislocations and two loose or mal-positioned acetabular components. The latter four cases required acetabular revision.
Previous reports have shown good results from the use of extensively porous coated cylindrical stems in revision hip arthroplasty. Our results show the Solution stem to be a reliable femoral revision stem with good medium-term results and a low rate of complications.
The Morscher press fit acetabular component is a monobloc cup with the polyethylene bonded directly to a titanium mesh shell. There is little published data on the longevity of the Morscher cup apart from the designer’s series. It has been quite widely used in New Zealand since its introduction in 1993. The aim of this retrospective study was to provide an independent mid-term audit of the results of this cup in the New Zealand population.
A retrospective review was undertaken of all Morscher cups implanted at Dunedin Public Hospital or Mercy Hospital by 5 orthopaedic surgeons between 1994 and 1998 with a minimum follow-up of seven years. Clinical and radiological survey was performed with standardised scoring systems. A new method for measuring linear cup wear was developed due to the unusual geometry of the Morscher cup.
136 hips were replaced in 121 patients during the study period 101 were performed in private and 35 in public. Our follow up ranged from 7 to 11 years (mean 8.69). There were 73 males (85 hips) and 48 females (51 hips). The average age of the patients was 57.5yrs (SO 24.97). Pre operatively the mean Merle d’Aubigne score was 9.4 (SO 4.02) and post operatively it was 17.4 (SO 1.58 (p< 0.0001).
There were 2 early revisions: one at 3 days for instability post-operatively and one for an unrecognised intra-operative femoral fracture. One hip required a two stage revision for deep infection at 3 years. Two hips have been revised for polyethylene wear and osteolysis at 7 yrs and 9 yrs and one hip required bone grafting of a large acetabular osteolytic lesion with retention of the cup. A further 4 patients have significant osteolytic defects and 2 have minor osteolytic lesions.
Wear measurements in the unrevised hips have shown a mean linear wear rate of 0.079mm/yr (range 0.000 to 0.222mm). 33% of these hips have a wear rate of > 0.1 mm/yr and 25% have a wear rate of < 0.05mm/yr.
We have found excellent clinical results with the use of the Morscher cup in this relatively young and active cohort. A small group of patients, however, have shown higher wear rates or osteolysis, and we emphasise the importance of continuing radiological review.
Proximal tibial bone density (BD) is a key determinant in the migration of implants following total knee arthroplasty (TKA). CT-osteodensitometry offers three-dimensional, volumetric analysis of both cortical and cancellous regions and has been shown to be both accurate and reliable about the hip.
The primary objective of this study is to assess differences in the bone remodelling pattern (tibial segment) of patients operated on using fixed or rotating platform, using CT-osteodensitometry. The hypothesis is that the presence of a rotating platform optimises stress distribution along the proximal tibia, resulting in reduced proximal bone remodelling of tibia. The secondary objective is to correlate the osteodensitometry and clinical data at follow-up.
Following completion of the initial assessment and after obtaining written informed consent, the patients were randomly allocated to either a PFC Sigma fixed bearing or a PFC Sigma rotating platform (mobile bearing) total knee system (DePuy, Leeds, UK). Clinical follow-ups were performed at three months, one year, and two years after the index operation. CT scans were performed immediately post-operatively and at one and two years respectively. 52 knees (47 patients) were randomised for cemented TKR management using rotating or fixed tibia platform and followed up at one and two years.
At the two year follow-up, the knee function and patellar scores were comparable in both groups. There were no radiographic signs of loosening, and no revision surgery was performed. Sequential BD measurement from post-operative baseline to two year follow-up showed minimal differences between the fixed and rotating platform implants. Bone density assessment showed a 20% mean loss of cancellous BD and minimal changes of cortical BD, with little differences between the two groups. Loss of cancellous BD appears progressive.
In conclusion, this study shows that the mode of fixation of the TKR polyethylene liner does not influence bone remodelling of the proximal tibia after surgery. This is the first study performed to assess separately cortical and cancellous BD changes in THR. There are no data in the literature for comparison.
There is a renewed interest in unicompartmental knee arthroplasty. The present report describes the minimum ten-year results associated with a – unicompartmental knee arthroplasty design that is in current use.
Sixty-two consecutive unicompartmental knee arthroplasties that were performed with cemented modular Miller-Galante implants in 51 patients were studied prospectively both clinically and radiographically. All patients had isolated unicompartmental disease without patellofemoral symptoms. No patient was lost to follow-up. Thirteen patients (13 knees) died after less than 10 years of follow-up, leaving 38 patients (49 knees) with a minimum of 10 years of follow-up. The average duration of follow-up was 12 years.
The mean Hospital for Special Surgery knee score improved from 55 points preoperatively to 92 points at the time of the final follow-up. Thirty-nine knees (80%) had an excellent result, six (12%) had a good result, and four (8%) had a fair result. At the time of final follow-up, 39 knees (80%) had flexion to at least 120 degrees. Two patients (two knees) with well-fixed components underwent revision to total knee arthroplasty, at seven and 11 years, because of progression of patello-femoral arthritis. At the time of the final follow-up, no component was loose radiographically and there was no evidence of peri-prosthetic osteolysis. Radiographic evidence of progressive loss of joint space was observed in the opposite compartment of nine knees (18%) and in the patello-femoral space of seven knees (14%). Kaplan-Meier analysis revealed a survival rate of 98.0% +/−2.0% at ten years and of 95.7% +/− 4.3% at 13 years, with revision or radiographic loosening as the end point. The survival rate was 100% at 13 years with aseptic loosening as the end point.
After a minimum duration of follow-up of 10 years, this cemented modular uni-compartmental knee design was associated with excellent clinical and radiographic results. Although the 10 year survival rate was excellent, radiographic signs of progression of osteoarthritis in the other compartments continued at a slow rate. With appropriate indications and technique, this uni-compartmental knee design can yield excellent results into the beginning of the second decade of use.
The purpose of this study was to determine the benefit and risk of NSAID-based prophylaxis for ectopic bone formation amongst patients undergoing total hip replacement (or revision) surgery.
A double-blind randomised placebo-controlled clinical trial, stratified by treatment site and surgery (primary or revision), was conducted in 20 orthopaedic surgery centres in Australia and New Zealand. 902 patients, undergoing elective primary or revision total hip replacement surgery, were randomly allocated to 14 days treatment with ibuprofen (1200mg daily) or matching placebo commenced within 24 hours of surgery. Patients were only excluded if there was, in the opinion of the responsible physician, a definite indication or contra-indication for treatment with an NSAID during the 14 day study treatment period. Outcomes were assessed six to 12 months after surgery and included changes in self-reported hip pain and physical function (WOMAC), physical performance measures and radiographic evidence of ectopic bone formation.
There was only a 6% loss to follow-up for self-report measures and a 12% loss to follow-up for radiographs. Six to twelve months after surgery, there were no significant differences between the ibuprofen and placebo groups for improvements in hip pain (mean difference, 95% confidence interval: −0.1, −0.4 to 0.2, p=0.6) or physical function (−0.1, −0.4 to 0.2, p=0.5), despite a much reduced risk of ectopic bone formation (relative risk 0.69, 95% confidence interval 0.56 to 0.83) associated with ibuprofen. There was a significantly increased risk of major bleeding complications during the admission period (2.09, 1.00 to 4.39)
These data, from the largest-ever trial of prophylaxis against ectopic bone formation, do not support the use of routine NSAIDs-based prophylaxis for patients undergoing total hip replacement surgery.
There remains controversy as to whether computer-navigated TKA improves the overall alignment of the knee prosthesis. The aim of this study was to determine whether computer-assisted total knee arthroplasty provides superior prosthesis positioning when compared to a conventional jig-assisted total knee replacement.
A prospective controlled study comparing computer navigated and conventional jig-assisted total knee replacement in 23 patients who underwent bilateral TKA was undertaken to determine if there was any significant difference in component position. The 23 patients (46 knees) were randomised to receive one conventional jig-assisted total knee replacement, and a contra lateral computer-assisted total knee replacement. A single experienced knee surgeon performed all procedures.
A quantitative assessment of the spatial positioning of the implant in the 46 total knee replacements was determined using a low-dose dual-beam CT scanning technique. This resulted in six parameters of alignment that were compared. A blinded, independent observer recorded all radiological measurements.
Median external rotation of the femoral component relative to the trans-epicondylar axis was −2 degrees in the computer-assisted group and −3 degrees in the jig-assisted group. Median femoral component flexion was identical in both groups at 0 degrees. Median valgus angulation of the femoral and tibial components was +1 degree and 0 degree respectively for the computer-assisted group and 0 degree and −1 degree for the jig-assisted group. Median posterior tibial prosthesis slope was +5 degree in both the computer-assisted group and the jig-assisted group.
Computer-assisted implantation of total knee replacements does not offer a significant advantage in prosthesis alignment. Low dose dual-beam CT scanning provides a three dimensional model of the lower limb, allowing accurate measurement of prosthesis alignment.
The purpose of the current study was to compare the results of the P.F.C. Rotating Platform Knee System and the P.F.C. Knee System in a randomised prospective study.
151 patients were enrolled in the study, totalling 172 knees, with 84 receiving fixed bearing and 88 receiving rotating platform knees. Patients were enrolled prospectively with preoperative assessment of the defined outcome measures including Knee society score, Oxford Knee Score, SF-36 score, WOMAC score, VAS pain score and ROM. These outcome measures were repeated at 6 months, 1 year and 2 years
At the two year follow up patients were assessed and results analyzed to see if there were any significant differences with regard to outcome measures. There was no statistically significant difference for the SF12, Oxford knee score or the VAS pain score. In the Knee Society Score a trend effect at the one year follow up (almost significant at p = 0.07) was seen with the rotating group scoring better in overall function than the fixed group. At the two year follow-up this difference between groups became significant (p = 0.05) and the rotating group had significantly better overall function than the fixed group.
The early results show a better functional score with comparable subjective outcome measures with regard to pain and ROM. The long term purported benefits of the rotating platform versus fixed will be watched with interest in the medium to long term follow up.
In Total Knee Replacement, over-sizing the femoral component may restrict knee flexion. If the AP dimension of the existing femur is in between component sizes, you should down-size the femoral component whenever possible.
Using the Triathlon Knee System the femoral and tibial component sizes were recorded for 140 consecutive knee replacements. For each procedure, the femoral component size was compared to the tibial component size and recorded as same size, one size down or one size up. The author’s component selection was then compared with 500 Triathlon knee replacements carried out during the same period by other surgeons
In the authors 140 cases, the femoral component was the same size in 96(68%), one size down in 33(24%) and one size up in 11(8%). This compared with other users (500 cases) where the femoral component was the same size in 360(62%), one size down in 51(10%) and one size up in 89(18%). Compared with other users, the author was more likely to downsize the femoral component 24% v 18% and less likely to upsize 8% v 18%. These differences were significant, p< 0.05.
Anterior cruciate ligament reconstruction is a common procedure performed by orthopaedic surgeons. The procedure continues to evolve, with a trend towards more accurate reconstruction of the pre-existing anatomy. Single bundle reconstruction has been the gold standard, with good to excellent results returning many athletes to their chosen sports. Persisting functional instability and late degenerative changes are well described, encouraging several centres to attempt to improve upon the single bundle technique.
This is a technical paper examining the first 15 cases in a single surgeon series. Technical challenges unique to double bundle reconstruction will be discussed with suggestions on how to minimise problems. Tourniquet time, early complications and KT1000 measures will be presented.
The technical requirements of anatomic double bundle ACL reconstruction fall within the skill set of a competent arthroscopist. The transition can be simplified with a clear knowledge of the problems unique to this procedure.
The purpose of this study was to identify causes of failure and rates of revision of the Oxford prosthesis (OXF) in New Zealand, by reviewing and comparing the uni-compartmental (UKA) and total knee arthroplasty (TKA) data from January 2000 to December 2005, as recorded in the New Zealand National Joint Registry.
Eighty one orthopaedic surgeons performed 2006 Oxford UKAs (64% of all UKAs). The revision rate was 4.7%. This compared with a revision rate of 4.8% for all UKAs combined, and 1.6% for TKA. UKA (3122) made up 13% of all knee arthroplasties (24 260). The most common reasons for revision of the OXF were aseptic loosening (45%), unexplained pain (33%) and bearing dislocation (12%). Unexplained pain as the only reason for revision (33%) was significantly different (p = 0.001) from the TKA rate (23%).
Deep infection as a cause for revision was 0.20% for the OXF compared with 0.48% for TKA (p=0.07). The patient- generated Oxford scores at six months after operation were rated excellent or very good (Field et al, 2004) in 68% of OXF compared with 62% TKA patients (p = 0.001).
Five higher-use OXF surgeons (12 or more/year) performed 25.1% of the operations with a revision rate of 0.99%. Ten high- use surgeons (eight to 11/year) performed 28.1 % of operations with a revision rate 4.6%. Thirty medium-use surgeons (two to seven/year) performed 39.0% of the operations with a revision rate of 6.4%. Thirty-six low-use surgeons (one or less/ year) performed 7.8% of the operations with a revision rate of 8.3%. The difference in revision rate between the higher-use surgeons (one operation/month) and all the other three lower use groups was significant (e.g. p=0.0006 higher/low)
The early revision rate for the OXF was 2.9 times greater than that for TKA. However, higher-use surgeons (i.e. those performing one/month or more) had a revision rate comparable to TKA. Deep infection was lower and six month function scores were higher for OXF compared with TKA. Unexplained pain as the only reason for revision was significantly higher for OXF compared with TKA.
A post-clinical retrieval analysis was performed on 43 polyethylene tibial components of a contemporary total knee arthroplasty system with implantation duration between 12 and 80 months. Components were scored for eight potential modes of surface wear or damage on the top and back surfaces. Moderate backside wear of 4.1μm per year was documented by measuring the extent of manufacturer’s engraved lettering removal. Neither the topside nor backside score correlated with duration of in vivo function. No component experienced topside or backside delamination, cracking, or significant deformation. The greatest contribution to wear and damage score was pitting and scratching secondary to bone cement debris. The extent of both wear and damage experienced by these components was moderate, in comparison with that previously reported with older implant systems.
Septic arthritis of the knee is an uncommon complication of arthroscopic anterior cruciate ligament reconstruction, with a reported incidence ranging from 0.14% to 1.7% in recent publications. In this study, we assess the clinical presentation, management and early outcome of patients with septic arthritis of the knee following anterior cruciate ligament reconstruction. Literature on this uncommon complication is sparse.
The North Shore and Auckland City Hospital Orthopaedic databases were searched and 13 patients were identified as having been treated for septic arthritis of the knee following anterior cruciate ligament reconstruction in the period from July 2002 to August 2006. Their clinical records were reviewed to compile information regarding their presentation and management. Five of these patients were also recalled for clinical follow-up at an average time of 16 months. We reviewed knee range of motion, stability, functional testing in vertical and horizontal jumps and radiographic changes. Clinical outcomes were further assessed using the Tenger, Lysholm and International Knee Documentation Committee Scores.
The patients reviewed had a mean age of 26 years and presented to hospital at an average of 16 days after their autologous ACL reconstruction surgery. All had initial elevation of inflammatory markers with a mean CRP of 189mg/L (68 – 295) and mean ESR of 71mm in one hr (10 – 112.) Mean peripheral WCC on presentation was 12.3 (9.5 – 22.4.) Initial knee aspirates were performed on all patients and yielded a mean specimen WCC of 60,900 x 106/L. Of the 13 patients, six had S. epidermidis, three had S. aureus, two Propioniobacterium acnes and one Serratia marcescens. No organism was cultured from one patient’s aspirate. The study patients underwent an average of two surgical interventions, the first being arthroscopic washout in each case. Six patients subsequently underwent open knee joint washouts, four of these having their cruciate grafts removed.
Of the five patients recalled for clinical review, three rated their IKDC knee performance as being significantly worse than their uninjured side. Mean IKDC scores were 63.5 for the affected knee and 97.3 for the contralateral knee. Mean Lysholm knee score was 71.8 at follow-up. Tenger scores prior to ACL reconstruction averaged 4.4, compared to 5.6 on review. Radiographs demonstrated evidence of arthritis that was not apparent pre-operatively in four of the five review patients. These individuals lacked an average 2.8 degrees of extension and 13.4 degrees flexion in comparison to their contralateral knee. Two patients demonstrated clinical instability on examination. The mean single-legged hopping distance was 62.9% horizontally and 96.4% vertically, when comparing the affected knee to the contralateral side.
Staphylococcus epidermidis was the most common pathogen identified in this study. Most patients presenting with this complication will require two or more operative procedures and a prolonged course of intravenous antibiotics. The symptomatic and functional outcomes of septic arthritis associated with recent ACL reconstruction are highly variable, but were found to be worse in those patients requiring graft removal to eradicate their infections. Despite their young age, most of those patients undergoing clinical review had radiographic evidence of early osteoarthritis.
Arthroscopic controlled retrograde drilling of femoral and tibial sockets and tunnels using a specially designed cannulated drill pin and retrocutter (Arthrex Inc, Naples FL.) provides greater flexibility for anatomical graft placement and in revision cases avoids previous tunnels and intra osseus hardware. Inside out drilling of femoral and tibial sockets minimises incisions and eliminates intra articular cortical bone fragmentation of tunnels rims common to conventional antegrade methods. This technique is also ideal for skeletally immature patients since drilling and graft fixation through growth plates may be avoided. Initial tunnel-referencing cannulated drill guide pin placement is carried out from outside-in. This technique (out-in/in-out) combines the advantages of the two-incision and the one-incision technique. In fact it permits us, as in the two-incision technique, to drill a pin guide from outside to inside in order to obtain the correct anatomical insertion of the ACL, otherwise not reproducible from inside-out.
Since November 2004 our preferred technique for hamstring (autogenous quadrupled semitendinosis/ gracilis) ACL reconstruction incorporates the above mentioned femoral socket creation. In recent years, arthroscopically assisted ACL reconstruction has become the procedure of choice. Initially, arthroscopic techniques required two incisions for outside-in drilling of bone tunnels, but there has been a trend toward using a single incision with inside-out of the femoral tunnel. Those who advocate the two-incision technique state that they do so primarily because they believe that the two-incision procedures makes accurate femoral tunnel placement easier. Harner found no difference in tunnel placement using the two techniques, while Schiavone found that the inside-out femoral tunnels were significantly more vertical in the one-incision procedure.
We have performed two-incision ACL reconstruction routinely since 1977, with very favourable results. The recent variation in our technique affords a reduction in morbidity, associated with improved cosmesis and quicker post-operative recovery. One factor related to our success appears to be a more anatomically positioned femoral tunnel, which in our hands, is difficult to accomplish with the single incision trans-tibial femoral socket creation. The retro-drill technique allows preparation of the correct anatomical femoral and tibial socket or tunnel, either with a very small lateral skin incision or without any skin incisions if the surgeon is using an allograft, and appears to represent a promising future technique in ACL reconstruction.
MACI Cartilage Transplantation has been performed in New Zealand for the last three years for patients with isolated articular cartilage defects who have failed a microfracture technique. Ten patients have undergone this procedure. Patients were evaluated by an independent research assistant preoperatively and at 6, 12 and 24 months. Visual analogue pain score, ICRS score, WOMAC score, KOOS score, IKDC score, Tegner score and SF 36 were collected at all time points. An MRI scan was performed in all patients at 12 months.
So far, ten patients have a minimum of 12 month data, while two have been followed to 12 months. There has been an improvement in visual analogue pain score, ICRS score, WOMAC score, KOOS score, IKDC score and SF 36. No procedures have failed. All MRI scans showed restoration of articular cartilage.
In conclusion, early results are encouraging. The rehabilitation is long, thus 12 month data do not give an accurate outcome measure. Ongoing evaluation is occurring
The purpose of the study was to describe the normal anatomy of glenoid labrum. Twenty dry bone scapulas and 19 cadaveric shoulders were examined. Light microscopy was performed on 12 radial slices through the glenoid.
An external capsular circumferential ridge, 7–8mm medial to the glenoid rim marks the attachment of the capsule. A separate internal labral circumferential ridge 4mm central to the glenoid rim marks the interface for the labrum and articular cartilage. A superior-posterior articular facet contains the superior labrum. Two thirds of the long head of biceps arise from the supraglenoid tubercle, the remainder from the labrum. The superior labrum is concave and is loosely attached to the articular cartilage and glenoid rim. In contrast the anterior-inferior labrum is convex, attaches 4mm central to the glenoid rim and has a strong attachment to articular cartilage and bone.
The anatomy of the superior and anteroinferior labrum are fundamentally different. Suture anchor repair of the superior labrum should be 7mm medial to the glenoid rim whereas the anterior-inferior labrum should be repaired to the face of the glenoid. By defining the normal anatomy of the superior labrum, pathological tears can be identified.
High tibial osteotomy (HTO) is a surgical procedure that involves cutting the proximal tibia in an attempt to change the weight bearing axis from the medial to the lateral compartment of the knee. It is especially appropriate for young and middle age active patients who have a primary, degenerative arthrosis involving the medial compartment in a malaligned limb, and causing pain and functional limitation.
Over the last ten years, the indications for HTO have expanded to include patients with initial cartilage damage that can be treated with one of the new cartilage repair techniques and patients with chronic ligament deficiency, associated with a varus malalignment. The opening wedge HTO is a relatively new technique, compared to the Coventry’s lateral closing wedge osteotomy. It turns upside down the method of correction of the varus deformity, adding a wedge medially and is based on a dedicated system of instruments and plates (Arthrex, Naples, Florida).
In the international literature, many series have shown encouraging middle-term results following HTO. The majority of authors agree that there is a gradual decline in the quality of the result with time. In general, HTO has been demonstrated to be effective for approximately five years in 85–90% of the patients, and for about two thirds (65%) of them over ten years from the operation. Aglietti, in a review of 139 knees that had HTO, noted excellent and good results in 64% of the knees after a follow-up period of at least 10 years. However, a tendency for results to deteriorate with time was observed, with satisfactory results in 64% with more than 10 years follow-up evaluation, 70% of the knees with six to 10 years evaluation and 87% of the knees with two to five years evaluation. Insall (21) reported 97% of good results at two years, 85% good results at five years and 63% good results at nine years. At nine years, deterioration in these patients was primarily the result of time, and not recurrence of deformity. In contrast with Insall, other authors have reported instead that deterioration of results is due to recurrence of deformity.
From our personal experience, we have a series of 55 patients, six bilateral, operated on between 1992 and 2000, with the opening wedge technique, follow-up six to 14 years. The average age was 49 years, 32 men and 23 women. The results were evaluated using the International Knee Documentation Committee (IKDC) rating scale and the Hospital for Special Surgery (HSS) scoring system. Pre-operatively, 38 patients belonged to group “C” and 17 to group “D” of the IKDC rating scale. At follow up, all the 38 patients of group C passed to group B. Of the 17 patients in group D, 13 passed to group C and 4 to group B. All the patients improved their conditions at least one category. The same results evaluated with the HSS score system resulted in 33 knees poor and 22 fair before the HTO. At follow up, we had 14 excellent, 38 good and 3 fair. These particularly satisfying results may be influenced by the improper use of the HSS score system, which was designed to evaluate results in prosthetic replacement surgery.
Reverse shoulder arthroplasty has been used to treat arthritis of the shoulder with no rotator cuff. The purpose of this study is to review the short term outcome of reverse shoulder arthroplasty performed at North Shore Hospital.
Between 2003 and 2007, 54 consecutive patients were treated with the SMR reverse shoulder prosthesis. Patients were assessed using the visual analogue pain score, patient satisfaction rating, the American Shoulder and Elbow Society Shoulder score, the Oxford shoulder score, the Short Form – 12, and by radiographs. We also reviewed clinical and radiographic complications.
Nine patients underwent surgery for fracture, two for chronic dislocation and 43 for cuff tear arthropathy, including four revisions. The mean age at surgery was 77.8 years (range 54–91 years). 53 of the implanted prostheses were SMR (Lima Orthotec) and one was a Delta (De Puy). Patient assessment is still in progress, but findings so far show very favourable early outcomes.
We report a large consecutive series of patients who had the reverse prothesis at North Shore hospital. To the best of our knowledge, there has been no previous publication of results of the SMR reverse prosthesis
Reverse total shoulder replacement is a viable surgical option for Cuff Tear Arthropathy. Short term results have been promising. Longer term follow-up has demonstrated a high rate of scapular notching. This is attributed to mechanical impingement between the humeral cup and scapular neck when the arm is fully adducted. The long term sequelae of scapular notching are unclear but there is concern that it may compromise fixation of the glenoid component and affect functional outcomes.
Design modifications to address this problem include the newly available eccentric glenospheres and larger diameter glenospheres. These glenospheres are designed to offer greater ranges of motion and theoretically may reduce the risk of impingement and notching. The purpose of this biomechanical study is to demonstrate the difference in range of motions with each design of glenosphere. To our knowledge there is no published literature evaluating this design differences.
The SMR (Lima Orthotec) reverse total shoulder prothesis was implanted into a synthetic bone model (Sawbones, Pacific Laboratories, Vashon, Washington). Four different types of glenospheres (Standard 36 mm, Eccentric 36 mm, Standard 44 mm, Eccentric 44 mm) were then implanted into the same model which was fixed on a measurement table. The precision coordinate measurement device (FARO-Arm, SO6/Rev22, FARO Technologies Inc., Lake Mary, Florida) was used to establish the centres of rotation and ranges of motion.
To date, the collection of data has just been completed, but the data are yet to be analysed. In conclusion, this is a biomechanical study evaluating the ranges of motion and risk of notching, comparing different designs of glenospheres in Reverse Total Shoulder Joint Replacement.
At the New Zealand Shoulder and Elbow Society Meeting in 2005, it was decided to set up a national registry to look at the outcomes of rotator cuff repair in New Zealand. National Joint Registries have produced very powerful information on the performance of joint replacements, not just in the hands of the designer but for all surgeons. The patient numbers in these Registries have allowed powerful information to be derived which has had a significant impact on local practice.
A nationwide registry on rotator cuff repair in New Zealand has the potential to provide similar powerful information. This is an area in which there has been rapid change over the last five years particularly with regard to surgical approach whether it be open, mini-open or arthroscopic and uncertainty remains as to what is best ‘best practice’. Surgeons are unwilling to invest time and effort into mastering sometimes difficult new procedures unless significant benefit can be demonstrated. Aspects addressed include anchors v. traditional drill holes in bone, anchor type, suture type and configuration, length of immobilisation, post-operative regime, effects of smoking and NSAIDs, on outcome and outcome versus size of tear.
A pilot study is being undertaken to ensure the questionnaires are workable and the system will run smoothly. Early results of the pilot study will be presented.
The treatment of supracondylar humeral fractures in children continues to evolve. The currently fashionable treatment for displaced fractures is closed reduction and the insertion of at least two K-wires. This usually requires the patient to have a second surgery to remove the K-wires, and may result in significant scarring. The senior author has used the straight arm method to treat displaced supracondylar fractures. We have reviewed the long term results of seven children treated by the straight arm method. No patient had a scar, no patient had a cubitus varus and all children regained a full range of movement. This method offers excellent results with no risk of iatrogenic nerve injury, scarring, or second surgery.
Avulsion of the distal biceps tendon is an uncommon clinical entity accounting for 3% of all biceps tendon injuries. Various surgical techniques for its repair have been reported, however, the optimal technique is unknown. The two-incision technique is used by three upper limb surgeons at North Shore Hospital. There has been some concern regarding the risk of heterotopic bone formation with this technique. We present a review of a series of patients with distal biceps tendon ruptures treated with the modified two-incision technique to identify and describe any complications that we encountered and also assess the clinical, functional and radiological outcomes of our patients.
Over a 4-year period from 2002–2006, 42 distal biceps tendons repairs using the two-incision technique were identified from the hospital database. All 42 patients were males with an average age of 51.9 years. Patients were followed-up prospectively and reviewed at a clinic where they filled out the SF-12 questionnaire and a Mayo Elbow Performance Score was assessed. Clinical assessment was carried out with regards to their range of flexion-extension and their pronation-supination. All peripheral nerves were examined. Isokinetic elbow flexion-extension and forearm pronation-supination were measured and compared to the unaffected extremity. X-rays were taken to identify heterotrophic ossification or proximal radioulnar synostoses.
Our review, so far, indicates a good clinical and functional outcome in most of our patients. We identified one patient with heterotrophic bone formation requiring excision. Two patients had a transient lateral ante-brachial cutaneous nerve parasthesia and two patients had re-ruptures following surgery.
This study represents a relatively large series of patients. Our results reveal that the two-incision technique is an effective surgical option for the repair of ruptured distal biceps tendons. We found that radioulnar synostoses and heterotrophic ossification are rare following the muscle splitting modification of the two-incision technique.
The spectrum of pathoanatomy in collision athletes with shoulder instability is wide, with a high incidence of extended labral lesions and associated intra-articular injuries. The ‘collision shoulder’ describes an injury sustained by direct impact to the shoulder without dislocation, but with extensive labral damage and a high incidence of other intra-articular pathology and neurological symptoms.
One hundred and eighty-three collision athletes (rugby and rugby league) were treated for labral injuries related to their sport in three different centres. Details of the mechanism of injury and findings at surgery were recorded. Only 60% of athletes in the series presented following a documented dislocation or subluxation episode of the shoulder. An additional pattern of injury was recognised in the remaining athletes involving a direct impact injury to the shoulder. In these athletes the clinical symptoms and signs were less specific but there was a high incidence of ‘dead arm’ at the time of injury (72%).
The spectrum of pathology in this series was wide with a high incidence of associated intra-articular lesions. In those athletes with an impact type of injury without dislocation there was more extensive labral pathology with a high incidence of posterior labral tears (50%). The incidence of associated chondral lesions was similarly very high but significant bony pathology was less common than in the dislocation group (11 % versus 26%). Elite athletes had less frank dislocations but were more likely to sustain neurological injury, posterior labral tears, SLAP lesions and cartilaginous and capsular injuries.
The incidence of all lesions in this series of collision athletes is higher than those previously published. These lesions often occurred in the absence of a frank dislocation (the ‘collision shoulder). It is important to anticipate additional pathology when planning definitive management in these patients, with surgery tailored to the specific lesions found. The athlete with an impact type of injury without dislocation can do well following surgery, with a high rate of return to contact sport, either at the same or a higher level.
Femoral head fractures i.e. Pipkin fractures are uncommon injuries and there are very few large series in literature with reported outcomes. There remain many controversies regarding diagnosis and management. This study, which is the largest single surgeon experience, is an attempt to get answers to some of these controversies.
This series is an analysis of 51 patients with femoral head fractures. There were 44 males and seven females. The right side was involved in 36 and left in 16 patients. According to Pipkin classification these were 13 Pipkin-I, 27 Pipkin-11, three Pipkin-111 and eight Pipkin-IV fractures. Thirty-two patients were managed by surgical intervention. The surgical approach was posterior in Pipkin-I and in seven cases of Pipkin-II fractures. Another eight Pipkin II cases were managed surgically by anterior Smith-Peterson approach while another eight fractures were accessed by posterior approach with flip osteotomy. The Pipkin III and IV cases were managed using surgical approaches that varied depending on the pattern of associated acetabular injury. The fractured fragment, if small, was excised and, if large, was re-fixed using small fragment partially threaded cancellous screw. Follow-up of two to eight years was available in 39 cases.
Using Thompson and Epstein criteria, 26 patients were rated as having good results, eight fair and five poor results. Early osteoarthritic changes were seen in five patients, avascular necrosis of the femoral head in three patients and one patient had re-fracture in same hip during an epileptic fit with subsequent fixation problems. Of four patients with sciatic nerve injury, two had persisting motor deficit. There was one case of heterotopic ossification.
Most Pipkin-I fractures can be managed by closed reduction, Pipkin-II fractures usually require ORIF. The best results have been obtained by a Smith-Peterson approach if the hip has already been reduced, but posterior approach with flip osteotomy offers the best exposure if the hip is still unreduced. Pipkin III patients need hip replacement if presentation is late, while ORIF gives acceptable outcome in Pipkin IV fractures.
The purpose of this study was to evaluate the results of LISS fixation of distal femur fractures
This is a single-centre review of 64 consecutive LISS plates used for distal femoral fractures over 5.5 years. No patients were excluded and all were followed for a minimum of one year (mean 37 months). Primary outcomes were time to union, knee ROM, Knee Outcome Survey Activities of Daily Living Scale and SF-36 scores. Secondary outcomes were fracture alignment, additional surgery and complications.
Sixty-four fractures were followed in 62 patients with a bimodal distribution of age (mean 66 yrs, 14–98 years). Two major subgroups were young patients (55 and under) with high-energy fractures, most common in men (12:4) and elderly patients with insufficiency or peri-prosthetic fractures, more common in women (11:35). Twenty-two patients died prior to clinical follow-up in the study, but only eight of these died prior to radiological and clinical bony union. No other patients were lost to follow-up. Ninety-four percent of patients achieved within 10 degrees of full knee extension (mean 1.4 degrees), whilst 74% achieved knee flexion > 100 degrees and all achieved 90 degrees. Mean union time was 6.8 months and there was one infected non-union. There were 28 re-operations in 17 patients. Ten were for removal of metal-ware, four required bone grafting and two had revision of fixation.
LISS fixation is a reproducible technique, producing reliable union, low re-operation rates (other than metal-ware removal) and good restoration of knee function. LISS is good for both high and low energy injury patterns and works well in the presence of both knee and hip replacements. We recommend bi-cortical proximal fixation in osteoporotic bone.
The goal of this study was to determine which of two techniques for the treatment of peri-prosthetic femoral shaft fractures has the greatest torsional integrity. The study designed was a laboratory study, using 13 matched pairs of embalmed femurs. The femurs were implanted with a cemented total hip prosthesis, with a transverse osteotomy distal to the stem. These fractures were fixed either with a metal plate with three proximal unicortical screws and three distal bicortical screws or with three proximal cables and three distal bicortical screws. The fracture fixation was tested to failure in torsion. The pattern of failure and torsional limits were recorded.
There was no significant difference to failure level between the two constructs. Failure with the proximal unicortical screws was usually catastrophic versus non-catastrophic with proximal cables. The femurs were significantly more likely to fracture in internal rotation.
Treatment with proximal cables has the same load to failure in torsion but significantly less complications than with unicortical screws, in agreement with the literature. The findings of the construct being weaker in internal rotation, appears to be a new finding and an area of possible new research.
Osteoporosis is common in elderly patients admitted to orthopaedic units with fractures. Fragility fractures place a large burden on health expenditure. Orthopaedic units are in a position to identify patients who require bone density assessment and possible treatment of osteoporosis. Previous surveys of orthopaedic surgeons have shown a wide variance in their perceived role in this.
This study was a retrospective note review of 305 patients aged over 55 years with a fragility fracture, who were admitted under the orthopaedic service of eight New Zealand hospitals. Notes from any subsequent rehabilitation unit admission were also reviewed, if available.
The mean age was 80.6 years (range 55–104). Seventy seven percent were female. The most common fracture was of the hip (61.6%). Two hundred and thirty-six patients (77.4%) were not taking osteoporosis medication at time of admission, 2.5% of these had a bone mineral density assessment ordered and 11.9% had osteoporosis treatment started, giving a combined intervention rate (investigation or treatment) of 14.4%. A visiting orthogeriatric service initiated treatment in 82.1% of cases. Osteoporosis was listed on the discharge summary in 31.8% of patients who were taking osteoporosis treatment on admission and in 10.7% of patients who had treatment started.
Management of osteoporosis is mostly neglected by New Zealand orthopaedic units. This is similar to published data from other countries. Hospitals with the highest rates of osteoporosis intervention had an orthogeriatric service initiating the majority of treatment. Treatment started by the orthopaedic staff was not optimal. Osteoporosis is not identified in most documentation generated by the orthopaedic units.
As the population ages, we can expect to see more elderly patients with calcaneal fractures. Age alone does not reflect a person’s health or functional status, and should not, therefore, be used as a contraindication to surgical fixation. We report on the management of all patients over 65 years with calcaneal fractures receiving treatment at our institution over a 14-year period.
Seventy-three patients > 65 years old with 76 calcaneal fractures treated from 1990 to 2004 were identified from a trauma database. A review of clinical notes was performed; demographics, co-morbidities, mechanism of injury, associated injuries, and management data were collected. For patients receiving operative treatment the fracture classification, operative indications, treatment and outcomes were reviewed.
Twenty-seven patients with 29 fractures were treated without fixation, and 46 patients with 47 fractures were treated with fracture fixation. When compared with non-operatively treated patients, those treated operatively had lower mean injury severity scores (8.9 vs. 17.2) and fewer mean co-morbidities (1.0 vs. 2.2).
Fractures were treated operatively either with an extensile lateral approach, small incision fixation, or a push screw. Follow-up (two weeks to 50 months) was available on all patients treated operatively, and radiographic follow-up was available on 32 patients. Wound infection and persistent drainage was seen in three and two patients, respectively. There was one non-union. One subtalar fusion was required. Eleven patients subsequently required plate removal.
This retrospective review demonstrates that operative treatment of calcaneal fractures in carefully selected, elderly patients can result in good outcomes with acceptable complication rates. The complication profile for patients over 65 with calcaneus fractures appears to be similar to younger patients.
The management of peri-prosthetic fracture following total hip arthroplasty is difficult, requiring expertise in both trauma and revision surgery. With rising numbers of patients in the population living with hip prostheses in situ, their frequency is increasing, and controversy remains over their ideal management. The objective of this study was to review all peri-prosthetic fractures at a single institution to identify injury and treatment patterns, and their associated clinical outcomes.
Fifty-four peri-prosthetic fractures in 50 patients were reviewed to determine the relative frequency of fracture types, complication rates, and clinical outcomes. Patient data were obtained through review of the clinical notes and individual patient follow up. Clinical outcomes were evaluated using the Oxford Hip Score (OHS) and Harris Hip Score (HHS).
The fractures were classified using the Vancouver system, the majority of which were type B 1 (20) or type B2 (10). The mean time to union for all fracture types was 4.6 months. A high non-union rate was seen amongst fractures fixed operatively. Fifteen percent of fractures went on to develop loosening following treatment, suggesting under-recognition at the time of injury. The average HHS was 73.1 and OHS 30.3 for all fracture types, at a mean follow up of 3.3 years. Of the 15 patients treated with revision surgery, the most common complication was dislocation (27%).
Treatment of patients with peri-prosthetic fractures requires recognition of the challenging nature of these injuries, their associated poor prognosis, and high complication rate.
Intra-operative 3-D fluoroscopy has limitations, including low resolution images, little soft tissue information and small working volume. Fusion of 3D data sets (MRI/ CT) had been developed in pre-operative planners. We employed the same principle and developed a new technique of navigation with fused images of pre-operative MRI/CT and intra-operative 3D fluoroscopy.
Pre-op CT/MRI in DICOM was imported to the Stryker Leibinger Spine 3-D and segmentation of the intended bone performed. Patient tracker was mounted and 3-D fluoroscopy performed using Siemens ISO-C 3D. Fusion of CT/MRI with 3D fluoroscopy was performed using “surface matching image correlation” and this automatically registered the bone with MRI/CT. The fused images were then ready for 3D navigation procedures.
Nine patients were included in the series. There were eight fracture cases and seven performed with fused CT and 3-D fluoroscopy (two PCL avulsion fractures, two tibial plateau fractures, one femoral condyle fracture and three pelvic-acetabular fractures). Total of twenty-three screws had been inserted without complication. One tibial plateau fracture fixation and one core decompression for avascular necrosis of femoral head were performed with fused MRI to 3D fluoroscopy.
In conclusion, intra-operative 3-D navigated procedures with fused pre-operative MRI/CT and intra-operative 3-D fluoroscopy were all successful with (1) extended working volume (2) higher resolution images (3) more soft tissue information. We foresee more applications of this new technique in other areas of computer aided surgery
Motorcross motorbiking has seen a great upsurge in popularity since the year 2000 globally. With extreme sports come extreme injuries, characterised by high energy trauma patterns. 55% of all such injuries are orthopaedic in nature, with a significant proportion comprising foot and ankle injuries. In New Zealand, ‘recreational motorbiking’ as a category made up 2.3% of all ACC coded sporting injuries in the year 2002. At Middlemore Hospital we have seen a greatly increased number of motorcross injuries over the past decade. To date, there is a dearth of literature (particularly in Australasia) on this injury group.
The current study was a retrospective review of 208 episodes of trauma in 176 patients between February 1993 and June 2005, at Middlemore Hospital. Thirty-one of these trauma episodes in 30 patients were foot and ankle trauma (17% of patients, 15% of all trauma episodes).
The aims of the study were to describe the demography of the motocross injury patient population, any associations between modes of injury and resultant injury patterns and to identify any injury clusters peculiar to the motorcross foot and ankle injury subgroup. A better understanding of these factors will ultimately improve injury identification and management of motor-cross foot and ankle trauma at primary contact.
The study found that the majority of patients are male and Caucasian. The mean age was 26 years (range: 8–55 years). Seven of the 31 cases (22.5%) represented multi-trauma presentations. The majority of injuries occurred in group whereby a rider was ejected from bike (22/31). Twelve out of 31 cases had ‘polybone’ trauma in the foot (with all forefoot trauma being ‘polybone’ in nature) There was a clinically observed injury association between ankle and talus fractures. Four of 20 forefoot injuries required an operation, while 32 of 37 (86.5%) midfoot, hindfoot, ankle and intra-articular distal tibial injuries required operations.
We conclude that foot and ankle trauma represents a significant proportion of all orthopaedic motorcross trauma that is seen at this institution. Over one in five injuries involving the foot and ankle are multi-traumatic in nature, with rider ejection perhaps playing a role. Over four out of five injuries extending proximally from the midfoot required operative management. Foot and ankle motorcross injuries are frequently high energy in nature and their assessment requires a moderate index of suspicion for other bone injuries in the foot, as well as elsewhere.
An experimental study was performed in order to investigate methods of preparation and mechanical properties of a potential bone graft substitute. This new composite material consists of porous hydoxyapatite coated with oxidised cellulose.
Porous hydoxyapatite has excellent osteoconductive properties and promising strength characteristics. Drawbacks include its lack of osteoinductive properties and its brittle nature. Oxidised cellulose can be functionalised to provide binding sites for proteins, drugs and cells, which would allow for increased osteoinductive activity. It has good tensile strength. By creating a composite of these two substances, it was proposed that a graft substitute could be created.
Hydroxyapatite samples were formed by processing and sintering bovine cancellous bone. A method was devised by which cellulose was brought into solution and infiltrated into hydoxyapatite samples. The cellulose was then regenerated (cured) and oxidised.
Infrared spectrometry confirmed the desired chemical reactions took place and that oxidised cellulose was formed. Scanning electron microscopy confirmed that the three-dimensional structure of the hydroxyapatite was satisfactorily coated. Crush testing showed that infiltrated samples were less brittle and more likely to hold their shape than control samples.
Further development and testing is required to assess this composite material for its biological activity and potential as a bone graft substitute.
Total hip and knee arthroplasty surgery has revolutionised the management of patients with arthritis. The musculoskeletal and cardiopulmonary complications of such surgery are well recognised, however hepatic complications are rare. Elevated liver function tests in the early post operative period were noted in a cohort of patients undergoing elective hip and knee arthroplasty. The aetiology and significance of this phenomenon is uncertain.
A prospective study of all patients undergoing elective total hip and knee arthroplasty in one hospital by the senior author over a four year period was undertaken. All patients (over 300) had liver function tests (LFT’s), renal profile and haematological indices recorded pre operatively, one day, one week and six weeks post operatively. A standardised anaesthetic and post operative regime was followed.
Significant elevation of the liver enzymes, ALT (from 59 to 120), AST (from 47 to 81) and GGT (from 39 to 50) was noted after one week. These values returned to normal after six weeks. The bilirubin levels were also raised at one day (from four to eight) and at one week (from four to ten). Alkaline phosphatase and globulin levels remained within normal parameters. There was a fall in albumin and total protein levels in the immediate post operative period.
In conclusion, many patients undergoing elective total hip and knee arthroplasty experience significant hepatic enzyme dysfunction in the early post operative period. This elevation of liver function tests returns to normal after six weeks. The significance of these findings including likely causes is discussed.
Hip and knee replacements are common and successful surgeries in orthopaedics. One of the known complications is fat embolism. Cemented implants used in arthroplasty allow good implant fixation and excellent long term results. However this has been associated with an increased incidence of fat embolism.
This experimental animal study compared the amount of fat embolism following three different surgeries in 30 Sprague Dawley rats. These surgeries simulated hip replacement procedures and included a control surgery, an un-cemented implant and a cemented implant. These animals were then sacrificed at 24 hours. All the lungs were fixed in formalin and then stained using Osmium Tetroxide. The amount of fat was then counted using a light microscope at 40x power.
Both the uncemented implant group (p < 0.001) and the cemented implant groups (p < 0.003) had significantly higher fat emboli from the surgical control group. There were also a significantly higher number of emboli (p < 0.05) in the cemented implant group compared to the uncemented implant group.
We conclude that fat embolism occurs in both the un-cemented and cemented hip replacement. The amount of emboli created by un-cemented hip replacement is less than the cemented hip replacement. The cement itself does not cause the complication of fat embolism. It is the high intramedullary pressure associated with the insertion of the implant, and the cementing process, that contributes to fat embolism. Devices or surgery that minimise this rise in pressure could reduce the amount of fat embolism.
Between 1995 and 2000, nine patients between the ages of 12 and 15 years were treated for very large osteochondral fractures of the lateral femoral condyle with internal fixation of the displaced osteochondral fragment with bioabsorbable pins. Initial healing in these patients has been assessed with either follow up arthroscopy or MRI scanning. Early results suggested very good healing of the detached fragments.
The aim of this study was to review these patients at greater than five years follow up to assess how the healed articular cartilage has survived and performed. Eight of the nine patients were able to be followed up for clinical assessment, IKDC rating, Noyes Cincinnati Knee rating, radiologic and MRI assessment. Under the IKDC Knee Scoring system, five patients scored a final grade of A, two patients scored a grade of B and one patient scored C. Under the Noyes Cincinnati Knee Scoring system, three of the eight patients scored excellent, two scored good and three had a final rating of fair. There were no poor results.
X-rays, including weight bearing views, were assessed for evidence of lateral compartment degeneration. Six patients had normal knee x-rays. Two patients had subchondral bony irregularity in the lateral compartment with subtle lateral compartment narrowing.
We found that MRI scanning with specific cartilage sequences was an accurate way to assess healing and integrity of the articular cartilage at greater than 5 years. All patients had intact articular cartilage in the lateral compartment with no area of full thickness articular cartilage loss. Six of the eight patients had a small abnormal cleft-like signal corresponding to the likely posterior margin of the initial fracture fragment. Two patients had no cleft-like signal. The meniscii appeared normal in all patients. No evidence of pin tracts remained.
Our five-year follow up results suggest that the majority of the reattached articular cartilage does survive and these young, active patients’ knees have functioned well. The outcome in the longer term remains guarded. We recommend that internal fixation of these fragments with bioabsorbable pins, or other appropriate means of fixation, is a worthwhile procedure.
Articular cartilage has a limited regenerative capacity. Tissue engineering strategies adopting seeding and differentiation of individual chondrocytes on porous 3D scaffolds of clinically relevant size remains a considerable challenge. A well documented method to produce small samples of differentiated cartilage tissue in vitro is via micro-mass (pellet) culture, whereby, high concentrations of chondrocytes coalesce to form. a spherical tissue pellet. However, pellet culture techniques are not applied clinically as it is only possible to produce small amounts of tissue (1–2mm). The aims of this study were to develop a method for mass-production of pellets, and investigate whether an alternative “pellet seeding” approach using smart 3D scaffold design would allow large numbers of spherical pellets to be fixed in place.
Chondrocytes were isolated from bovine articular cartilage via enzymatic digestion. Freshly isolated and expanded (passage 2) chondrocytes were placed in 96-well plates with round- or v-shaped wells at a range of densities from 0.1, 0.25 and 0.5 million cells per pellet, and centrifuged at 500g for 2 min. In order to assess pellet forming conditions, cells were treated with or without 300 mg/mL fibronectin (FN, Sigma) to improve cell-cell adhesion. Wells were also coated with or without silicone (Sigmacote) to prevent cell adhesion to wells. Pellets were cultured in vitro for up to 14 days and were assessed at various timepoints for size, shape, cell number (DNA assay) and cell differentiation capacity (histology). A robotic Bioplotter device was used to produce porous, biodegradable scaffolds by plotting −250μm polymer (PEGT/PBT) fibres in a layer-by-layer process. Scaffolds with specific 3D pore architecture were produced to allow spherical pellets to be press-fit in each pore thereby fixing them in place throughout the scaffold.
Primary and expanded chondrocytes plated at a density of 0.25 million cell/pellet in v-shaped 96-well plates without both FN and silicone treatment produced pellets with consistently better spherical shape and total cell number (as determined via DNA). Under these conditions, cell (re)differentiation and cartilage extracellular matrix formation was observed via positive staining for safranin-O. Mass production of pellets was achieved by culturing multiple 96-well plates in parallel. FN treatment promoted cell-cell adhesion, but also cell adhesion to well plates, irrespective of silicone treatment, resulting in irregular shaped pellets, as did the use of round-bottom shaped wells.
Smart scaffold design and layer-by-layer fabrication process allowed direct control over the fibre spacing and pore size (1.0–1.25mm). Multiple layers of spherical pellets (1.25–1.5mm) were press-fit in place, thereby limiting the need for direct cell adhesion to the scaffold. Continued culture of constructs containing pellets resulted in consistent tissue formation throughout the scaffold.
In this study, we describe an alternative approach to the design and seeding of scaffolds for cartilage tissue engineering. Current limitations involved with adherence and de-differentiation of single cell populations were avoided by taking advantage of smart 3D scaffold design and pellet-seeding and culture techniques. Further optimisation and automation of the process is necessary, however, such strategies could be beneficial for future scaffold-based cell therapies for repairing articular cartilage defects.
I will discuss the reasons for and timing of retirement. Important issues include the funds necessary, inflation and your life expectancy. You need to consider your family, your health and your expected lifestyle. You will have been busy all your life and to fill this void you will need to extend old interests or develop new ones. The potential problems will be discussed in a light-hearted way.
Cannulated screw fixation is currently the treatment of choice for slipped capital femoral epiphyses (SCFE). A SCFE module of the Bonedoc simulator was created in order to test the ability of advanced trainees to place the screw in the correct position, and the practicality of using the simulator within the orthopaedic surgery training curriculum.
Bonedoc (University of Auckland) is a virtual reality simulator of image guided orthopaedic operations
Forty two advanced trainees operated on the same virtual SCFE during a training weekend. The trainees had 25 minutes to become familiar with the simulator and complete the operative case. The trainees performed all tasks relevant to the operation. At the operation’s conclusion the trainees self-assessed their performance. Subsequently the simulator provided surgically relevant objective feedback on aspects such as exact position of the screw, misplaced attempts and the number of x-rays. The results were analysed using SAS (SAS Institute, USA) in subgroups based on year on the scheme, as well as correlated within each operation.
There was no difference in the accuracy with which the virtual slipped capital femoral epiphysis was pinned by trainees in different years in the training programme. However, 26 of the 39 of the virtual screws were placed in the superior direction. There was no correlation between number of X-ray images taken and final accuracy of screw placement. The number of misplaced drill holes was correlated both with number of X-ray images taken (p< 0.01) and operative time (p< 0.01) but not with final accuracy of the screw. An increase in misplaced attempts was correlated with angulation errors in the anterior plane (p< 0.01). There was no correlation between the trainees’ self assessment and any of the measured variables.
The Bonedoc simulator provides a means to test trainees on technical aspects of a surgical procedure. It provides objective results, which can mimic real world outcomes. In addition, the ability to test all trainees on the same virtual operative case allows standardisation of assessment. All trainees completed the task to a similar level of accuracy, which may reflect the overall skill level in advanced trainees within the New Zealand. However, many trainees placed the screw in the superior portion of the femoral head, which is thought to increase the risk of avascular necrosis
The Salter osteotomy was first described in 1961 for treatment of acetabular dysplasia associated with congenital dislocation of the hip. The use of an innovative Korean modification, first reported by T Yoon in 2003, is outlined in this study. This modification has real advantages for both patient and surgeon.
A review of patients undergoing this surgery at the Starship Hospital between July 2003 and July 2006 by a single surgeon was carried out. All patients were independently assessed from the point of view of any complication of the procedure. All x-rays were reviewed independently of the operating surgeon, with the parameters being measured, including centre edge angle, acetabular index and percentage uncovering (migration index).
All ten osteotomies united with wires being removed at an average of four weeks post-osteotomy. All patients were asymptomatic at follow-up, the only complication recorded being a transient lateral cutaneous nerve palsy. Preoperatively, the centre edge angle was < 20 degrees in seven out of nine patients, indicating poor femoral head coverage. The mean centre edge angle was 11.8 degrees (range of 0.1– 21.1). Post operatively, the centre edge angle ranged from 14 to 38.9 degrees, with an average value of 25.6 degrees. The average improvement was 14.2 degrees. The acetabular index pre-operatively measured an average of 20.8 degrees (11.3–28.3 degrees) and improved an average of 8.3 degrees to a mean value post operatively of 12.5 degrees. The percentage uncovering also revealed improvement- the average uncovering was 34.9% pre-operatively (0–52%) and decreased to a mean of 18% (0–30%) post operatively.
This modification of the Salter osteotomy makes it easier to perform and provides better stability to the graft in the osteotomy site. It prevents the posterior and medial displacement of the distal innominate bone that has been observed in the standard Salter osteotomy. Image intensification is not required. A stable construct is created that can allow the patient to be free of a hip spica. The early results are excellent.
The efficiency of brace treatment for adolescent idiopathic scoliosis is correlated to how the brace has been worn. A smart orthosis was developed to maintain the interface pressure between the brace and the body within the prescribed range during daily activity. Six patients with scoliosis, with Cobb angles of 31 +/− 5 degrees, who were new brace candidates were recruited. They used the system for four weeks: two weeks with monitoring only and two weeks with an automatic feedback activated. The time that the pressure level was in target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. This work helps brace candidates wear their braces more effectively and receive the most benefit from the brace treatment. As a result, all subjects who participated in the study maintained their Cobb angles within + two degrees during the study period.
Brace correction based upon mechanical action requires appropriate interface pressure between the body and the brace. A smart orthosis was developed to record how much time (quantity) a brace was worn, how well (quality) it was used and how well the interface pressure was maintained to the prescribed level. Six subjects were recruited and they all were fitted with Boston style braces. Each subject wore the brace for 2 weeks without the force maintenance system activated to serve as the control period, and the remaining 2 weeks with the force maintenance system activated. During the automatic feedback mode, the pressure maintenance system was activated only during the daytime hours (8:00–22:00hrs) to avoid disturbing the patients during sleep. The subject could either return the system to us after 1 month or continue to use the system until the next clinic.
The time that the pressure level was in the target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. The average brace wear time for the study period was 72 +/− 15% (12.6hr/day) of the prescribed time (17.5 +/− 3.8 hours). The curve severity of all subjects on the following clinical visit was the same (within measurement error) as the first visit (32 +/− 5 vs 31 +/− 5 degrees). Compliance was not affected when wearing the monitor.
The smart orthosis was able to improve the efficiency of a conventional brace by maintaining the prescribed interface pressure automatically. This project helps brace candidates wear their braces more effectively and gets the most benefit from the brace treatment. As a result, all participating subjects maintained their Cobb angle within +/− 2 degrees during the study period.
Surgical resection of the persistently painful talocalcaneal tarsal coalition has not been shown to reliably relieve symptoms in patients with coalitions that are large and have associated hindfoot valgus and subtalar arthrosis. It has been recommended that these patients undergo triple arthrodesis, a procedure that is known to lead to premature arthrosis of the ankle joint. To avoid additional stress on this important joint, treatment of this patient group using calcaneal lengthening osteotomy (CLO), with or without resection of the coalition, has been performed at our institution for the last 15 years.
A retrospective review of all patients with talocalcaneal coalitions who had undergone CLO was performed. Clinical and radiographic records were reviewed. Demographic data, and pre- and post-operative pain and function were recorded. Pre- and post-operative radiographs and computed tomography (CT) scans were reviewed and measurements recorded. CT scans were used to calculate the degree of hindfoot valgus and the size of the coalition. Patients were invited to return for clinical examination and follow-up x-rays if two years had passed since their operation. They completed American foot and ankle hindfoot scores, VAS pain scores and were asked satisfaction questionnaires. Radiographic measurements were performed.
There were 13 patients who underwent 19 CLOs. Of these 13 patients, eight patients with 13 CLO’s returned for clinical examination and radiographs. Five patients had nine CLO’s to correct deformity without resection of a large middle facet talocalcaneal coalition with severe hindfoot deformity. All patients had restoration of normal foot shape with improvement in comfort and function. One patient had improvement in comfort and function following bilateral simultaneous coalition resection of cartilaginous coalition and CLO to correct significant hindfoot deformity. Two patients had improvement in pain and function in a foot that had residual pain and deformity following prior talocalcaneal coalition resection.
CLO, usually accompanied by a heel cord lengthening, is a useful operation both in the failed middle facet resection where there is persistent pain and deformity, and also in the very large coalition with associated deformity and/or arthrosis that is not appropriate for resection. It corrects the foot deformity, improves comfort and function, maintains motion in Chopart’s joints and therefore, unlike triple arthrodesis, avoids additional stresses in the ankle joint.
SPINE TANGO is the first International Spine Register. While it has now been fully operational for five years, no results of its collected data have been presented yet. The Swedish Spine Register has already shown that a National Spine Register can generate valid and meaningful data. Here we present data from the first three versions of SPINE TANGO.
From 2002 until 2006 about 6000 datasets were submitted by 25 hospitals worldwide. Descriptive analysis was performed for demographic, surgery, and follow-up data comparing all three versions of SPINE TANGO.
Over the course of its existence the SPINE TANGO data base showed a rise in median patient age from 52.3 years to 58.6 years and an increasing percentage of degenerative disease as main pathology from 60.1% to 71.4 %. Posterior decompression was the most frequent surgical measure. About one third of all patients had follow-ups. Rehabilitation was arranged more frequently, especially home-based and outpatient rehabilitation. The complication rate was decreasing below 10%.
The feasibility of data analysis from the International Spine Register SPINE TANGO could be demonstrated performing descriptive analysis with an evidence level III. In the near future, the meanwhile established SPINE TANGO version 3 with patient based data will make outcome
evaluation possible. This will enable us to present more comprehensive analyses of SPINE TANGO and to make the data base even more beneficial for the whole spine community. In parallel to the International Spine Register SPINE TANGO, a National Spine Register in New Zealand could be set up – comparable to NZOA’s National Joint Register.
Posterior spinal fusion is performed for a variety of lumbar spine conditions for relief of low back pain. Success relies on an effective fusion. Autograft is associated with donor site comorbidity and limited supply. Allograft has the potential for infection and has limited osteoinductive activity. Bone morphogenic proteins (BMPs) have been promoted for use in posterior spinal fusion despite considerable cost and limited evidence to their efficacy.
The aim of this study was to compare the clinical response, donor site morbidity and radiologic rates of fusion in patients undergoing posterior spinal fusion looking at the choice of bone graft or substitute. A retrospective review of 141 patients undergoing instrumented posterior lumbar spinal fusion by a single surgeon for degenerative disc disease, degenerative spondylolithesis or lytic spondylolithesis between 2000 and 2005 was undertaken. Patients were contacted and assessed for donor site morbidity and scored with the Oswestry Disability Index (ODI). Radiographs were taken and assessed by an independent blinded radiologist using the Ferguson score. Simple analysis was performed of these results to compare bone grafting techniques.
One hundred and forty-one patients were available for review. Fusions were performed for lytic spondylolithesis in 12.4%, degenerative spondylolithesis in 46% and for degenerative disc disease in 41.6% of patients. BMP-2 was used in 19.6%, allograft in 59.8% and iliac crest bone graft in 20.5% of patients. The BMP-2 and non BMP-2 groups were equally spread between the diagnosis and levels of surgery. The overall Ferguson score radiographic fusion rates for these patients was A in 67.9%, B in 17.9% and C in 11.9%. The BMP-2 group patients scored 76.9% (A group) and 23.1% (B group). The non-BMP-2 group scored 57.1% (A group), 23.8% (B group) and 19.1% (C group). The Oswestry Disability Index for patients with BMP-2 improved from 49.7% to 19%, whereas with no BMP-2 improved from 50.0% to 20.9%. Donor site morbidity was not identified as a problem in patients who had an autograft procedure.
Over the course of several years a single spinal surgeon’s posterior lumbar spinal fusion practice has evolved as a variety of bone grafting techniques have been trialled in an effort to increase the rate of bony fusion. There was no obvious difference in Oswestry Disability Index score but there was a modest difference in the Ferguson radiologic fusion score for the BMP-2 group. Morbidity in the autograft group was not a problem. These results have confirmed the efficacy of both allograft and autograft in fusion.
Lumbar discectomy is now the operation of choice for lumbosacral radicular syndrome. Few studies of high quality have been performed on the post surgical management of these cases. The studies that have been reported compare one exercise regime to another.
The aim of this study was to compare long term outcomes of usual surgical advice, involving no formal post-surgical rehabilitation, with a non-aggravating six month gym rehabilitation programme post lumbar discectomy. This study is a prospective randomised controlled trial using a cohort followed for three years.
The patients were computer randomised into two groups. Group A, the control group followed usual surgical advice which was to resume normal activity as soon as pain allowed. Group B, undertook the gym rehabilitation programme. Inclusion criteria were: age 17 to 65 years, good health and no major medical problems. The surgical level had to be L3, L4, or L5. Patients were excluded if they had central neurological disorders, communication difficulties, any condition making gym-based exercises unsafe, or if the surgery was indicated for spinal infection, tumour or inflammatory disease. Patients were followed for a three year period using validated outcome measures (Roland-Morris Questionnaire and Oswestry Low Back Pain Index) and an annual Quality of Life (QoL) questionnaire. The annual questionnaire reported information on number of GP visits, other therapist visits, medication levels and time off work.
Ninety three participants were randomised; Control n=46 and trial n=47. Eighty nine participants completed the study. Randomisation achieved a balance of confounding factors, with the exception of work heaviness, where there were a greater number of participants in the very heavy and heavy categories in the trial group (P<
0.01). Functional outcome measures did not achieve statistical difference over the three year period. Other studies have shown these measures to be reliable for short term follow up but their reliability diminishes with time (
The results reveal an advantage in terms of episodes off work and GP visits for participants in Group B who completed the programme. Time off work is a significant consideration for funding providers. These results suggest that surgeons should consider referral of discectomy patients to appropriate post-surgical rehabilitation programmes.
Currently available calcium silicate based ceramics pseudowollostonite (CaSiO3) ceramics are regarded as a potential bioactive material for bone tissue regeneration due to their osseointegration properties. A drawback of CaSiO3 ceramics is that they possess high dissolution rate, leading to a high pH value in the surrounding environment thereby affecting the biological activity of bone cells. We hypothesize that chemical modification of CaSiO3 ceramics will improve their physical and biological properties. The coordinated activities of osteoblasts (OB) and osteoclasts (OC) are critical for proper bone remodelling. Moreover, growing evidence indicate that vascular endothelial cells are involved in bone development and remodelling.
Present study aims at Chemically modifying CaSiO3 by incorporating zinc (Zn) and titanium (Ti) into their structure to develop novel materials Hardystonite (HT, Ca2ZnSi2O7) and Sphene (CaTiSiO5), respectively and to determine their effect on bone cells OB & OC and on endothelial cells.
It is well known that cell behaviour in a culture system is influenced by the physiochemical characteristics of the substrate. Human bone derived cells (HBDC) cultured on HT and Sphene supported the HBDC attachment (cells exhibited well defined cytoskeletal structure) showed characteristic features of cellular proliferation and differentiation. In addition, Zn and Ti incorporation into CaSiO3 supported the formation of mature, active and functional OC. Moreover, the modified bio-materials were found to be conducive to Human micro-vascular dermal endothelial cell growth. Our results suggest that HT and Sphene possessed an improved physical characteristics and enhanced biological activities of bone cells (OB & OC) and endothelial cells thus rendering it a potential material for bone tissue regeneration and coatings onto commonly used orthopaedic and dental implants.
Interactions between cells and polymers are mediated by proteins, which are either secreted by cells and immobilized on the biomaterial surface, or absorbed from the medium. Poly (lactic acid) (PLA) is widely used in tissue engineering as a scaffold material, however anchorage-dependent cells such as osteoblasts do not attach, grow, and differentiate well on a hydrophobic surface. In this study, a hydrophilic polymer-poly (ethylene glycol) (PEG) was used to develop diblock polymers, Methoxy-terminated poly (ethylene glycol)-Poly (lactic acid) (MPEG-PLA) to investigate cell-biomaterial interactions. Osteoblasts were cultured on different composition of PEG-PLA films in serum free or serum condition. Lactate dehydrogense (LDH) assay was used to assess the cytotoxicity of the copolymers and cell attachment and proliferation on the polymer surfaces; furthermore cell morphology was visualized by Crystal Violet stain.
The results showed that MPEG-PLA films induced early osteoblast attachment in serum free condition and the higher content of PEG in the MPEG-PLA films the more cell attachment was noticed. No significant difference of cell attachment was observed on MPEG-PLA films between serum free and 10% serum culture condition. Crystal Violet stain demonstrated the same trend in the cell-spreading characteristics on the polymer surface.
In conclusion MPEG-PLA copolymer can enhance osteoblast attachment under serum-free condition, which implies a potential application in cell delivery therapy due to the restriction in animal products for human therapeutically goods.
Large and retracted rotator cuff tendon tears fail to repair, or re-tear following surgical intervention. This study attempted to develop novel tissue engineering approaches using tenocytes-seeded bioscaffolds for tendon reconstruction of massive rotator cuff tendon defect in rabbits. Porcine small intestine submucosa (Restore™) and type I/III collagen bioscaffold (ACI-MaixTM) were chosen as bioscaffold carriers for autologous tenocytes. Biological characterization of autologous tenocytes was conducted prior to the implantation. The tenocyte-seeded bioscaffolds were implanted as interposition grafts to reconstruct massive rotator cuff tendon defects in rabbits. In situ re-implantation of the autologous rotator cuff tendon, excised during defect creation served as a positive control. Histological outcomes were analysed and semi-quantitatively graded at four and eight weeks after surgery.
The results demonstrate that at four weeks both tenocyte-seeded bioscaffolds display inflammatory reaction similar to bioscaffold-only cuff reconstruction and the histological grading were inferior to control repair. However, at eight weeks inflammatory reaction of both tenocyte-seeded bioscaffolds were dramatically reduced as compared to bioscaffold alone. In addition, bioscaf-folds seeded with tenocytes generated similar histological appearance to that of the positive control.
The implantation of autologous tenocytes on collagen-based bioscaffold offers improved rotator cuff tendon healing and remodelling compared to the implantation of bioscaffold alone.
Sutures from intraosseous anchors are used to secure soft tissue down onto bone during healing. Increasingly anchors are made from absorbable materials. Poly lactide carbonate (PLC - poly lactide with calcium carbonate) is an absorbable formulation with osteoconductive properties that should enhance both tissue healing and its own replacement by bone over time. An animal model of soft-tissue-to-bone healing was used to assess the efficacy of PLC Bioraptor™ anchors in comparison to anchors of non-osteoconductive poly lactide (PLLA).
Forty-seven ewes were used in two groups of PLC or PLLA anchors, surviving to either four or 12 weeks. The patellar tendon was pared off the tibia, the footprint decorticated then the tendon re-attached. An external fixator protected the tendon from load bearing for three weeks. At post mortem the patella/patellar tendon/tibia complex was either prepared for histological examination or stored deep frozen for later measurement of peak load at failure.
Non-operated specimens failed within the tendon mid substance; the failure site of healing specimens was dependent on their strength, with the weakest through interpositional granulation tissue, stronger specimens through fibres at various distances from the bone and the strongest, by partial bone avulsion.
Active healing of the enthesis consisted of merging regions of
a) re-established cortical bone plate; b) advancing mineralization of new, oriented collagen; c) dense, cellular collagen parallel to the tendon axis. Thin new bone was present around both PLLA and PLC anchors.
Healing tissues held by PLC suture anchors, were significantly stronger by 12 weeks than those held by PLLA anchors, possibly due to the calcium carbonate in the PLC anchor. However, the macroscopic and microscopic appearances of the healing tissues seemed little different between the two groups. This study indicates that PLC is a suitable replacement for PLLA in the fabrication of suture anchors. As well as its ability to produce stronger healing tissues, PLC has a shorter longevity in vivo and longer term is replaced by bone.
Synthetic biodegradable polymers have been utilized increasingly in pharmaceutical, medical and biomedical engineering. Control of the interaction of living cells and biomaterials surfaces is one of the major goals in the design and development of new polymeric biomaterials in tissue engineering.
In this study, a novel amphiphilic tri-block copolymer, methoxy-terminated poly (ethylene glycol) (MPEG) – polyL-lactide (PLLA) – polylysine (PLL) was synthesized. Various molecular compositions of tri-block copolymers were prepared via optimising the parameters and characterized through Nuclear Magnetic Resonance and Gel Permeation Chromatography. The tri-block copolymer was then mixed with high molecular weight PLLA to form a flat film. The surface properties measured by X-ray Photoelectron Spectroscopy and Atomic Force Microscopy demonstrated high content of the PLL on the surface of PLLA film, which indicated self-segregation of MPEG-b-PLLA-b-PLL on PLLA surface. No cytotoxicity was detected in triblock copolymers, and compared to pure PLLA and diblock copolymers, the triblock copolymers were much more effective for cell adhesion and proliferation. It was noted that the hydrophilic chain of PEG and PLL stretched out and formed an outer layer, especially under the aqueous environment, which resulted in enhanced cell attachment and proliferation. The self-segregation behaviour of MPEG-b-PLLA-b-PLL triblock copolymer shows a potential application in scaffold preparation of tissue engineering.
CaSiO3 has been used a potential bioactive material for bone regeneration. A drawback of the CaSiO3 ceramics is that they possess high dissolution rate of Ca ions leading to a high pH value environment [1], which can disadvantage cell growth. Zn can enhance osteoconductivity of CaP ceramics and stimulate bone formation [2]. The aims of this study are:
In situ preparation and optimization of Zn-CaSiO3 ceramics by the evaluating of physical and chemical properties, osteoblast and osteoclast behavior; Sol-gel coating the optimized hardystonite (HT, Ca2ZnSi2O7) on Ti-6Al-4V.
Zn-CaSiO3 ceramics containing zero, ten, 20 and 50-mol% of Zn were sintered at 1260 °C. The dissolution and apatite formation ability were evaluated by soaking in simulated body fluids. Attachment, proliferation and differentiation of human primary bone-derived cells (HBDC) on ceramic disks were evaluated. Human monocytes isolated from buffy coats were differentiated into mature and functional osteoclast (OC) by culturing them for 21 days on ceramic disks. Then, the optimized HT (50%Zn-CaSiO3) coating on Ti-6Al-4V was prepared by sol-gel spinning method.
The incorporation of Zn in CaSiO3 resulted in part of new phase formation (HT) formation in Zn-Ca-Si ceramics. When adding 50 mol% of Zn, only pure HT phase existed.
The incorporation of Zn in CaSiO3 decreased the dissolution and pure 50 mol% of Zn (HT ceramics) resulted in the lowest dissolution.
Zn-CaSiO3 ceramics with different Zn contents supported HBDC attachment. With the increase of Zn contents, HBDC proliferation and differentiation improved. The surface roughness of Sol-gel HT coating is about 0.49 μm. The thickness of coating is about 1 μm. HT coating has a similar dissolution kinetics and stability with hydroxyapatite coating.
Zn decreases the dissolution in Zn-Ca-Si ceramics and enhances HBDC proliferation and differentiation. The optimized HT ceramics (50mol% Zn) support OC resorption and can be used for a stable biomedical coating application.
Spinal fusion surgery is a common procedure for the treatment of various spinal diseases. Several growth factors, including bone morphogenic protein-2 (BMP-2) and osteogenic protein-1 (OP-1) have been used in spinal fusion for the induction of bone formation. But complications have been reported due to the lack of suitable carrier. Here we hypothesis that Insoluble Bone Gelatin (ISBG) may be a good carrier for OP-1 in the induction of bone formation during spinal fusion. The aim of this study is to examine the efficacy of osteoconductive carrier, ISBG, for OP-1 in rabbit lumbar inter-transverse process fusion model.
Adult New Zealand White rabbits (n=32) underwent bilateral lumbar intertransverse process fusion at L5-L6. The animals were divided into four groups based on the materials implanted:
Autograft group, ISBG group, OP-1 group and ISBG+OP-1 group.
Spinal fusion masses were evaluated by manual palpation, biomechanical testing, radiographic examination, micro-CT Scanning, and histological analysis six weeks after surgery.
ISBG+OP-1 group demonstrated significantly higher fusion rates (7/7) than autograft (3/7), ISBG (2/8), and OP-1 groups (2/7) (P< 0.05) based on manual palpation. In biomechanical testing, given the same moment, the fusion masses of ISBG+OP-1 group had less range of motions than those of other groups (P< 0.05) in main direction motion. Radiographic examination and micro-CT demonstrated that continuous trabecular pattern within intertransverse process area in ISBG+OP-1 group than other groups, and radiographic scores and bone volume base on micro-CT were also higher than other groups. Mature new bone formation was observed covering the surface of transverse processes in all four groups in histological findings. Continuous trabeculae connected two transverse processes and endochondral bone formation was observed attached the surface of ISBG in ISBG+OP-1 group. However, in other three groups, obvious gaps were noted in fusion masses and fibrous tissue was filled in these gaps.
In conclusion, OP-1 carried by ISBG results in more effective spinal fusion in posterolateral lumbar transverse fusion in rabbit model than autograft, ISBG or OP-1 alone.
Regenerative medicine techniques are currently being investigated to replace damaged cartilage. Critical to the success of these techniques is the ability to expand the initial population of cells while minimising de-differentiation to allow for hyaline cartilage to form. Three-dimensional culture systems have been shown to enhance the differentiation of chondrocytes in comparison to two-dimensional culture systems. Additionally, bioreactor expansion on microcarriers can provide mechanical stimulation and reduce the amount of cellular manipulation during expansion. The aim of this study was to characterise the expansion of human chondrocytes on microcarriers and to determine their potential to form cartilaginous tissue in vitro.
High-grade human articular cartilage was obtained from leg amputations with ethics approval. Chondrocytes were isolated by collagenase digestion and expanded in either monolayers (104 cells/cm2) or on CultiSpher-G microcarriers (104 cells/mg) for three weeks. Following expansion, monolayer cells were passaged and cells on microcarriers were either left intact or the cells were released with trypsin/EDTA. Pellets from these three groups were formed and cultured for three weeks to establish the chondrogenic differentiation potential of monolayer-expanded and microcarrier-expanded chondrocytes. Cell viability, proliferation, glycosaminoglycan (GAG) accumulation, and collagen synthesis were assessed. Histology and immunohistochemistry were also performed.
Human chondrocytes remained viable and expanded on microcarriers 10.2±2.6 fold in three weeks. GAG content significantly increased with time, with the majority of GAG found in the medium. Collagen production per nanogram DNA increased marginally during expansion. Histology revealed that chondrocytes were randomly distributed on microcarrier surfaces yet most pores remained cell free. Critically, human chondrocytes expanded on microcarriers maintained their ability to redifferentiate in pellet culture, as demonstrated by Safranin-O and collagen II staining. These data confirm the feasibility of microcarriers for passage-free cultivation of human articular chondrocytes. However, cell expansion needs to be improved, perhaps through growth factor supplementation, for clinical utility. Recent data indicate that cell-laden microcarriers can be used to seed fresh microcarriers, thereby increasing the expansion factor while minimising enzymatic passage.
Parathyroid hormone (PTH) and derivatives such as teriparatide (PTH (1–34)) have gained major attention in recent years in treatment of osteoporosis due to their anabolic action on the bone remodelling cycle. These drugs are currently the only available agents being classified as sole anabolic. Interestingly, action of these agents strongly depends on the way they are administered. While these drugs act catabolically when given continuously, they act anabolically when administered in a pulsatile way. Several hypotheses have been proposed to explain this behaviour. However, so far no agreement as regards detailed underlying biochemical regulation has been made. Parallel to intense experimental research to resolve this problem a few mathematical models have been proposed dealing with this subject. In this paper we propose a novel underlying mechanism for anabolic action of PTH based on mathematical modelling of bone cell population dynamics. Using this model allows us to investigate various hypotheses put forward by bone biologists. Additionally, comparison with other theoretical models proposed in the literature will be made.
Osteoclast Associated Receptor (OSCAR) is a novel member of leucocyte receptor complex (LCR)-encoded family expressed by pre-osteoclasts and mature osteoclasts (OC). Blocking of OSCAR binding to its putative ligand has been shown to inhibit osteoclast formation. To date there is no data available regarding the expression of OSCAR in tissues associated with osteolysis and the objective of this study is to determine if OSCAR is expressed adjacent to focal bone osteolysis near failed implants. A total of 22 samples (10 Peri-implant tissue and 12 OA) were studied. OSCAR antibodies were a gift from R& D Systems Inc. (Minneapolis, MN, USA). The tissues were analysed semi-qualitatively using semi-quantitative scoring (SQA) independently by two observers. Non-parametric Mann Whitney-U test was used to test statistical significance. Dual labelling for OSCAR and CD68 expression was also carried out. Strong expression of OSCAR was seen in the majority of multinucleated cells in peri-implant tissues while OA tissues showed very low levels of OSCAR expression. Dual labelling studies revealed that the cells expressing OSCAR also expressed CD68. There was a significant difference in the expression of OSCAR between peri-implant tissue and OA synovial tissue (p< 0.003). This study shows that OSCAR is expressed at high levels by the numerous CD68 multinucleated cells present is these tissues in peri-implant tissues. These findings and recent reports on the role OSCAR may play in OC formation indicate that OSCAR could be an important mediator of peri-implant osteolysis
Elastic energy-storing tendons including the equine superficial digital flexor tendon (SDFT) and human Achilles tendon significantly increase locomotor efficiency, but suffer high injury rates and experience increased core temperatures during exercise. Tenocytes are linked by gap junctions (GJ) comprised of connexin (Cx) proteins that mediate intercellular communication and are necessary for strain-induced collagen synthesis. The effects of hyperthermia on gap junction intercellular communication (GJIC) are unknown. We investigated the hypothesis that there is a down regulation in GJIC and Cx protein by tenocytes in response to hyperthermic episodes similar to those experienced in the SDFT of galloping horses.
Monolayers of equine SDFT-derived cells were heated to 45°C for 10 minutes. GJIC, Cx43 and Cx32 protein expression and cell viability were measured by fluorescence recovery after photobleaching (FRAP) and immunofluorescent labelling respectively.
There was a marked reduction in GJIC (p=< 0.0001) compared with controls (37oC) at 30min and 1h post-heating, with significant recovery by 2h (p=< 0.0001). The number of Cx43 plaques/cell also decreased significantly at 30mins (p=< 0.05), 1h (p=< 0.0001) and 2h (p=< 0.0001). There was however a 3-fold increase in the number of Cx32 plaques/cell at 1h (p=< 0.0001) that returned to normal by 2h. There was little change in cell viability up to 2h, however by 24h post-heating there was an 80% decrease in cell number indicating significant levels of cell death (p=< 0.0001).
Reductions in GJIC following exercise-induced hyperthermia may inhibit tenocyte collagen synthesis. Connexin isotypes may differentially modulate tenocyte collagen synthesis, therefore the dissimilar alterations in Cx43 and Cx32 following heating could have functional importance. The return of GJIC a few hours post-heating might facilitate spread of apoptotic death signals, killing neighbouring cells which would have otherwise escaped death. Understanding the responses of GJ to increased temperature, and the effects of this on viability and collagen synthetic capacity is likely to increase our knowledge of how exercise-induced SDFT core degeneration accumulates.
Evidence is accumulating for the role of bone in the pathogenesis of osteoarthritis (OA). Previous studies have shown a generalised increase in bone mass and hypo-mineralisation in OA patients. However, the molecular and cellular mechanisms involved in the increased bone mass and matrix compositional profiles in OA, at distal skeletal sites to the articular cartilage, have not yet been well defined. This study examined whether gene expression of bone anabolic factors, trabecular bone architecture and matrix mineralisation are altered in human OA and non-OA hipbone. Intertrochanteric (IT) trabecular bone samples were obtained from 15 primary hip OA patients (mean age 65 [48–85] years) and 13 closely age- and gender-matched autopsy controls (mean age 63 [44–83] years). Semi-quantitative RT-PCR analysis revealed elevated mRNA expression levels of alkaline phosphatase (p < 0.002), osteocalcin (p < 0.0001), osteopontin (p < 0.05), collagen type-I α chains COL1A1 (p < 0.0001) and COL1A2 (p < 0.002), in OA bone compared to control, suggesting possible increases in osteoblastic biosynthetic activity and/or bone turnover at the IT region in OA. Interestingly, the ratio of COL1A1:COL1A2 mRNA was almost 2-fold greater in OA bone compared to control (p < 0.001), suggesting the potential presence of collagen type-I homotrimer at the distal site that may associate with hypomineralisation in OA individuals. Using a quantitative backscatter electron imaging technique, mineralisation profiles of IT trabecular bone indicated decreased mineralisation in the OA group compared to the control group (24.2 weight percent calcium [wt%Ca] versus 25.3 wt%Ca). Bone histomorphometric analysis found OA IT bone had increased surface density of bone and decreased trabecular separation compared to control bone. Taken together with a reported increase in diffuse microdamage in OA IT bone (Fazzalari et al. Bone 31:697–702, 2002), possibly due to hypomineralisation, these results are consistent with the altered bone material properties found in OA individuals. The finding of differential gene expression, altered mineralisation and architectural changes in OA bone, at a skeletal site distal to the active site of joint degeneration, supports the concept of systemic involvement of bone in the pathogenesis of OA.
Fracture healing continues to pose challenges for researchers and clinicians in the field of trauma and orthopaedic surgery. The future treatment strategies for fracture healing will most likely focus on the use of biologic and biochemical methods in combination with established fixation and mechanical methods. In this study, heparanase (HPSE), a mammalian endo-glycuronidase that promotes angiogenesis through cleavage of the extra cellular matrix (ECM)-heparan sulphate and mobilization of ECM resident growth factors, was investigated for its osteoblasts-stimulating effect.
Osteoblast cells, originated from osteoporotic and healthy human subjects who underwent total knee replacement, were cultured and exposed to HPSE at a series of final concentrations of 1, 3, and 6μg/mL. The cell density, proliferation, alkaline phosphatase (ALP) production and specific activity, and expression of osteogenic genes were examined.
A marked stimulating effect of HPSE in cell density and proliferation was observed in the osteoblastic cultures from both osteoporotic and healthy subjects. The ALP level and its specific activity, a classical osteoblastic marker, were also increased at the presence of HPSE in a dose-dependant manner. The expression of osteogenic pathway genes, particularly bone morphogenic proteins (BMPs), transcription factors SMDs, vascular endothelial growth factor and tissue inhibitor of metallopeptidase (TIMP) were up- or down-regulated, which correlated with the doses of HPSE.
This study is the first to show that HPSE increases cell proliferation and stimulates differentiation in human osteoblasts suggesting that the potential of HPSE as a new biofactor for the treatment of fractures. Further research on HPSE in co-culture of osteoblasts and osteoclasts is under investigation in our laboratory.
Vacuolar adenosine triphosphatase (V-ATPase) proton pumps play an essential role in the acidification of the bone matrix during osteoclast-mediated bone resorption. Recently, mice lacking the V-ATPase d2 subunit have been shown to be osteopetrotic due to defective osteoclasts (Lee et al., Nature Med, 2006). Here, to investigate the transcriptional regulation of the d2 gene during RANKL-induced osteoclastogenesis, we have cloned and characterized its promoter region. By semi-quantitative RT-PCR, expression of d2 and NFATc1 was found to be strongly up-regulated by RANKL but not by other pro-osteoclastic factors including TNF, LPS and M-CSF. Bioinformatic analysis of the cloned 3 kb d2 promoter region revealed several candidate transcription factor binding sites including NFATc1, a key transcription factor for osteoclastogenesis.
To explore the influence of RANKL on d2 transcription, we generated a series of d2 promoter constructs using the pGL-3 reporter plasmid. Using luciferase assays, the d2 promoter was found to be induced by RANKL stimulation. Chromatin immunoprecipitation (ChIP) assays demonstrate that NFATc1 forms a complex with the d2 promoter. Using EMSA assays, we have defined a specific NFATc1 biding site between nucleotide − 555 to −561 upstream from the translation start site of d2 gene. Furthermore, targeted mutagenesis of the putative NFAT transcription binding site was found to significantly reduce the luciferase activity as induced by NFATc1 over expression. Addition of the NFAT inhibitor cyclosporin A was found to blunt the mRNA expression of d2 induced by RANKL in RAW264.7 cells.
We propose that NFATc1 is an important regulator of d2 transcription during RANKL-induced osteoclastogenesis.
To regenerate the complex tissue such as bone-cartilage construct using tissue engineering approaches, controllable differentiation of mesenchymal stem cells (BMSCs) into chondrogenic and osteogenic lineages is crucially important. Although bilayered scaffolds have been investigated in vitro and in vivo, no culture system is available to test BMSCs differentiation into bone and cartilage simultaneously in bilayered scaffolds. This study investigated a defined culture media, which supported osteoblast and chondrocyte differentiation depending on growth factors implemented in biomaterials. In 2-dimensional culture, BMSCs differentiated to chondrocytes when transforming growth factor-beta 3 (TGF-β3) was added to the defined media, whereas osteogenic differentiation was induced by adding bone morphogenetic protein 7 (BMP-7). BMSC differentiation to osteogenic and chondrogenic lineages was further strengthen in 3-dimensional culture. Proteoglycan formation, type II collagen, and aggrecan were upregulated in the defined media when BMSCs were mixed with fibrin gel impregnated with TGF-β3. Mineralization and the expression of osteogenic markers such as alkaline phosphatase, osteopontin, and osteoclacin were noticeable when BMSCs cultured in hydroxyapatite-tricalcium phosphate (HA/TCP) scaffolds coated with BMP-7.
This study generated and tested a growth media, which could induce osteogenic and chondrogenic differentiation of BMSCs in one culture system. These results will help the development of tissue substitutes for multi-complexed tissues such as subchondral replacement.
Calcitonin has been recently shown to have a direct protective effect on articular cartilage against joint degenerative disease. It has been proposed that calcitonin might act through the calcitonin receptor (CTR) to activate the cyclic AMP pathway and protect type II collagen degradation. In this study, we examined the presence of the CTR in human articular cartilage and chondrocytes and investigated the potential pharmacological effects and transduction pathway of salmon calcitonin in human chondrocytes.
Five human articular cartilage samples were examined for the expression of the CTR by polymerase chain reaction (PCR), immunostaining and Western blotting. Cyclic AMP levels in human chondrocyte stimulated with salmon calcitonin were measured by ELISA. The effect of salmon calcitonin on the gene expression profiles, including aggrecan, type II collagen, matrix metalloproteinase (MMP)-1, MMP-3 and MMP-13, of human chondrocytes was also examined by Real-time PCR.
It was shown that CTR was not detectable in human cartilage and chondrocytes. The cAMP level in human chondrocytes in vitro was significantly increased by forskolin (100μM) by > 10 fold (P< 0.001), but was not induced by salmon calcitonin (10^-7M, 10^-8M, 10^-9M). Real-time PCR demonstrated that salmon calcitonin tended to reduce the gene expression of MMPs, yet without statistical significance. In contrast to previous reports, our data showed that human cartilage and chondrocytes do not express calcitonin receptors. There was no direct effect of salmon calcitonin on human chondrocytes.
The result suggests that the chondroprotective effect of calcitonin observed in vivo may be indirect via its effect on subchondral bone resorptive activity.
In both physiological and pathological processes, periosteum plays a determinant role in both bone formation and fracture healing. However, no specific reports are available so far focusing on the detailed structural and major cellular differences between the periostea covering different bone surface areas in relation to ageing. The aim of this study is to compare the structural and cellular differences in diaphyseal and epiphyseal periostea in different-aged rats using histological and immunohistochemical methods.
Four female Lewis rats from each group of juvenile (7-week old), mature (7-month old) and aged groups (2-year old) were sacrificed and the right femur of each rat was retrieved, fixed, decalcified and embedded. 5μm thick serial sagittal sections were cut and stained with Hematoxylin and Eosin, Stro-1 (stem cell marker), F4/80 (macrophage marker), TRAP (osteoclast marker) and vWF (endothelial cell marker). 1mm length of middle diaphyseal and epiphyseal periosteum were selected for observation. The thickness, total cell number and positive cell number for each antibody in each periosteal area and different-aged groups were measured and compared. The results were subjected to ANOVA and SNK-q tests.
The results showed that the thickness and cell number in diaphyseal periosteum decreased with age (p< 0.001). In comparison with diaphyseal area, the thickness and cell number in epiphyseal periosteum were much higher (p< 0.001). There were no significant differences between the juvenile and aged groups in the thickness and cell number in cambial layer of epiphyseal periosteum (p> 0.05). However, the juvenile rats had more Stro1+, F4/80+ cells and blood vessels and few TRAP+ cells in different periosteal areas compared with other groups(p< 0.001). The aged rats showed much less Stro1+ cells, but more F4/80+,TRAP+ cells and blood vessels in the cambial layer of epiphyseal periosteum (p< 0.001).
In conclusion, the age-related structure and cell population in diaphyseal and epiphyseal periostea are different, especially in aged rats. The epiphyseal periosteum of aged rats seems more destructive than diaphyseal part and other age groups. Macrophages in the periosteum play a dual important role in osteogenesis and osteoclastogenesis.
Bone Tissue Engineering Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4059, Australia.
Osteophytes are the most remarkable and consistently distinct feature of osteoarthritis (OA). Their formation may be related to pluripotential cells in the periosteum responding to stimulus during OA. This study aimed to isolate stem cells from osteophyte tissues, and characterise their phenotype, proliferation and differentiation potential, and immuno-modulatory properties.
Osteophyte derived cells were isolated from five osteophyte tissue samples collected during knee replacement surgery. These cells were characterised by the expression of cell surface antigens, differentiation potential into mesenchymal lineages, growth kinetics and modulation of allo-immune responses.
Multipotential stem cells (MSCs) were identified from all osteophyte samples namely osteophyte derived MSCs (oMSCs). The surface antigen expression of oMSCs was consistent with that of mesenchymal stem cells, such as lacking the haematopoietic and common leukocyte markers (CD34, CD45) while expressing those related to adhesion (CD29, CD166, CD44) and stem cells (CD90, CD105, CD73). The longevity of oMSCs in culture was superior to that of bone marrow derived MSC (bMSCs), and they readily differentiated into tissues of the mesenchymal lineages. oMSCs also demonstrated the ability to suppress allogeneic T-cell proliferation, which was associated with the expression of tryptophan degrading enzyme indoleamine 2,3 dioxygenase (IDO).
Our results showed that osteophyte derived cells had similar properties to mesenchymal stem cells in the expression of antigen phenotype, differential potential and suppression of allo-immune response. Furthermore, when compared to bMSCs, oMSCs maintained a higher proliferative capacity, which may offer an alternative source for therapeutic stem cell based tissue regeneration.
Osteoclastic bone resorption is a highly dynamic process that requires the tight ordering of intracellular trafficking events in order to maintain the structural and functional polarization of the ruffled border and basolateral domains. Rab3 proteins are a subfamily of GTPases, known to mediate membrane transport in eukaryotic cells and play a role in exocytosis. Our recent data indicates that Rab3D modulates a post-TGN trafficking step that is required for osteoclastic bone resorption (1). Here, to identify down-stream regulatory molecules of Rab3D, we have performed a yeast two-hybrid screen. Amongst several candidate Rab3D-interacting proteins identified, Rab3D was found to associate with calmodulin, an established regulator of osteoclastic bone resorption. As an initial effort to better define the interaction between Rab3D and calmodulin, we generated several mutants of Rab3D which interfere with the GDP/GTP nucleotide exchange (Rab3DQ81L, Rab3DN135I) and/or membrane attachment of Rab3D (Rab3D-CXC). By in vivo bioluminescence resonance energy transfer (BRET) assay, Calmodulin was found to associate equivalently with wild type Rab3D as well as Rab3DN135I and Rab-3DCXC variants. Over expression of constitutively active Rab3D (Rab3DQ81L) enhanced this interaction suggesting that the active form of Rab3D (i.e. GTP-bound) might recruit additional effector molecules which further potentiate it’s binding to calmodulin. In an attempt to address the impact of calmodulin activity on Rab3D-calmodulin interaction and osteoclastic bone resorption, we performed complementary BRET and in vitro bone resorption assays in the presence of the calmodulin inhibitor, calmidazolium chloride. Interestingly, we show that suppression of calmodulin activity via calmidazolium chloride impairs the association of Rab3D with calmodulin, an affect that correlates with a disruption in osteoclastic bone resorption. We propose that the recruitment of calmodulin by Rab3D might be an important requirement for osteoclast-mediated bone resorption.
Bone Tissue Engineering Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
Adult mesenchymal stem cells (MSCs) are a topic of immense research interest in the field of tissue engineering. Since, depletion of multipotent cells has been implicated in degenerative joint diseases, cell based therapies have been proposed for tissue regeneration, especially for cartilage repair. The aim of the present study is to focus on the possibility of deriving and expanding multipotential MSCs from the heterogeneous bone marrow stromal samples of patients with osteoarthritis (OA) by characterising MSCs at the single cell level.
Single cell clonal cultures were established by limiting dilution of marrow stromal cells from three OA patients. A total of 14 clones with a wide variation in their cell doubling time were isolated. The clones were grouped into fast-growing and slow-growing clones. All except one of the fast-growing clones were tripotential. However the slow-growing clones showed limited differentiation potential and morphological changes associated with cellular senescence with extended duration in culture. Flow cytometric analysis did not depict any difference in the expression of the selected putative MSC cell surface markers CD29, CD44, CD90, CD105 and CD166 between fast-growing and slow-growing clones indicating a strong need to investigate for novel cell-surface markers. Further, proteomic analysis to understand the sub-cellular processes responsible for the existence of varying sub-populations identified 11 differentially expressed proteins. These proteins were reported to be associated with cellular organization, signal transduction, energy pathways and stress related proteins. Identification of signaling pathway proteins and cell cycle related proteins, such as calmodulin and caldesmon in the clonal populations, suggest that high-throughput proteomic technologies like two dimensional liquid chromatography (2D LC) coupled with mass spectrometry (MS) may facilitate the discovery of therapeutically useful biomarkers.
This study demonstrated the existence of a fast-growing multipotential MSC population from bone marrow samples of patients with OA. Therefore, despite a supposedly smaller stem cell compartment in these patients, we demonstrate here that they can still yield a potentially therapeutically useful source of syngeneic MSCs.
With the development and popularisation of minimally invasive surgical methods and implants for fracture fixation, it is increasingly important that available implants are pre-contoured to the specific anatomical location for which they are designed. Due to differences in the bone morphology it is impossible to design single implants that are universally applicable for the entire human population. A recent study on the fit of a distal periarticular medial tibia plate to Japanese bones supported the need for shape optimisation [1]. The present study aimed to quantify and optimise the fit of the same plate for an extended dataset of Japanese tibiae.
Forty-five 3D models of the outer bone contour of Japanese tibiae were used. The average age of the specimens was 67 years with an average height of 156 cm. All bone models were considered to be within a normal range without any bony pathology. An anatomical fit of the plate was defined with four criteria [1]. The current plate shape was optimised based on the quantitative results of the plate fitting. Two different optimised plate shapes were generated.
The current plate shape achieved an anatomical fit on 13% of tibias from the dataset. Plate 1 achieved an anatomical fit for 42% and Plate 2 a fit for 67% of the bone models. If either Plate 1 or Plate 2 is used, then the anatomical fit can be increased from 13% to 82% for the same dataset. For 12 (27%) of the 45 bones both modified plate shapes were fitting.
The results for the fit of the current plate shape are comparable to findings of a similar study on the anatomical fitting of proximal tibia plates [2]. The obtained results indicate that for the available dataset no further modification is warranted for the shaft region of the modified plates. Further optimization of the distal regions of Plate 1 and Plate 2 will be possible. This study shows that in order to achieve an anatomical fit of the plate to the medial Malleolus at least two different plate shapes will be required.
Percutaneous radiofrequency facet joint denervation (RFJD) has been used increasingly since being described by Shealy1 for the non-surgical treatment of chronic low back pain. Extensive literature exists on this technique with a number of randomised control studies suggesting efficacy against Placebo2,3. However, the efficacy and reliability of repeat RFJD for chronic back pain is unknown.
A prospective study was carried out on a consecutive series of 57 patients undergoing repeat lumbar RFJD between 2004 & 2006. 57 consecutive patients treated by the senior author (OLO) between April 2004–June 2006 were included in a prospective analysis using a visual analogue score (VAS) and the low back outcome score (LBOS).
All 57 participants completed a telephone questionnaire at follow up. There were no complications. At a median average follow up of 14 months overall, clinical outcomes demonstrated moderate improvement in the majority of patients with poor rating at LBOS decreasing from 54.3% pre- to 40.3% post-RFJD. The overall degree of satisfaction was 77.2%. The overall median duration of pain relief was 10 months.
Our study suggests that repeat RFJD appears to have reliable and satisfactory results when repeated with most patients reporting a high degree of satisfaction and with the clinical outcome similar to the initial procedure.
Cerebral palsy (CP) results from an injury to the immature brain; and it leads to progressive musculoskeletal (MS) impairment in most affected patients. Orthopaedic surgery involving muscle-tendon lengthening is a method for managing short muscles in CP patients. Knowledge of muscle length prior to surgery is beneficial to surgical success. However, using common assessment methods like 3D gait analysis or physical examination, accurate pre-surgery estimation of muscle lengths during walking is difficult.
Computer models of the lower limbs, which provide more insight into muscle functioning during walking, have become increasingly important within the research field of CP. MS models are commonly driven by joint kinematics from clinical gait analysis. The most often used MS model in CP related research is based on the geometry of an adult human man with muscles modelled as line segments. This approach might be reasonable for small muscles with well-defined paths; however, for long muscles with multiple attachment points and curved paths, a more realistic 3D muscle model is required.
The aim of this study is the development of a clinical assessment tool for CP patients by incorporating kinematic data from gait analysis into a 3D finite-element MS model of the lower limbs. Ethical approval has been obtained to develop subject-specific MS models of 12 children with CP and 12 control children (age 8 – 12 years) based on magnetic resonance images. Kinematic data from 3D gait analysis is used as input data to transform the bony structures. Soft-tissue muscle deformation is modelled according to a variant of free-form deformation called the Host-Mesh Fitting Technique. So far, MS models of the lower limbs of three control children and of one child with CP were developed. The resulting muscle length changes during walking agree reasonably well with published data. The proposed modelling approach together with the library of 24 MS models will enable us to develop a powerful tool to investigate gait of children with CP.
Adiponectin, a hormone secreted by adipocytes, regulates energy homeostasis and glucose and lipid metabolism. Plasma levels of adiponectin are negatively correlated with body fat mass. Adiponectin inhibits the formation and activity of osteoclasts and increases the proliferation and differentiation of osteoblasts in vitro. The aim of our study was to determine the bone phenotype of adiponectin knockout mice.
Male adiponectin-deficient (Ad-KO) and wild-type (WT) C57BL/6J mice were sacrificed at 8, 14 and 22 weeks of age. Body weights did not differ between Ad-KO and WT mice. We scanned the left proximal tibia using micro-CT at 5μm resolution and analysed bone microarchitecture by 3D analysis.
We found significant increases in trabecular bone volume (BV/TV) (15.9±1.63 vs. 12.2±0.72%, p=0.02) and trabecular number (3.20±0.18mm-1 vs. 2.32±0.12mm-1, p=0.0009) in 14-week old Ad-KO mice compared to controls. Similar differences between WT and Ad-KO were present in 8 and 22-week old animals but these did not reach statistical significance. Trabecular thickness was significantly greater (0.053±0.001mm vs. 0.048±0.002mm, p=0.04) in 22-week old Ad-KO mice compared to WT.
Ad-KO mice have increased number and volume of trabeculae at 14 weeks of age indicating that the net effect of adiponectin on bone accrual in vivo is inhibitory. These effects are age-dependent. Our data concur with the observations from epidemiological studies in humans that adiponectin negatively correlates with both fat mass and bone mass. Therefore, adiponectin may be a contributor to the link between fat and bone mass.
During certain motions, the disc is at risk of annular injury. Axial compression coupled with various combinations of excessive flexion, lateral bending or axial rotation has been shown to lead to disc injury. However, similar injuries have also been caused by repetitive activity at lower, more physiological ranges of motion. The primary objectives of this study were to determine the regions of largest shear strain experienced by disc tissues in six degrees of freedom (DOF), since shear is considered a likely tissue failure criterion, and to identify the physiological motions that may place the disc at greatest risk of injury.
A grid of wires was inserted into the mid-transverse plane of nine human lumbar discs that were subjected to each of six principal displacements and rotations. Stereo-radiographs were taken in each position and digitised for reconstruction of the 3D position of each grid intersection. Maximum shear strains (MSS) were calculated from relative grid-intersection displacements and normalised by the input displacement or rotation. Physiological MSS were calculated using the maximum reported physiological lumbar segmental motion for each DOF.
The largest MSS were found in the posterior, posterolateral and lateral regions of the disc. For the translation motions, lateral shear and compression produced the largest MSS (approx. 9%/mm). For the rotation motions, lateral bending had significantly larger MSS than all other tests (5.8±1.6 %/°, P< 0.001).
The physiological MSS was greatest for lateral bending, being significantly larger than all other motions (57.8±16.2%, P< 0.001). In addition, physiological MSS for flexion was also significantly larger than for all remaining motions (38.3±3.3%, P< 0.001).
This study has identified lateral bending and flexion as the lumbar segmental motions that may place the disc at greatest risk of injury. The exact failure criterion for intervertebral disc tissue is not known, and MSS was used because it is related to maximum and minimum principal strains, and it was shown that disc tears may be initiated by large interlamellar shear strains that dominate over radial and circumferential annular fibre strains. These results provide improved understanding of disc behaviours under loading and may also be of value validating finite element models.
Intramedullary reaming causes elevation in intramedullary pressure (IP) and extravasation of intramedullary contents into the venous blood system. This study was to evaluate the effect of an intramedullary suction system (ISS), recently developed in our laboratory, on the IP and fat extravasation in a sheep model.
Twelve skeletal mature sheep were assigned randomly to 2 experimental groups of 6 sheep: instrumentation and reamed intramedullary nailing without the ISS application and instrumentation and reamed intramedullary nailing with ISS application. During reaming, the IP was recorded at each step of the procedure. Haemo-dynamic parameters were monitored at pre-reaming, 10 min post-reaming, and 50 min post-reaming, including, mean arterial blood pressure (MABP), pulmonary artery pressure (PAP), pulmonary arterial CO2 (Paco2), heart rate (HR), and saturated oxygen (SaO2). Blood and lung tissue samples were collected for the examination of medullary fat intravasations.
Dramatic increases in IP were observed in non-ISS group at the six defined measuring times: before drilling, guide wire, reaming 8 mm (reamer size), 9 mm, reaming 10 mm, and reaming 11 mm. The IP during reaming was significantly lower in ISS group (guide wire, 15 mmHg; 8 mm, 13 mmHg; 9 mm, -1 mmHg; 10 mm, 3 mmHg; 11 mm, 16 mmHg) than in non-ISS group (guide wire, 28, 8 mm, 185 mmHg; 9 mm, 168 mmHg; 10 mm, 146 mmHg; 11 mm, 150 mmHg). These reductions were significant with the P values < 0.05 or 0.01. Paco2, was lower in ISS group than non-ISS group (32 and 40 mmHg, respectively), while SaO2 was higher in ISS group than non-ISS group (99 and 91 mmHg, respectively). Histological data revealed fat emboli in sheep lung tissue in non-ISS group. Total lipids in lung specimen was lower in ISS group (7.6 mg/g tissue) than in non-ISS group (13.6 mg/g, P=0.04).
We demonstrate the ISS in controlling the increase in IP occurring in long bone reaming. The ISS allows real time pressure recording and feedback to the operator. With this feedback, the operating surgeon is able to control the rate of forward reaming to prevent major increases in IP
Defects in annulus fibrosus induced by needle puncture can compromise mechanical integrity of the disc and lead to degeneration in animal models. This study examined the immediate and short-term mechanical and biological response to annulus injury through needle puncture using small and large gauge needles in a bovine organ culture system.
Bovine caudal intervertebral discs were harvested, assigned to one of two needle puncture groups (small = 25G, N=11; large = 14G, N=12) or an unpunctured control group (N=10), and cultured in organ culture for 6 days. After measuring initial heights, diameters, and wet weights, discs were placed in an organ culture chamber and incubated with constantly circulating media in standard culture conditions under a 0.2 MPa static load. Discs underwent a daily dynamic compression loading protocol for five days from 0.2 – 1 MPa at 1 Hz for one hour. Disc structure and function were assessed with measurements of dynamic modulus, creep, height loss, water content, proteoglycan loss to the culture medium, cell viability and histology.
Needle insertion caused a rapid decrease in dynamic modulus and increase in creep during one hour of loading, although no changes were detected in water content, disc height, or proteoglycan lost to the media. Cell viability was maintained except for localised cell death at the needle insertion site. An increase in cell number and possible remodelling response was seen in the insertion site in the nucleus pulposus.
Relatively minor disruption in the disc from needle puncture had immediate and progressive mechanical and biological consequences with important implications for the use of needle puncture in discography, and repair/regeneration techniques. Results also suggest diagnostic techniques sensitive to mechanical changes in the disc may be important for early detection of degenerative changes in response to annulus injury.
Biomechanical properties of the disc provide both flexibility and shock absorption. We hypothesised that frequency-dependent effects in shear and torsion deformations in which intrinsic viscoelasticity (solid phase) predominates would differ from compression and bending, in which fluid flow-mediated poroelasticity is also present.
Disc-vertebra-disc preparations (N=8) from human lumbar spines were subjected to each of three displacements and three rotations (6 degrees of freedom - DOF) at each of four frequencies (0.001, 0.01, 0.1, and 1 Hz) after equilibration overnight under a 0.4 MPa preload in a bath of PBS at 37C with protease inhibitors. The forces and torques were recorded along with the applied translation or rotation. The stiffness (force/displacement or torque/rotation) and the phase angle (between each force and displacement) were calculated for each degree of freedom from recorded data.
The stiffness significantly increased linearly with the log-frequency in most DOF (P< 0.001) apart for lateral bending and flexion/extension (P> 0.055). The increases over the four decades of frequency were 28%, 23% and 25% for antero-posterior (AP) shear, lateral shear and torsion respectively, and were 53%, 33% and 36% for compression, lateral bending and flexion.
The phase angle (a measure of energy absorption) significantly decreased overall with increasing frequency in all DOF (P< 0.005) apart for lateral bending. During AP and lateral shear, significant decreases in phase angle of 10% were found between 0.001 Hz compared to 0.01 Hz and 0.1 Hz (P< 0.026) with no differences found at 1 Hz. For torsion, the phase angle at 1 Hz was significantly lower by 40% compared to all slower frequencies (P< 0.001). During compression, a large significant drop in phase angle of 25%–35% occurred between 0.001 Hz and all other frequencies (P< 0.016). No significant post-hoc differences were found for flexion-extension (P> 0.057).
The dynamic effects (stiffness increase, and phase angle decrease with frequency) were consistently greater for deformation modes in which fluid flow effects are thought to be greater. Both the solid phase viscoelasticity and the fluid phase poroelasticity of the tissue appear to contribute to the disc stiffness and energy absorption, although these differences become more apparent at 1 Hz compared to the slower frequencies.
In recent years, plate osteosynthesis in metaphyseal and diaphyseal long bone fractures has been increasingly applied in a minimally invasive fashion. Several clinical studies describe a beneficial effect of the smaller additional soft tissue damage, resulting in satisfying fracture and soft tissue healing. However, is the surgical soft tissue damage really evidently smaller and the recovery faster?
A trauma model with severe, circumferential soft tissue damage to the distal right thigh and a distal multifragmentary (AO type C) femur fracture was carried out on 24 male sheep. After five days temporary external fixation, an internal fixator was placed either by a conventional open lateral approach or by minimally invasive technique. To assess the soft tissue damage and its recovery within the first 14 days, local compartment pressure monitoring as well as daily measurements of systemic markers (Creatin Kinase, CK and Lactate Dehydrogenase, LDH) in blood were performed. The local monitoring with a special probe (Neurovent PTO, Raumedic AG, Germany) within the quadriceps muscle allowed the measurement of compartment pressure (CP), as well as temperature.
The CK and LDH levels responded to the severe trauma with high peaks within the first 48 hours post trauma. After the internal fixator operations CK levels illustrate a significantly lower increase (p< 0.05) in the minimally invasive group compared to the open approach group in the first two days postoperatively. LDH levels show lower values for the minimally invasive group (p=0.06).
The values of CP present an initial increase after the trauma and then higher values (p=0.08) after the open plating operation. For the intracompartmental temperature no statistical differences were found, too (p=0.17).
These results, with reduced additional soft tissue damage and faster recovery in the minimally invasive approach group, reflect the clinical experience and expectations. However, while minimally invasive plate osteo-synthesis is certainly a desired option for fracture fixation, good surgical skills are required to insure that the reduced surgical trauma is in line with optimal fracture healing. The influence of the two different approaches on the bone healing per se, as well as the influence on soft tissue functionality, has yet to be demonstrated.
The anulus fibrosus of the human lumbar intervertebral disc has a complex, hierarchical structure comprised of collagens, proteoglycans and elastic fibres. Recent histological studies have suggested that the elastic fibre network may play an important functional role. In this study, it was hypothesised that elastic fibres enhance the mechanical integrity of the extracellular matrix transverse to the direction of the collagen fibres.
Using a combination of biochemically verified enzymatic treatments and biomechanical tests, it was demonstrated that degradation of elastic fibres resulted in a significant reduction in both the initial modulus and the ultimate modulus, and a significant increase in the extensibility, of radially oriented anulus fibrosus specimens. Separate treatments and mechanical tests were used to account for any changes attributable to non-specific degradation of glycosaminoglycans. Additionally, histological assessments provided a unique perspective on structural changes in the elastic fibre network in radially oriented specimens subjected to tensile deformations.
The results of this study demonstrate that elastic fibres play an important and unique role in the mechanical properties of the anulus fibrosus, and provide the basis for the development of improved material models to describe intervertebral disc mechanical behaviour.
Long term clinical follow-up of total hip arthroplasty (THA) has identified problems associated with cyst formation. Such cysts are formed as a result of expansile osteolysis, which starts on a small area of the skeleton and spreads into the bone away from the surface of the prosthesis. Since large areas of the prosthesis are still in immediate contact with the skeleton the prosthesis is not loose and the patients are usually without pain. However this form of osteolysis may destroy large areas of the skeleton before it is detected and result in a sudden fracture due to a weakened skeleton. While there are some short term prospective trials that have shown changes in bone density in the periacetabular region, one needs a biomechanical model to understand factors that influence bone remodeling leading to cyst formation. This study aims to develop a mathematical model for studying the mechanical effects of bone cysts in the acetabulum of THA patients.
2D finite element (FE) models of patients with known restroacetabular cystic disease were generated using coronal CT images from the central region of the acetabulum. The boundary between bone and soft tissue was segmented and an FE model generated. Mesh convergence tests were performed to identify a suitable level of mesh refinement. Three material zones representing– cortical bone (E=17GPa), cancellous bone (E=1GPa) and a titanium cup (E=120GPa) – were included in the model. A series of simulations were run to investigate how cysts affect stress distribution as well as the mechanical consequence of medial wall deficiency.
The presence of a cyst did not alter the pattern of stress distribution in the lateral and medial wall. But the strain energy function increased significantly at the inferior margin of the cyst within its cancellous bone. This may encourage bone formation at the cyst margin and help to explain the sclerotic walls seen in some cysts. Models with absent medial walls showed that both compressive and tensile stresses lowered in the cortical wall and the strain energy function reduced almost to zero. This suggests that a medial wall defect has a high risk of progression.
The current 2D model cannot incorporate complex acetabular geometry or complex forces acting on the hip. Therefore the current model will be further developed into a 3D FE model of the whole pelvis that also represents the pelvic ring structure more adequately. Physiologically meaningful boundary conditions as well as patient specific geometry and material properties will be used to investigate mechanical effects of bone cysts realistically.
Leptin is a major hormonal product of the adipocyte which regulates appetite and reproductive function through its hypothalamic receptors. It has now become clear that leptin receptors are much more widely distributed than just the hypothalamus, and the skeleton has emerged as an important site of action of leptin.
The signalling form of the leptin receptor has been found in several cell types including human osteoblasts, rat osteoblasts and human chondrocytes. In vitro we have shown leptin to an anabolic factor, stimulating osteoblast proliferation and inhibiting osteoclastogenesis. Leptin increases bone mass and reduces bone fragility when administered peripherally but has an indirect inhibitory effect on bone mass via the hypothalamus when administered directly into the central nervous system.
Data from animal models where there is an absence of either leptin production (ob/ob) or its receptor (db/db) have been contradictory. In this study we compared the bone phenotype of leptin receptor-deficient (db/db) and wild-type (WT) mice. Micro-CT analysis was done on proximal tibiae using a Skyscan 1172 scanner. Db/db mice had significantly reduced trabecular bone volume, trabecular thickness and trabecular number and a higher degree of trabecular separation. Cortical bone was also significantly lower in db/db animals in volume, cross-sectional thickness and perimeter.
These results demonstrate that in the absence of leptin signalling there is reduced bone mass indicating that leptin indeed acts in vivo as a bone anabolic factor, mimicking the in vitro results.
Periprosthetic osteolysis is a serious medium to long-term complication of total hip arthroplasty. Interobserver reliability of detecting osteolysis around cementless ace-tabular components is reported to be poor using plain radiographs. Quantitative computed tomography (CT) provides sensitive and accurate measures of osteolytic lesion volume, however, there may remain a role for plain radiographs in monitoring progression of osteolysis. The aim of this study was to use quantitative CT to monitor the progression of osteolytic lesions around cementless acetabular components and to compare plain radiographs and CT in determining the progression of osteolysis.
A high-resolution multi-slice quantitative CT scanner with metal artefact suppression was used to determine the volume of osteolysis around 18 cementless acetabular components. The mean time since arthroplasty was 14 years (range 10–15 years) at the initial CT. Repeat scans of the hip were undertaken over a five-year period to determine progression of osteolysis with time. A second blinded observer examined anteroposterior and lateral plain radiographs taken at the same time as the CT scans and measured the location and area of osteolytic lesions.
CT measurements determined that in ten of 18 hips (56%), osteolytic lesions progressed by more than 1cm3/yr. Progression in size of osteolytic lesions was significantly associated with hips with larger osteolytic lesions at the initial CT (p=0.0005). The mean volume of osteolysis progression was 4.9cm3/year (range 2.8–7.5cm3/yr) for cases with osteolysis volumes greater than 10cm3 at the initial CT, and 0.7cm3/yr (range 0–2.3cm3/yr) for cases with osteolysis volumes smaller than or equal to 10cm3 at the initial CT (p=0.002). Importantly, the rate of osteolysis progression between CT scans varied greatly in some hips. In contrast, using plain radiograph assessment, progression in the area of osteolytic lesions was only detected in 10% of hips.
In conclusion, quantitative CT provides new insights into the natural history of periacetabular osteolysis. Total osteolysis volume greater than 10cm3 is associated with a high risk of progression and progress, on average, at a greater rate than those less than 10cm3. Plain radiographs, including a lateral view, are an unreliable clinical diagnostic tool to predict substantial progression of periacetabular osteolytic lesions.
Implant malposition remains one of the common causes of total knee replacement (TKR) failure and increased wear. Recent advances in computer technology have made available navigation systems for TKR and other orthopaedic procedures. The purpose of our study was:
to develop a method to assess the accuracy of an image-free TKR navigation system; to assess its accuracy in a leg with normal or near-normal mechanical axis; to assess its accuracy in a leg with abnormal mechanical axis.
The system chosen was an image-free system based on electromagnetic technology, the MedTronic AxiEM TKR navigation system. To facilitate measurements, an artificial leg (phantom) was constructed from machined Plexiglas with simulated hip and knee joints. Additional joints located at the midshaft of the tibia and femur allowed deformation in the flexion/extension (y), varus/valgus (x) and rotational (z) planes. Using a highly accurate digital calliper unit (FaroARM Technologies, USA) to precisely measure co-ordinates with pre-machined points on the phantom, a software program was developed to convert these local co-ordinates into a determination of actual leg alignment. This technique was verified using repeated measurement with variable coordinates, giving accuracy to within 0.05 of a degree.
Simulated procedures were then performed with both normal and abnormal leg mechanical axis. At specific points in the procedure, information was compared between the FaroARM digital measurements and the CAS system. Repeated serial measurements were undertaken. In the setting of normal alignment, accuracy to within one degree was demonstrated. In the setting of abnormal x, y and z plane alignment in both femur and tibia, accuracy to within two degrees was demonstrated.
Several clinical studies have been performed to assess the precision of computer navigation in TKR. This study was designed to assess the accuracy of a clinically validated navigation system. The study demonstrates the high level of in-vitro accuracy of the MedTronic AxiEM navigation system in both normal and abnormal mechanical leg alignment settings.
Implant malposition is one of the most common causes of failure in resurfacing arthroplasty of the hip (RAH). Recent advances in computer technology have made available navigation systems for RAH and other orthopaedic procedures. The purpose of our study was:
to develop a method to assess the accuracy of an image-free RAH navigation system; to assess its accuracy in a leg with normal anatomy and with deformity of the proximal femur.
We used the Ci-CAS RAH navigation system (DePuy - BrainLab). To facilitate measurements, an artificial leg (phantom) was constructed from machined aluminium with simulated hip and knee joints. The hip and knee articulating surfaces were synthetic bone material (Sawbones – Pacific Laboratories). An additional joint located at the trochanteric region allowed deformation in varus/valgus and ante/retroversion of the head/neck segment. Using a highly accurate digital calliper unit (FaroARM Technologies, USA) to precisely measure co-ordinates with pre-machined points on the phantom, a software program was developed to convert these local co-ordinates into a determination of actual anatomy and leg alignment. This technique was verified using repeated measurement with variable co-ordinates, giving accuracy to within 0.05 of a degree.
Simulated procedures were performed with both normal and abnormal anatomy of the proximal femur. At specific points in the procedure, information was compared between the FaroARM digital measurements and the Ci-CAS system. Repeated serial measurements were undertaken. In the setting of normal alignment, accuracy to within 0.5 degrees was demonstrated. In the setting of abnormal alignment (varus/valgus and ante/retroversion) of the proximal femur, accuracy to within 2 degrees was demonstrated.
To our knowledge, this is the first study to assess accuracy of a RAH navigation system. The study demonstrates a satisfactory level of accuracy for the Ci-CAS in both normal and abnormal anatomical settings. Currently, no international standard or methodology exists against which these results can be compared. In the near future, introduction of new navigation technologies will make crucial the development of international standards for pre-clinical validation of computer-assisted navigation systems. The present study is a first attempt to address this issue.
Bone fluid flow transports nutrients to, and carries waste from, the bone cells embedded in the bony matrix. In long bones, it is driven by the blood pressure differentials between the medullary cavity and the periosteal surface and it is enhanced by mechanical loading. Loading of bone tissue deforms the bone matrix and changes the volume of the medullary cavity. Both mechanisms alter the interstitial fluid flow in the bone cortex. The former changes the volume of the fluid cavities in the cortex, while the latter modifies the intramedullary pressure (IMP). This study aims to investigate and compare, for the first time, the effects of these two mechanisms combined on the interstitial fluid flow in the bone cortex.
A hydraulic-fluid method is proposed to investigate the enhancement of IMP induced by the external loading. An intact sheep tibia is represented by a hollow cylinder, with the bone marrow being completely constrained in the cavity and assumed to behave as an icompressible liquid. The cortex is supposed to be a purely elastic material, and its permeability is ignored at this stage. The numerical results show that an axial compressive load of 500 N increases the IMP from 4000 Pa to 48900 Pa.
The influence of the enhanced IMP on the interstitial fluid flow is examined in a subsequent poroelastic analysis. At this stage, the cortex is assumed to be a biphasic material that permits fluid perfusion. The poroelastic analyses were conducted for both initial and enhanced IMPs. The results of the simulations demonstrate that the external load induces very high interstitial pressure. The highest pressure could be 25 times higher than the initial marrow pressure, but its magnitude decreases quickly. Furthermore, the influence of the IMP on the interstitial pressure is limited to the inner half of the cortical wall adjacent to the endosteal surface. However, the influence becomes more significant with decreasing load-induced interstitial pressure.
In conclusion, these simulations suggest that the increase in IMP during mechanical loading further enhances interstitial fluid movements in cortical bone, which highlights the importance of mechanical loading for the maintenance of healthy bones.
Volume and density of fracture callus are important outcome parameters in fracture healing studies. These values provide an indication for the recovery of the mechanical function of the bone. Traditionally, fracture callus’ have been evaluated from radiographs, which represent 2D projections of the three-dimensional structures; therefore such an analysis can be affected by many artefacts. With the availability of Computer Tomography (CT) scanners for the evaluation of healing bones, it is now possible to perform precise, three-dimensional reconstructions of the fracture callus and therefore to evaluate true three-dimensional callus volumes and bone mineral densities. We wanted to make use of this technology in the evaluation of a study looking at the healing of a multifragmentary fracture in sheep after 4 and 8 weeks of healing time (Wullschleger et al, ANZORS, 2006). Our goal was to develop a protocol that would allow for the standardised calculation of cortical bone and callus tissue volumes with minimal user influence. Here, we report on the development of this evaluation protocol and some early results.
A clinical CT scanner was used to scan the experimental limbs, immediately after the sheep had been euthanized. Further analysis of the CT dataset was accomplished with the commercial computer software Amira. The region of interest was cropped to a 9 cm section of the bone shaft, guaranteed to comprise the entire fracture callus. Next, the cortical bone and the callus tissue were segmented by choosing appropriate threshold values for the measured grey levels. The volume of the segmented regions was then calculated by the software.
The application of this protocol to six CT scans from our experimental study resulted in average callus volumes of 12.21 ± 1.96 (standard deviation) cm2 after 4 weeks healing time and 14.28 ± 1.58 cm2 after 8 weeks healing time.
In conclusion, we demonstrated the feasibility of using CT data for a quantitative 3D analysis of callus volumes. While this technique is undoubtedly superior to the estimation of callus volumes from two-dimensional radiographs, the absolute accuracy of the results will need to be determined by comparison with histological data.
Volume and density of fracture callus are important outcome parameters in fracture healing studies. These values provide an indication for the recovery of the mechanical function of the bone. Traditionally, fracture callus’ have been evaluated from radiographs, which represent 2D projections of the three-dimensional structures, therefore such an analysis can be affected by many artefacts. With the availability of Computer Tomography (CT) scanners for the evaluation of healing bones, it is now possible to perform precise, three-dimensional reconstructions of the fracture callus and therefore to evaluate true three-dimensional callus volumes and bone mineral densities. We wanted to make use of this technology in the evaluation of a study looking at the healing of a multifragmentary fracture in sheep after 4 and 8 weeks of healing time (Wullschleger et al, ANZORS, 2006). Our goal was to develop a protocol that would allow for the standardised calculation of cortical bone and callus tissue volumes with minimal user influence. Here, we report on the development of this evaluation protocol and some early results.
A clinical CT scanner was used to scan the experimental limbs, immediately after the sheep had been euthanized. Further analysis of the CT dataset was accomplished with the commercial computer software Amira. The region of interest was cropped to a 9 cm section of the bone shaft, guaranteed to comprise the entire fracture callus. Next, the cortical bone and the callus tissue were segmented by choosing appropriate threshold values for the measured grey levels. The volume of the segmented regions was then calculated by the software.
The application of this protocol to six CT scans from our experimental study resulted in average callus volumes of 12.21 ± 1.96 (standard deviation) cm2 after 4 weeks healing time and 14.28 ± 1.58 cm2 after 8 weeks healing time.
In conclusion, we demonstrated the feasibility of using CT data for a quantitative 3D analysis of callus volumes. While this technique is undoubtedly superior to the estimation of callus volumes from two-dimensional radiographs, the absolute accuracy of the results will need to be determined by comparison with histological data.
Bilateral mandibular lengthening is widely accepted during mandibular distraction osteogenesis. However, distraction osteogenesis are sometimes associated with clinical complications such as open bite deformity, lateral displacement of temporo-mandibular joint, premature consolidation and pin loosening. Although distraction osteogenesis aims to develop pure tensile strain on the regenerate tissue however, in real life situation due to differences in device orientation, materials and misalignment it is often subjected to complex stress and strain regimes.
The objective of this study was to characterise the mechanical environment (stress and strain) in the Finite Element Models (FEM) of regenerate tissue during two different device orientations:
(a) device placed parallel to the mandibular body (b) device placed parallel to the axis of distraction.
Furthermore, the influence of misalignment from above two idealised orientations was also investigated.
The distraction protocol in this study was similar to previous study of Loboa et al (2005). FE models were developed at four stages: end of latency, distraction day two, distraction day five and distraction day eight. At each time period a distraction of 1mm was applied to the model as it is most widely used distraction rate. In these models two primary distraction vectors were simulated; first when the device is parallel to the body of the mandible and second when the device is parallel to the axis of distraction.
Results indicate that when the device is placed parallel to the mandible the effect of distraction vector variation due to misalignment in transverse plane (±150 at an interval of 50 ; + indicate lateral and indicates medial) is symmetric and variation in the stress and strain regimes on regenerative tissue are less than 3%. However, when the device is placed parallel to axis of distraction the corresponding change is asymmetric and almost double in magnitude. The greatest differences were seen when misalignment is towards lateral side (+150). Similarly in the sagittal plane variations up to 17% were developed due to 0- 400 change in the distraction vector orientation. Thus the orientation of device which determines the distraction vector plays an important role in determining the mechanical environment around regenerative tissue. The results suggest that implications of misalignment of the device and its sensitivity from the ideal situation should be well understood during clinical planning.
A number of densitometry studies have reported dramatic density losses in the acetabular region after uncemented Total Hip Arthroplasty (THA)1,2. However the mechanical implication of such loss is not yet known. This study aims to perform a mechanical analysis with patient specific Finite Element (FE) models to find out how the stress distribution affects the Bone Mineral Density (BMD) changes after uncemented THA.
An existing patient CT dataset collected for a densitometry study was used to generate patient-specific FE models with a previously validated FE mesh generation method3. Boundary and loading conditions included the hip joint force and the forces of 21 muscles attached to the pelvic bone at eight characteristic phases of a gait cycle 4. Tensile and compressive components of principal stresses were calculated after each simulation.
In general, both compressive and tensile principal stresses decreased after uncemented THA but the magnitude of decrease for tensile stresses was much greater than compressive stresses. The changes in tensile stresses were matched with BMD loss patterns. In particular, the densitometry study revealed that areas dorsal to the prosthesis lost more bone density than areas ventral to the prosthesis1. The stress distribution pattern showed that such areas experienced high tensile stress initially and then a dramatic decrease in their magnitude while their compressive stresses remained relatively unchanged. On the other hand, the regions where BMD was maintained - the areas superior to the cup - experienced high compressive stresses initially, which remained relatively high three years after the surgery.
Although it is a result from one patient, results suggest that changes to tensile and compressive stresses might influence BMD differently after uncemented THA. Our hypothesis is that regions with high tensile stress experience bone loss while BMD of the regions with high compressive stress are maintained. More patient datasets are being processed to test this hypothesis. Findings from this study can explain the phenomena of retroacetabular osteolysis, late migration and implant failure of press-fit cups observed in long-term clinical studies.
We present a retrospective review of 50 cases of cuff tear arthropathy treated over past seven years by the use of reverse geometry shoulder prosthesis. 98% follow-up was achieved with average follow up of 3.04 years. Mean age was 81.3 (SD 9.2) years, female to male ratio was 5:1 and seven patients had bilateral procedures. Pre-operatively patients were assessed with American Shoulder and Elbow Surgeons Scores (ASES) and Oxford Scores and pos-operatively with ASES, Oxford and Constant scores. SF36 score was used to assess functional health status. Mean pre-op ASES was 22.29 (95%CI: 9.1 – 37.9) and post-op ASES score was 65.2 (95%CI: 48.5 – 81.9), (P< 0.001, Paired t-test). Mean post-operative Oxford score was 27.25 (95% CI: 18.4 – 27.6) and mean post operative Constant score was 63.2 (95% CI: 52.6 – 79.6). Sirveaux score was used to grade extent of glenoid notching on AP and lateral glenohumeral views, that showed 69% had notched. Complications included two acromion fractures, two episodes of subsidence with dislocation, one episode of infection and one patient with unexplained pain in axilla. We found reverse geometry shoulder replacement provides reasonable improvement in pain and function in elderly patients with massive cuff tear arthropathy.
To assess the outcome of semi-constrained total elbow arthroplasty (TEA) in osteoarthritis and compare it to the rheumatoid group.
Two groups of patients assessed. In group-one with the diagnosis of rheumatoid arthritis 40 replaced elbows in 31 patients (25 female and 1 male), with average age of 67 (49–82) were reviewed. Group-two consisted of 14 elbows in 14 patients (9 female and 5 male) with post-traumatic osteoarthritis. Average age in this group was 71 (54–84). Mayo elbow performance (MEPS) and Liverpool elbow scores (LES) were used as the outcome measure.
The average follow up for group-one was 53 (20–90) and group-two 60 months (21–103). According to the MEPS 87.1% of patients in group 1 and 63.6% in group 2 had excellent or good outcome (p=0.09). Only one patient from group one and none in group two had the joint revised. No difference was observed in MEPS of group-one (86 ± 17) and group-two (77 ± 24), (p=0.25). Also the LES in the two groups were not different (p=0.85).
The outcome of TEA is satisfactory in both groups. No statistically significant difference was noted in the two groups. The recommendation of TEA in patients with osteoarthritis is supported by this study.
There were no complications in the plate group. There were 9 complications in the K-wire group. Three patients required re-operation (for malunion, median nerve compression, and retrieval of a migrated wire). Remaining complications included: 5 pin-site infections and 1 superficial radial nerve palsy.
Plate fixation achieved statistically significant better radiological and functional results.
Allogenic blood is becoming a scarce commodity, with many advocating autologous retransfusion systems to reduce the transfusion burden post primary arthroplasty. Many units have not embraced this, as the costs involved are perceived to be prohibitively expensive.
The inpatient stays of 149 consecutive patients undergoing primary total knee arthroplasty, performed in a single unit by multiple surgeons, were reviewed. Length of post-operative stays and blood transfusion requirements were noted, and cost implications of allogenic and autologous transfusion determined.
The total post-operative transfusion requirement was 28 units of allogenic blood in 12 patients (8%). The total transfusion cost per patient was £28.80. With the cheapest autologous re-infusion system costing £60.08 per patient, a marginal cost of £31.28 would need to be offset, to make such a system viable solely from an economic point of view. The average post operative stay was increased from 5.6 to7.7 days in those requiring blood transfusion. This extra bed occupancy was estimated to cost a minimum of £42.68 per patient.
Autologous drainage systems not only lessen the risks associated with allogenic blood, but have been shown previously to shorten hospital stay and significantly reduce allogenic transfusion requirement. By doing so, they would easily offset the increased expenditure needed to institute such a system.
Theatre discipline remains a vital adjunct in the fight against infection in joint replacement surgery. The aim of this audit was to compare local theatre practise in two hospitals with that which is recommended in the literature. Factors assessed included the correct use of the ‘plenum’, the application of hats and masks, the opening of theatre doors intra-operatively, and the number of staff in the theatre.
Results suggest that basic principles and practises of theatre antisepsis are not being adhered to during joint replacement surgery. Suggestions are made as to how theatre behaviour may be improved in order to optimise the operating environment.
Hip resurfacing is a relatively new concept in hip arthroplasty, but is being performed more frequently in the United Kingdom.
We compared anteroposterior radiographs of 30 patients who had undergone cemented hip resurfacing (Cormet) with those of 30 patients who had undergone uncemented hip resurfacing (Cormet). All operations were performed using the anterolateral approach. We measured the acetabular offset, femoral offset, stem shaft angle, medialisation of the cup, head/neck ratio, cup height, leg length, and the implant seating pre-operatively, immediately postoperatively and one year postoperatively. The data were analysed by paired t-tests.
There were no significant differences between any of the measurements at all three time periods. This demonstrates no loss of offset, no femoral neck thinning and no leg length reduction. We note a smaller femoral offset and a reduction on average of 2mm in seating of the femoral implant in the uncemented group as compared to the cemented group. This we attribute to movement of the femoral implant in the first year post-operatively, and as such restoration of the femoral offset to the pre-operative level.
We conclude that uncemented hip resurfacing does not show any statistical benefit over cemented hip resurfacing, although we did observe a more accurate reproducible femoral offset with better seating of the implant in the uncemented group. We also note that there was no neck thinning in any of these patients at one year post-operatively.
144 total hip replacements were performed by Swedish Orthopaedic Surgeons at Weston NHS Treatment Centre between 2004–2006, in an attempt to reduce the waiting list in Cardiff. Following concerns regarding the outcome of knee arthroplasty patients, the Welsh Assembly funded a clinical and radiographic review of all hip arthroplasty patients from the same unit.
100 hips were reviewed at a mean follow-up of 24 months. The mean Oxford Hip Score was 30 (range 12–60).
Radiolucencies were seen in acetabular zone 1 in 34, and all 3 zones in 28 hips. Femoral component position was > 4 degrees varus in 41 cases. Medial floor breach with intrapelvic cement was seen in 12 cases. 10 cases had > 1cm leg length discrepancy. There were 3 early dislocations, 1 intraoperative distal femoral fracture, 1 Pulmonary Embolus and 2 superficial infections.
4 patients have received further treatment so far, and 12 have been listed for acetabular component revision for loosening. 1 has been listed for stem revision for symptomatic leg length discrepancy of 2.5cm.
There is an unacceptably high early failure rate in this group of patients. The cost of further investigation and revision surgery far outweighs cost-savings achieved by outsourcing treatment to a distant centre.
There is little evidence from the literature regarding the timing of hip fracture surgery for patients who are on the antiplatelet agent clopidogrel bisulphate (Plavix) (1).
We report the results of a retrospective case control study of 40 patients comparing the timing of surgery for patients taking clopidogrel against a control group of those not taking an antiplatelet agent. Time to surgery, length of stay, transfusion requirements, wound problems and other post operative complications were examined.
Within the study group of patients taking clopidogrel, we also compared those who underwent surgery within four days of stopping the clopidogrel and after four days.
The transfusion requirements were greater in those patients on clopidogrel prior to admission. Wound healing and post operative complications were similar between the two groups. Total length of hospital stay and post operative length of stay were longer in the clopidogrel group.
There was an increase in transfusion requirements and post operative length of stay in patients on clopidogrel undergoing early surgery (within 4 days) compared to the group where surgery was delayed.
We conclude that, in this small study, transfusion requirements and length of stay were greater in patients on clopidogrel. Transfusion requirements and post operative length of stay were also greater if surgery was performed within four days of omitting clopidogrel. Further studies are required to determine optimal timing of surgery following discontinuation of clopidogrel.
Parker et al examined the effect that delay to surgery has on patients with proximal femoral fractures. They found that a delay of more than 48 hours to surgery significantly increased the patient’s length of stay. They examined delays due to lack of theatre resource only.
Therefore an audit was proposed at the RUH Bath to set a standard of care that fracture neck of femur patients should be operated on within 48 hours. One month of data was collected (August 2005) and analysed. Of 52 fracture neck of femur patients 23% were waiting longer than 48 hours. The recommendation was made to have extra lists made available for fracture neck of femur patients.
In January 2006 the elective orthopaedic ward was closed (for 12 days) due to diarrhoea and vomiting. Therefore elective lists were utilised for trauma. The audit was repeated comparing these 12 days with 12 in December. In the December cohort seven neck of femur fracture patients waited more than 48 hours, in the January cohort no neck of femur patient waited more than 48 hours. A further recommendation was made for increased theatre capacity for neck of femur patients.
Subsequent to these recommendations 2 half day fracture neck of femur lists have been added to the rota at the RUH Bath. (Tuesday and Thursday pm). The patients can be assessed and worked up as planned trauma and can be seen in advance by the anaesthetist. Audit of January 2007 fractured neck of femur patients showed that there were 46 patients treated with only 1 waiting more than 48 hours due to theatre capacity.
In conclusion the audit process can work and achieve beneficial results as shown here. An accepted standard of care was taken from the literature, department performance analysed, changes implemented and closure of the audit loop has shown that it has worked.
The data was collected prospectively from admission, and entered onto a database.
1 patient with a short PFNA nail sustained a fracture of the femur through the site of the distal locking bolt during the follow up period and required revision.
The mobility and social function scores were significantly reduced at follow up compared to pre-operative status(p=0.001).All domains of SF36 were low compared to normative data.
All 30 fractures united and there was no migration, lysis around or cut out of the helical blade.In total, 46 distal locking bolts were utilised.4 of these had migrated or become loose.
Patients immobilised in lower limb casts are at risk of venous thrombo-embolism. We have devised a unique patient administered scoring system to provide targeted thrombo-prophylactic therapy based on a patient’s risk factors for thrombo-embolism. This study investigated completion of the risk assessment form and intra-observer error.
We carried out a prospective observational study investigating completion of risk assessment forms in patients attending the fracture clinic who were immobilised in lower limb casts. Each patient completed a form at initial presentation which determined their treatment regime. The patients were asked to complete a second identical form once their plaster was removed together with a short questionnaire asking about ease of use of the risk assessment form.
92 patients were included in the study. The first form was correctly completed by 90 patients (98%) and the second by 89 patients (97%). There was an exact scoring correlation between the two forms in 82% of patients.
93% of patients found the scoring system easy to understand and complete.
We propose that this unique patient administered, venous thrombo-embolism risk assessment form provides a user friendly, practical and reproducible tool for highlighting trauma patients in lower limb casts at increased risk of thromboembolic disease.
Five patients would not have the surgery again. Only two of these had still played sport. Three of these had other knee pathology found at arthroscopy.
We performed a retrospective study of a consecutive cohort of 109 patients, under the age of 60 years, who had either a Patellofemoral replacement (PFR), Uni-compartmental replacement (UKR) or a Total knee replacement (TKR). They were operated on by 2 senior surgeons between 2002 and 2006 at the Avon Orthopaedic Centre in Bristol. The aim of this study was to examine and compare the effect of knee replacement on the employment status of this group of patients.
Demographic and diagnostic data were collected from patient’s hospital records and a detailed questionnaire regarding occupational status sent postoperatively. Of the 109 patients, 37 underwent PFR, 31 UKR and 41 TKR. The study population included 38 men and 71 women and the mean age for both sexes was 53 years (range 40–60 years).
82% of patients who were working prior to surgery and who had either a TKR or UKR were able to return to work postoperatively. Only 54% of those who had a PFR were able to return to work and this was statistically significant when compared with patients in the other two groups p=0.47. The median time for return to work postoperatively for the study population was 12 months. Those in the PFR group took significantly longer to do so (20 months) compared to those who had either a UKR (11 months) or TKR (12 months) p=0.01. Patient’s subjective opinion as to their ability to work following knee arthroplasty was worse in the PFR group p=0.049.
This is the first study to compare employment status following Patellofemoral, Unicompartmental knee and Total Knee Replacement. TKR and UKR are effective in returning patients to active employment and this is typically one year following operation. Those patients who had a PFR did not experience the same benefits in terms of numbers returning to work, time to do so and their subjective opinion as to their ability to cope with normal duties.
56% of open subluxations occurred at L3/4. In closed subluxations the most frequent level involved was LI/2 (36% of cases). Where both subluxations coexisted, the open subluxation was more proximal.
We present a series of 14 patients presenting to the senior surgeon’s practice who sustained thoracolumbar burst fractures, with no neurological loss. The patients were treated with early mobilisation and extension bracing. We assessed their pain and disability, using VAS and ODI, and their fracture morphology. There was no statistical correlation between any measured parameter of fracture morphology and pain or disability. There was correlation between age at injury, time elapsed from injury and psychosocial aspects of the injury and the subsequent disability.
The measured disability was low and compared favourably with the results of studies of patients treated surgically.
We continue to treat all our neurologically intact burst fractures by early mobilisation and bracing, and take no account of fracture morphology in our decision making.
Ankle arthrodesis is a common operation with published fusion rates ranging from 62–100%. The literature documents the difficulties of obtaining arthrodesis in certain patients for example with neuroarthropathy, but the risk of non union related to deformity, bone quality, bone defects and systemic disease has not previously been reported.
Between 2002 and 2006 we performed an ankle arthrodesis in 154 patients, and analyzed these patients retrospectively to delineate categories of risk factors for achieving arthrodesis. From this analysis we devised a preoperative radiographic scoring system to grade complexity of pre-operative ankle arthrodesis. The scoring system is based upon 5 categories; size and plane of deformity, presence and size of bone defects, presence and area of avascular necrosis, site of previous fracture in post-traumatic arthritis and predisposing condition causing the arthritis. Each category has potential scores of 1–5, apart from the latter which is scored up to 6, with higher scores being more severe. The grade of complexity is derived from a cumulative score from all 5 categories.
Statistical analysis revealed good intra and inter- observer correlation. Multivariate regression analysis demonstrated that this scoring system correlates with the techniques used for arthrodesis as well as outcome. This study demonstrated that if the method of arthrodesis is altered according to the relative risk of non –union then there is no significant difference in outcome between patients of high and low risk for non-union
We present a new scoring system for severity of pre-operative condition in ankle arthrodesis patients and introduce an algorithm for surgical correction based upon this pre-operative scoring system. The surgical techniques for the arthrodesis are presented, ranging from simple screw fixation to more complex bone grafting techniques, bone stimulation and alternative methods of fixation.
an osteotomy 10mm proximal to the calcaneocuboid joint line and an osteotomy performed adjacent to the posterior calcaneal facet.
6 revisions (13%) were performed in Group A (5 of these related to instability – all preoperatively varus of > 20 degrees). 10 revisions (8%) were performed in Group B (2 related to instability).
6 ankles underwent intra-operative deltoid release and 6 had pre or post-operative calcaneal osteotomy. Only one of these required revision for instability. 4 ankles underwent post-operative lateral ligament reconstruction. These ankles all failed due to instability.
The mean postoperative American Foot and Ankle Society score in Group A was 85, compared to 78 in Group B.
In 2004, our centre has changed from the “STAR” to the “Mobility” Total Ankle Replacement device and a study was undertaken in order to ascertain if there was a learning curve to useage of this new device and perform a comparison in terms of survival, function, additional procedures and complications.
The indications were 55% osteoarthritis, 30% Rheumatoid and 8% JIA with the remainder being haemophiliac, haemochromatosis and ankylosing spondylitis.
One third of TARs in this unit are combined with additional procedures such as subtalar fusion. Only isolated TARs were considered in this study and the tourniquet time, wound problems, length of stay and known complications for the last 20 STAR TARs was compared to the first 20 Mobility TARs.
68 Mobility TARs have been implanted since Oct 2004 and survival data was collected for this entire cohort and compared to a similar number of STARs.
The survival curve of the mobility and STAR shows no loss of the Mobility due to revision at up to 3 years.
Clinical outcome scores will be presented.
The early results for this new prosthesis show no cause for concern and surveillance is ongoing.
After a mean follow up of 3.2 years 2 patients had died and 9 patients had required further surgery: Implant removal for infection (1); Talar revision for loosening (1); Re-fusion of the syndemosis (4); Removal of syndesmosis screws (3); Calcaneal osteotomy for valgus hindfoot (1).
The NHS will soon implement 18 week referral to treatment targets.
A prospective study was performed whereby from 2004–6, referral letters from General Practitioners suggesting a diagnosis specifically of Morton’s neuroma, resulted in randomised assignment to either direct referral for USI or to the specialist Foot and Ankle outpatient clinic.
Patients with less specific referral letters were evaluated in clinic and referred for USI as appropriate.
A comparison was made of the sensitivity and specificity of the referral pathways, financial implications and the time to treatment (TTT).
Of 57 patients for whom the GP had diagnosed a MN, 40 (70%) had the diagnosis confirmed on USI (other diagnoses were: 7 NAD, 3 ganglions, 2 bursae, 2 degenerative change, 1 glomus tumour, 1 angioleiomyoma, 1 SOL); this was comparable to the overall number referred to radiology with a suspected MN (69%).
In the directly referred group, the mean TTT was 115 days (95%CI = 89 – 141), compared to 241 days (95%CI = 223 – 259) for those patients who went via a Foot and Ankle clinic. P< 0.0001.
The mean wait of this group is within the 18 week government target without any changes to our current radiology protocols. Using this direct referral protocol we saved 29 outpatient appointments; if followed for all eligible patients we would have saved 57 outpatient appointments.
Using the three responsive scores there was a significant improvement in outcome with operative intervention (p< 0.0001) with each score. Using the SRM and the ES, the AOS showed the highest level of responsiveness. It also showed an increased response rate suggesting that patients find it more useable.
Outcomes were assessed by overall subjective satisfaction, Visual Analogue Scale (VAS) for pain, functional scores, range of motion and radiographic evaluation.
6 patients (9%) complained of persisting mild to moderate pain and swelling in the joint. 2 patients (3%) were not happy with the level of deformity correction. All the above 8 patients declined to have joint arthrodesed. 2 patients (3%) had deep infection requiring implant removal. 1 patient had osteolysis on the x-rays but remain asymptomatic. Although radiographic deterioration of the implant was demonstrated in a lot of implants, this deterioration did not correlate with patient satisfaction.
We conclude that silastic first metatarsophalangeal joint replacement is a proven procedure that not only provides long- term pain relief but also satisfactory range of movement. Therefore it should still be considered as an option in patients with end-stage hallux rigidus.
We have also used this view successfully for injecting local anaesthetic in the tarso-metatarsal joints to elucidate the exact source of pain.
We recommend this simple view should be routinely used in addition to the standard AP, lateral and oblique views of the foot for mid foot injuries.
The screws were pulled out using a materials testing machine. Stiffness, force, displacement, and energy required were recorded.
Furthermore, the increasing incidence of multi-resistant bacteria is a concern to all. The Scottish Health Executive has identified the rationalisation of antibiotic prescribing as one of the principal means of reducing the development of these organisms.
In addition, Orthopaedic Consultants in the west of Scotland were contacted asking whether they use antibiotics in hallux valgus surgery and what their perception of infection risk was.
Thirty-five consultants replied, of which 15 regularly performed surgery for hallux valgus. Prophylactic antibiotics were used by seven, with the average perception of infection risk 4%.
In addition, using the characteristics of the inserted screw as a scaleable marker, it was calculated what would have been the optimum length of screw thread in order to maximise screw thread length in the target bone whilst preventing the screw threads being across the fusion site.
Currently available screws have thread lengths that are either too long (breaching the fusion site) or too short for ideal fixation and we propose a different thread length to those currently available.
However, even with current screws, we found no correlation between thread length, thread positioning across the fusion site and non-union.
These radiological outcomes were compared with alignment outcomes for ‘Star’ total ankle replacement, as published by PLR Wood. (Total Ankle Replacement JBJS April 2003 85B, pg 334)
32/35 Angle A were within the published accepted range (850–950). 23/35 Angle B were within the published accepted range (800–900). 35/35 Angle C were within the published accepted range (200–400)
No statistical difference between the distribution of angle A, B and C and the means for A, B and C for the published results.
A lower angle B positions the implant on metaphyseal bone with a risk of subsidence. Comparing Angle B with a modified acceptable range (850–950) 31/35 fell in the new range.
One of the criteria associated with success after hallux valgus surgery is reduction of the forefoot width. A new parameter called the metatarsal span can be a reliable objective measure to assess reduction of forefoot width and outcome after surgery for hallux valgus.
Between 1998 and 2007, fifteen patients with haemophilia A underwent 21 ankle arthrosco-pies+/− arthroscopic cheilectomy in order to attempt symptomatic relief of arthrosis and to increase the range of motion. All patients had severe degenerative changes radiologically.
Perioperative management was shared with our local dedicated Haemophilia service and the management algorithm will be presented.
Outcome data for pain and range of motion shows only moderate benefits.
Two patients had good relief of symptoms for 6 months. Two patients however chose to return for arthroscopies to the contralateral ankle and two had arthoscopies to the same ankle.
Follow up data is not currently available for 4 patients and the rest required fusion with a median time to fusion of 1 year.
Two patients had a documented increased range of motion, but one of these patients had an increased level of pain associated with the increased mobility.
There was 1 major complication, namely an aneurysm of the tibialis anterior artery.
Two patients had recurrent bleeds following surgery requiring ongoing and prolonged factor VIII treatment.
Average patient stay was 3.1 days, range 2 to 5 days and this stay is shorter for later years than earlier years.
The post-operative requirement for extra factor VIII ranged from 4 postoperative doses to 3 weeks ongoing treatment, median 10 doses. The average cost per dose was approximately £1128, giving a median cost of £11280 per case.
In summary, this procedure seems to be expensive in terms of QALY gains and has low rates of success in terms of function and pain relief.
There was one case of superficial wound infection, deep vein thrombosis, neuroma and delayed union of medial malleolus each.
The original procedure involved application of a plaster backslab following surgery, change of cast on day 1 post operatively, suture removal and plaster change at two weeks post-operation and cast removal or bivalving six weeks post-operation, following outpatient review.
The new procedure utilised a reusable cast applied in theatre which allowed suture removal and wound inspection in the community and outpatient review at six weeks without plaster change.
A screw that has any thread across the fusion site can not offer any compression and may be postulated to lower the rate of fusion. Similarly, maximal screw thread in the target bone would optimise fixation.
This retrospective study calculates the ideal characteristics of a screw used for ankle arthrodesis, and assesses the correlation between the lack of compression and non-union.
Of the 64 ACE screws, 8(12.5%) had threads across the TT joint, representing 7(21.9%) of all posterior screws and 1(3%) of all anterior screws in the study. The mean length of screw-threads into the TT joint was 2.1mm(range 0.53 to 4.06 mm). The ST joints were breached by 4(6.25%) screws(all posterior). The mean length of protrusion was 1.8mm(range 0.28 to 3.89mm). No screw thread crossed both TT and ST joints simultaneously.
No non-unions were recorded in either group.
In the belief that many of the barriers that patients face when deciding upon an ankle or hindfoot fusion procedure stem from inadequate information about the procedure and its outcomes, the novel concept of a “Fusion forum” has been developed: a nurse-led informal group meeting to facilitate patients’ understanding and perception of fusion procedures. The aims were to provide more in-depth information than it is possible to deliver during the limited time of an initial doctor-patient consultation, to get the patient to meet and question a guest (an expatient who has previously had a fusion procedure) and to allow patients time to reflect upon their choices.
The value of the fusion forum has been evaluated by a questionnaire which was completed by the first 48 patients who attended the forum. 96% (46/48) of respondents felt that the quality of information that they were given was excellent or good. No respondent thought that the information was unsatisfactory. Patients were asked how valuable they had found meeting the guest. Four patients did not respond to this question. All of the respondents thought that meeting another patient who had already undergone the procedure was excellent or good
The mechanics of setting up a foot and ankle fusion forum is discussed, along with the lessons learnt from the first cohort of patients. This process has been found to greatly increase patient understanding of arthrodesis. It has been found during the consent process in pre-admission clinic that patients demonstrate a more in-depth understanding of the operative procedure, a more comprehensive knowledge of what the whole process involves, as well as the relative risks and benefits and the expected time of recovery.
We present a retrospective comparative review of the radiological outcomes of Chevron and Scarf with Akin osteotomy in the treatment of hallux valgus.
The mean post-operative intermetatarsal angles (IMA) were: Chevron mean 8.050, standard deviation 2.560, standard error 0.57. Scarf with Akin mean 7.220, standard deviation 2.56, standard error 0.57. The difference in postoperative IMA between the two groups did not achieve statistical significance.
The mean change in IMA for each was: Chevron mean increment 4.90 Standard deviation 2.290, standard error 0.51. Scarf with Akin mean increment 6.680, standard deviation 4.130, and standard error 0.88. The difference in alteration of IMA between the two groups did not achieve statistical significance.
Following ankle sprain, there can be many causes of disability including ligament injuries, soft tissue or bony impingement, Peroneal tendon tears, osteochondral defects (OCD), synovitis and Osteoarthritis (OA)
In 43 of the 46 available notes the patients presented with either chronic ankle pain or instability following ankle sprain. 32 had Anterolateral soft tissue impingement on arthroscopy. Of these 24 had MRI scans with only 3 reporting a soft tissue impingement.
13 patients had lateral ligament reconstruction. All 13 of these patients showed signs of instability on examination under anaesthesia (EUA). Of these 9 had MRI scans with 4 reporting a ligamentous injury. Five other patients had MRI scans that showed a lateral ligament injury but had a normal EUA and did not undergo a ligament reconstruction.
10 patients had moderate to severe OA on arthroscopy of the ankle. Of these 4 had MRI scans with 2 reporting OA changes but 2 reported as OCD.
The decision to reconstruct/repair the lateral ligament complex is a clinical one dependent on patient symptom and the EUA findings.