Purpose: Few functional outcomes of total femoral endoprosthetic replacement (TFEPR) using contemporary modular systems are available. We compared functional results between TFEPR patients receiving fixed- and rotating-hinge knee componentry following oncologic resections.

Method: Eighteen TFEPR patients were identified from a prospectively gathered sarcoma database. Six were secondary procedures and 12 primary. Four patients had metastatic carcinoma, 8 osteosarcoma, 4 non-osteogenic spindle cell sarcomas of bone, 1 Ewing’s sarcoma, and 1 femur-invading soft-tissue sarcoma. All reconstructions used modular implants from a single company. Proximally, all were bipolar hip hemiarthoplasties, 12 including abductor reattachment. Distally, 8 had fixed- and 10 had rotating-hinge knee componentry. Toronto Extremity Salvage Score (TESS), and both Musculoskeletal Tumor Society Scores (MSTS) were compared between fixed- and rotating-hinge groups using the Mann-Whitney test.

Results: Complications included 1 hip dislocation, 1 femoral malrotation, and wound problems requiring 3 debridements and 1 amputation. One metastatic carcinoma patient developed local relapse. Follow-up averaged 4 years (range 1 month to 14 years). At latest follow-up, 10 patients had died of disease. Eight remained alive, 6 disease-free, 2 with distant disease. Among patients surviving 6 months, 6 used no assistive devices, 5 used a single cane, and 4 were wheelchair bound, each at least partly due to distant disease progression. TESS averaged 74.5±17.4, MSTS1987 25.2±4.4; and MSTS1993 58.6±22.9 among the 12 patients for whom functional results were available from latest follow-up. No statistically significant differences or even trends were detected between fixed-hinge and rotating-hinge patients (lowest p = 0.755), but both instability problems were in the rotating-hinge group.

Conclusion: While both rotating- and fixed-hinge TFEPR reconstructions may function well, consideration should be given to fixed-hinge knee reconstruction when massive myectomies or poorer conditioning make hip and knee stability a primary concern in the short-term.

Objectives: We aimed to assess the incidence of requirement for shoe raises for a leg length discrepancy (LLD) after total hip replacement (THR). We also assessed the patient satisfaction with, and continued use of shoe raises for symptomatic LLD after THR.

Methods: We searched the orthotics records at our institution to identify all patients who had required a shoe raise for symptomatic LLD after primary unilateral total hip replacement between January 2003 and October 2008. 75 patients were identified. 72 were still alive. In the same period 4270 primary hip replacements were carried out at the institution. A questionnaire was sent out to all living patients. Patient details (including satisfaction) and operative details were recorded. Pre-operative and post-operative radiological measurements of leg length discrepancy (LLD) were performed.

Results: The incidence of requirement of a shoe raise for LLD after THR at our institution was 1.8%. 68% were women. 84% of questionnaires were returned. 31% had stopped using their shoe raise completely. Two-thirds of patients found the raise improved their symptoms of a LLD. Symptoms causing dissatisfaction with the shoe raise included new or worsening back pain, limp, uneven walking, self awareness, need to adjust trouser length, pain in other hip, discomfort while walking, and difficulty buying shoes. Patient overall satisfaction with their THR was poor in the patients who were dissatisfied with the shoe raise, but was good in those who found the raise useful.

Conclusion: About 2% of patients may require a shoe raise for symptomatic LLD after THR. Of these 65% will find the shoe raise helpful. Patient with a LLD after a THR that is not helped by a shoe raise are very dissatisfied. It is important that surgeons should take great care to avoid causing a LLD after THR as it can be a cause of very low patient satisfaction.

Introduction: Pseudotumours (soft-tissue masses relating to the hip joint) following metal-on-metal hip resurfacing arthroplasty (MoMHRA) have been associated with elevated serum and hip aspirate metal ion levels, suggesting that pseudotumours occur when there is increased wear. This study aimed to quantify in vivo wear of implants revised for pseudotumours and a control group of implants revised for other reasons of failure.

Methods: A total of 30 contemporary MoMHRA implants in two groups were investigated in this Institutional Review Board approved study:

8 MoMHRA implants revised due to pseudotumour;

The linear wear of retrieved implants was measured using a Taylor-Hobson Roundness machine. The average linear wear rate was defined as the maximum linear wear depth divided by the duration of the implant in vivo.

Results: In comparison with the non-pseudotumour implant group, the pseudotumour implant group was associated with:

significantly higher median linear wear rate of the femoral component: 8.1um/year (range 2.75–25.4um/year) vs. 1.79um/year (range 0.82–4.15um/year), p=0.002; and

Similarly, differences were also measured in absolute wear values. The median absolute linear wear was significantly higher in the pseudotumour implant group:

21.05um (range 2.74–164.80um) vs. 4.44um (range 1.50–8.80um) for the femoral component, p=0.005; and

Wear on the acetabular cup components in the pseudotumour group always involved the edge, indicating edge-loading of the bearing. In contrast, edge-loading was observed in only one acetabular component in the non-pseudotumour group of implants. The deepest wear was observed well within the bearing surface for the rest of the non-pseudotumour group. The difference in the incidence of edge-loading between the two groups was statistically significant (Fisher’s exact test, p=0.03).

Discussion: Significantly greater linear wear rates of the MoMHRA implants revised due to pseudotumour support the in vivo elevated metal ion concentrations in patients with pseudotumours. This study provides the first direct evidence to confirm that pseudotumour is associated with increased wear at the MoM articulation. Furthermore, edge-loading with the loss of fluid film lubrication may be the dominant wear generation mechanism in patients with pseudotumour.

The National Institute for Clinical Excellence, UK published guidelines in 2007 encouraging the use of low molecular weight heparin (LMWH) joint replacement surgery. Subsequently, our hospital adopted these guidelines in the treatment of total hip replacements. This study is based on our prospective database of total hip replacements between 2005 and 2009 and compares the complication and mortality rates pre- and post institution of the NICE guidelines.

We analysed prospectively collected data on 686 patients who underwent a primary total hip replacement done by a single surgeon between January 2005 and April 2009. We compared the incidence of mortality, pulmonary embolism, myocardial infarction and intracranial bleeding between the two groups. Prior to the guidelines, all patients were treated for the duration of their admission with 75mg aspirin followed by 4 weeks after discharge. Subsequent to the guidelines, the treatment changed to 40mg of LMWH (Clexane) while an inpatient with aspirin being prescribed for 4 weeks on discharge. Patients unable to tolerate aspirin were treated with low molecular weight heparin. High risk patients (previous pulmonary embolism, previous deep vein thrombosis, family history) were treated with 6 weeks of warfarin. Each patients was reviewed at 8 weeks and 6 months following surgery, and adverse incidents were documented at each review or incident.

Results: 686 patients were identified from the study – 328 pre and 358 post implementation of the NICE guidelines. In the pre-guideline group the mortality was 0.6%, with the incidence of pulmonary embolism being 0.3%, myocardial infarction 0.9% and intracranial bleed 0.3%. Both complications of myocardial infarction occurred early in the post-operative stage and were fatal. The post-guideline group had a mortality rate of 0.2%, with the incidence of pulmonary embolism being 0.2% and intracranial bleeding 0.2%. No myocardial infarctions were noted in this group. The single death was as a result of an intracranial bleed. The was no significant statistical difference in the incidence of mortality, pulmonary embolism, myocardial infarction or intracranial bleeding between the two groups (p value > 0.05, 95% confidence interval). There were no complications in the warfarinised patients of which there were equal numbers in both groups (16).

Conclusion: This study has shown that the change in thromboprophylaxis has not had a significant effect on complication rates in primary total hip replacements and that our mortality rate (0.4%) compares favourably with recent literature. The lack of complications in the war-farinised group probably reflects that high risk patients were identified in the screening process and commenced on warfarin early in the post operative period. Note must be made of the single death due to an intracranial bleed while on low molecular weight heparin.

Background: Thumb carpalmetacarpal joint (CMCJ) osteoarthritis has been treated using various combinations of resection, interposition and replacement arthroplasties. The procedure of choice for various stages of CMCJ osteoarthritis remains controversial. This study compares the short term outcomes of trapeziectomy alone and trapeziectomy with PI2 implantation.

Methods: A cross-sectional observational study involving 33 patients (36 thumbs). 18 thumbs had trapeziectomy alone and 18 had trapeziectomy and PI2 implantation. Underlying indication was osteoarthritis in 35 thumbs and trauma in one thumb. Preoperative radiological assessment using the Eaton and Glickel grading for CMCJ osteoarthritis and clinical review including DASH and SF-36 score was performed at a mean follow-up of 18 months. Preoperative and postoperative pain level was assessed using Visual Analogue Scale (VAS) and satisfaction of the surgery using the Likert 5-point scale.

Results: There were 30 women and 3 men. The average age at follow up was 61 years (range 45 to 75). There was no significant difference between the two groups regarding age, duration of symptoms, and stage of disease, preoperative pain score and handedness. The mean DASH score at follow up was 26.8 for trapeziectomy alone group and 35.4 for the PI2 arthroplasty group. Preoperative to postoperative VAS for pain showed an improvement from fair to excellent in 60% of patients in trapeziectomy alone group and 30% of the patients in the PI2 arthroplasty group. There was no significant difference in the SF-36 scores between the two groups in all health domains. 6 out of 16(38 %) patients in the PI2 group had multiple surgeries mainly due to dislocation or subluxation of the implant. The overall Likert 5-point scale scores were highest for trapeziectomy alone group with 70% very satisfied compared to 40% in the PI2 arthroplasty group.

Conclusion: The early results of pyrocarbon PI2 arthroplasty show a high complication rate compared to simple trapeziectomy. The high rates of subluxation and dislocation observed in the early cohort resulting in multiple surgeries may be attributed to steep learning curve of the surgical technique and creation of a shallow groove for the implant. This may have contributed to the low satisfaction levels observed in PI2 arthroplasty group. Simple trapeziectomy provides satisfactory outcome in more than 80% of the patients.

Introduction: Metal on metal hip resurfacing arthroplasty-induced pseudotumours are a serious complication, which occur in 4% of patients who undergo this procedure. The aim of this study was to measure the 3D in vivo wear on the surface of resurfacing components revised for pseudotumour, compared to a control group.

Method: Thirty-nine hip resurfacing implants were examined; these were sourced from our institutions prosthesis retrieval bank. They were divided into two groups; 22 patients with a clinical and histopathological diagnosis of pseudotumour and 17 controls. Patient demographics and time to revision were known. Three dimensional contactless metrology (Redlux™ Ltd) was used to scan the surface of the femoral and acetabular components, to a resolution of 20 nanometers. The location, depth and area of the wear scar was determined for each component. Volumetric wear was determined, along with the presence of absence of edge-loading. A separate blinded analysis to determine the presence of absence of impingement was performed by one of the authors. ANOVA was used to test for differences in wear and Fishers Exact test was used to compare the incidence of edge-loading between the groups.

Results: The volumetric wear rate for femoral component of the pseudotumour group was 4.7mm3/yr (SD3.5) and 1.7 mm3/yr (SD1.5) for the control group (p=0.03). In the pseudotumour group, the volumetric wear rate of the acetabular component was 3.5 mm3/yr (SD3.6) compared to 0.02 mm3/yr (SD0.07) for the control group (p=0.01). Edge-loading was detected in 74% of acetabular components in the pseudotumour group and 22% of those in the control group (p=0.01). Anterior or posterior edge-loading, consistent with impingement was present on the femoral components of 73% of patients in the pseudotumour group and 22% in the control group (p=0.01).

Discussion: This work demonstrates that implants revised for pseudotumour have significantly higher volumetric wear rates than controls. They also have a significantly higher incidence of edge-loading and impingement than controls. Edge-loading significantly increases wear. We suggest that pseudotumours are caused by high concentrations of metal wear debris, which have been shown to have a toxic effect on osteocytes and macrophages. This is the one of the first studies to demonstrate a clear link between pseudotumours and increased bearing surface wear. It is also the first to demonstrate that edge-loading, due to impingement, occurs in a significant number of patients who develop this condition. Improved implantation techniques and resurfacing designs may help avoid this serious complication of hip resurfacing.

Introduction: The use of second generation highly cross-linked polyethylene (HXLPE) is now commonplace for total hip arthroplasty, however there is no long-term data to support its use. Hip simulator studies suggest that the wear rate of HXLPE is ten times less than conventional polyethylene (UHMWPE). The outcomes of hip simulator studies are not always reproducible in vivo. Long term clinical data is required, as there is emerging clinical data, which suggests that some types of second generation HXLPE may have increased wear after 5 years.

Method: A prospective double blind randomised control trial was conducted using Radiostereometric analysis (RSA). Fifty-four subjects were randomised to receive hip replacements with either UHMWPE liners or HXLPE liners. All subjects received a cemented CPT stem and uncemented Trilogy acetabular component (Zimmer, Warsaw, IN, USA). The 3D penetration of the head into the socket was determined to a minimum of 7 years.

Results: The total liner penetration was significantly different at 7 years (p=0.01) with values of 0.33mm (SD 0.17mm) for the HXLPE group and 0.51mm (SD 0.14mm) for the UHMWPE group. The steady state wear rate from 1 year onwards was significantly lower for HXLPE (0.003 mm/yr, SD 0.04 mm/yr) than for UHMWPE (0.03 mm/yr, SD 0.03 mm/yr) (p=0.01). The direction of wear was in the antero-medial direction in both groups.

Conclusion: We have previously demonstrated that the penetration in the first year is creep-dominated, from one year onwards the majority of penetration is due to wear. The wear rate of this second generation HXLPE approaches that of metal on metal bearings. Second-generation HXLPE may have the potential to reduce the risk of revision surgery, due to wear debris induced osteolysis.

Introduction: Metal-on-metal hip resurfacing arthroplasty (MoMHRA) has gained popularity as an alternative to THR for younger patients with osteoarthritis. A growing concern has been the association of MoMHRA with the development of inflammatory pseudotumours (IP), especially in women. These have been linked to metal-on-metal wear, which can be related to metal ion concentrations. Elevated metal wear debris levels may result from impingement, rim contact and edge loading. Head-neck ratio (HNR) is a predetermining factor for range of movement and impingement. Neck thinning is a recognised phenomenon post-MoMHRA and we have found an association of IP with increased neck thinning based on a case control study. Our aims were to identify HNR changes a hip undergoes when resurfaced and at follow up; and whether greater neck thinning at follow-up could be associated with the presence of elevated metal ions.

Methods: A cohort of 91 patients (57M:34F) with unilateral MoMHRAs were included in this study. Blood tests were obtained at a mean follow up of 3.9 years (range 1.7–7 years) and serum (Co:Cr) ion levels were measured (ICPMS). High metal ion concentrations were defined as Co> 4.1ppb and Cr> 5.2ppb. For all patients, head-neck ratio (HNR) was measured on plain anterio-posterior pelvic radiographs pre-operatively, immediately post-operatively and at follow-up.

Results: Female patients had significantly bigger HNR pre-op (mean=1.35, range:1.22–1.64) compared to males(mean=1.22, range:1.05–1.38) (p< 0.01). Immediately post-op, female HNRs (mean: 1.26, range: 1.14–1.34) were not different to male patients(mean=1.24, range=1.11–1.38) (p=0.11). At follow-up HNR was once again significantly bigger (p< 0.01) in females (mean=1.35, range: 1.21–1.49), compare to males (mean=1.27, range:1.11–1.38). HNR alterations with operation (p=0.00) and at follow-up (p< 0.01) were significantly bigger in female patients. Furthermore, there was a significant correlation between high ion levels and HNR change at follow-up for both Co (p=0.02) and Cr (p< 0.01).

Conclusion: This study identified gender-specific changes in HNR that resurfaced hips undergo, not previously documented. Female hips have greater HNR pre-operatively, compared to male hips, and appear to be biomechanically disadvantaged when resurfaced. A decrease in HNR with resurfacing could result in impingement and lead to processes, known to be more prevalent in females, such as neck thinning, increased wear and IP development. In addition, we highlight a correlation between high ion levels and greater neck thinning at follow-up. Increased neck thinning in symptomatic MoMHRA hips could be secondary to increased wear and should be investigated further radiologically for the presence of IP.

The objective of this study was to determine the effectiveness of screening and successful treatment of methicillin-resistant Staphylococcus aureus (MRSA) colonisation in elective orthopaedic patients on the subsequent risk of developing a surgical site infection (SSI) with MRSA.

We screened 5933 elective orthopaedic in-patients for MRSA at pre-operative assessment. Of these, 108 (1.8%) were colonised with MRSA and 90 subsequently underwent surgery. Despite effective eradication therapy, six of these (6.7%) had an SSI within one year of surgery. Among these infections, deep sepsis occurred in four cases (4.4%) and superficial infection in two (2.2%). The responsible organism in four of the six cases was MRSA. Further analysis showed that patients undergoing surgery for joint replacement of the lower limb were at significantly increased risk of an SSI if previously colonised with MRSA.

We conclude that previously MRSA-colonised patients undergoing elective surgery are at an increased risk of an SSI compared with other elective patients, and that this risk is significant for those undergoing joint replacement of the lower limb. Furthermore, when an infection occurs, it is likely to be due to MRSA.

The scarcity of mesenchymal stem cells (MSCs) in iliac crest bone marrow aspirate (ICBMA), and the expense and time in culturing cells, has led to the search for alternative harvest sites. The reamer-irrigation-aspirator (RIA) provides continuous irrigation and suction during reaming of long bones. The aspirated contents pass via a filter, trapping bony fragments, before moving into a ‘waste’ bag from which MSCs have been previously isolated. We examined the liquid and solid phases, performed a novel digestion of the solid phase, and made a comparative assessment in terms of number, phenotype and differentiation capacity with matched ICBMA.

The solid fraction from the filtrate was digested for 60 minutes at 37°C with collagenase. Enumeration was performed via the colony-forming unit fibroblast (CFU-F) assay. Passage (P2) cells were differentiated towards osteogenic, adipogenic and chondrogenic lineages, and their phenotypes assessed using flow cytometry (CD33, CD34, CD45, CD73, CD90, and CD105).

MSCs from the RIA phases were able to differentiate at least as well as those from ICBMA, and all fractions had phenotypes consistent with other established sources. The median number of colonies for the three groups was: ICBMA = 8.5 (2 to 86), RIA-liquid = 19.5 (4 to 90), RIA-solid = 109 (67 to 200) per 200 μl. The mean total yield of cells for the three groups was: ICBMA = 920 (0 to 4275), RIA-liquid = 114 983 (16 500 to 477 750), RIA-solid = 12 785 (7210 to 28 475).

The RIA filtrate contains large numbers of MSCs that could potentially be extracted without enzymatic digestion and used for bone repair without prior cell expansion.

Anthrax is extremely rare in the western world but is endemic to areas of south and central Asia. In early 2010 an outbreak was identified in heroin-injecting intravenous drug users in the United Kingdom and Europe. Afghanistan is currently the principal source of heroin which reaches the United Kingdom. When anthrax occurs, cutaneous disease accounts for over 95% of cases. At least 47 cases with 13 deaths have been confirmed so far. We present three cases presenting during this time with marked swelling, one resulting in compartment syndrome but all with an absence of the expected cutaneous appearances.

We suggest that rather than cutaneous anthrax, these patients represent a new subcutaneous presentation of anthrax.

This paper describes the presence of tenodesis effects in normal physiology and explores the uses of operative tenodesis in surgery of the upper limb.

Thirty-five patients were followed prospectively from their referral to the Problem Fracture Service with chronic osteomyelitis of diaphyseal bone between November 1994 and June 1999.

The patients were treated using a closed double-lumen suction irrigation system following reaming and arthroscopic debridement of the intramedullary canal; this is a modified system based on the work of Charles Lautenbach. Results of these procedures were regularly followed up in clinic, and between June and July 2007 the whole cohort was reviewed via postal questionnaire, telephone and case note review.

At a mean follow up of 101 months, 26 were living with no evidence of recurrence, 4 had died of unrelated causes with no evidence of recurrent infection. Four patients had persisting problems with sinus discharge requiring intermittent antibiotic therapy and 1 patient had his limb amputated for recurrent metaplastic change.

These results gave this cohort an 86% clearance of infection, with recurrence in 12%, which is comparable to the Papineau and Belfast techniques with significantly less surgical insult to the patient.

Introduction: Giant cell tumour of bone (GCTB) is an expansile osteolytic tumour of bone which contains numerous osteoclast-like giant cells. GCTB is a locally aggressive tumour which can cause extensive bone destruction that can be difficult to control surgically, up to 35% of cases recurring after simple curettage. Bisphosphonates are anti-resorptive agents that have proved effective in the treatment of a number of osteolytic conditions.

Methods: This study reports results from four European centres where bisphosphonates are being used to treat problematic GCTBs. Details of treatment with bisphosphonates of 25 cases of primary, recurrent and metastatic GCTBs was assessed clinically and radiologically.

Results: Most primary/recurrent tumours did not exhibit progressive enlargement and, in some cases, both primary and metastatic GCTBs showed a degree of radiological improvement following treatment. Some patients also noted relief of pain following treatment. In a few cases, no apparent treatment effect was noted and there was disease progression. Several inoperable large spinal/pelvic GCTBs remained stable in size following treatment.

Discussion: Our findings provide preliminary evidence for the use of bisphosphonates to inhibit the progressive osteolysis associated with GCTB. These agents had a beneficial clinical and/or radiological effect in most cases. This study reports results from four European centres and highlights the fact that these centres are all employing different clinical indications and different regimes of bisphosphonate treatment. Bisphosphonates have significant side effects and indications for treatment and standardisation of drug type and dosage regimes (and measurement of agreed outcome measures to determine treatment efficacy) should be established for the use of these agents to control GCTB tumour growth and osteolysis.

From 2004–2006, in an attempt to reduce the waiting time for patients listed for total knee and total hip arthroplasty at Cardiff and Vale NHS Trust, 156 total hip replacements (THRs) were performed by Swedish Orthopaedic surgeons at an NHS treatment centre in England.

All patients were contacted and invited to a review appointment with a Consultant specialising in hip and revision hip replacement. Oxford Hip Scores and clinical and radiographic evaluation were performed. Patients who declined an appointment were sent a postal questionnaire. Radiographs were analysed for component position, radiolucent lines, medial floor breach, leg length discrepancy.

One hundred and thirteen hips were reviewed at a mean 23 month follow-up. The mean Oxford score was 26. Mean age at surgery was 69. Cemented THR was performed in 104 hips; hybrid in 7; cementless in 2. The Exeter stem and Cenator cemented cup were used in the majority of cases. 16% had acetabular inclination greater than 55 degrees. Radiolucent lines around the cup were seen in 76/113 hips. Femoral stem position was greater than 4 degrees varus in 47/113. Medial floor breach seen in 13/113. 10/113 had leg length discrepancy > 1cm. There were 3 dislocations, 1 femoral fracture, 1 pulmonary embolus, 3 deep infections, 2 superficial infections.

Revision surgery has been performed in 18/113 – the majority for a painful loose acetabular component. A further 5/113 have been recommended for surgery. The further surgery rate was 12% at 2 year follow-up.

The revision rate far exceeds the 0.5% 5-year failure rate reported in the Swedish Registry for the components used. This initiative has left a legacy of unhappy patients, and increased the workload required in our unit to correct the problems. The lack of long-term ownership of patients may be an important factor.

Roentgen Stereophotogrammetric Analysis (RSA) can predict long-term outcome of prostheses by measuring migration over time. The Exeter femoral stem is a double-tapered highly polished implant and has been shown to subside within the cement mantle in 2 year RSA studies. It has a proven track record in terms of long-term survivorship and low revision rates. Several studies have demonstrated excellent clinical outcomes following its implantation but this is the first study to assess stem migration at 10 years, using RSA.

This is a single-centre study involving 20 patients (mean age: 63 years, SD=7) undergoing primary total hip replacement for degenerative osteoarthritis using the lateral (Hardinge) approach. RSA radiographs were taken with the patient bearing full weight post-operatively, at 3, 6, 12 months and at 2, 5 and 10 years follow-up. The three-dimensional migration of the Exeter femoral stem was determined.

The mean Oxford Hip Score at 10 years was 43.4 (SD=4.6) and there were no revisions. The stems subsided and rotated internally during a 10-year period. The mean migrations of the head and tip of the femoral stem in all three anatomic directions (antero-posterior, medio-lateral & supero-distal) were 0.69 mm posterior, 0.04 mm lateral and 1.67 mm distal for the head and 0.20 mm anterior, 0.02 mm lateral and 1.23 mm distal for the tip. The total migration at 10 years was 1.81 mm for the head and 1.25 mm for the tip.

The Exeter femoral stem exhibits migration which is a complex combination of translation and rotation in three dimensions. Comparing our 10 year with our previous 2 year migration results, the Exeter stems show continued, but slow distal migration and internal rotation. The subsidence continues to compress the cement and bone-cement interface which maintains secure fixation in the long term.

We aimed to evaluate the effects of implementing blood conservation strategies on transfusion requirements in adult patients undergoing scoliosis correction surgery. We retrospectively studied 50 consecutive adult patients who underwent scoliosis correction surgery (anterior, posterior or combined) between 2003 and 2007. All patients had a standard transfusion protocol. Age, BMI, pre and post operative haemoglobin, levels fused, duration of surgery, hospital stay, anti-fibrinolytics used and blood transfused was noted.

50 patients with mean age 24.6 years and mean BMI 21.9 kg/m2 were studied. 14 patients had anterior surgery, 19 patients had posterior surgery and 17 had combined anterior and posterior procedures. Mean number of levels fused was 9.5 (6–15) and mean duration of surgery was 284.6 minutes (135–550 minutes). Antifibrinolytics were used in 31 patients (62%), Aprotinin in 21(42%) and Tranexamic acid in 10 (20%). Mean blood loss in patients who received anti fibrinolytics was 530mls while mean blood loss in the other patients was 672mls. (p< 0.05). Blood transfusion was not required in any of the patients undergoing anterior correction only while 7 patients (41%) undergoing anterior and posterior correction and 3 patients (15.8%) undergoing posterior correction only required blood transfusion. Mean volume of cell saved blood re-transfused was 693.8 mls and mean hospital stay was 9.2 days. Mean pre-op haemoglobin was 13.2 g/dl (10.4–17.4) and mean post-op haemoglobin was 10.7 g/dl (7.7–15). 4 patients (8%) required intra and post-operative blood transfusion while 6 patients (12%) required blood transfusion postoperatively.

In conclusion, the use of anti-fibrinolytics like Aprotinin and Tranexamic acid reduces blood loss in scoliosis surgery. In the current scenario, with Aprotinin no longer available for use, our study would recommend the use of Tranexamic acid alongwith other blood conservation measures. In our unit we do not have blood cross matched for anterior surgery alone.

Introduction: Revision hip surgery is predicted to rise significantly over the coming decades. There is therefore likely to be an increasing need to overcome the large bone loss and cavitatory defects encountered in failed primary hip replacements. Impaction bone grafting (IBG) is a recognised technique for replacing lost bone stock. Achieving optimal graft impaction is a difficult surgical skill with a significant learning curve, balancing the need to achieve sufficient compaction to provide primary stability versus the need to keep impaction forces to a minimum to prevent iatrogenic fracture. In this study we have developed a revision acetabular model to test the hypothesis that the use of vibration and drainage with a new custom made perforated tamp could reduce the peak stresses imparted to the acetabulum during the impaction process and also improve the reliability and reproducibility of the impaction technique

Methods: Composite Sawbone hemi Pelvis models were used, with identical contained cavitatory defects created (Paprosky Type 2a). A strain gauge was attached to the medial wall of each hemi pelvis. A custom set of IBG tamps were made, and coupled a pneumatic hammer used to generate the vibrations. A standard impaction technique was used for the control group and the new vibration impaction for the experimental group. The cavity was progressively filled with morsellised allograft in 6 set steps for both groups with strain gauge readings taken during all impaction to monitor peak stresses. A standard Exeter Contemporary cup was then cemented into the graft bed for both groups. The models were mechanically loaded according to the protocol developed by Westphal et al at the angle of the joint reaction force during heel strike for a total of 50 000 cycles. 3D assessment of any micro motion post mechanical testing and degree of graft compaction was done with high resolution micro CT.

Results: Vibration impaction lead to a significant reduction in the peak stresses during the impaction process throughout the 6 steps (e.g. Step 1: 34.6 vs 110.8 MPa p=0.03). There was also far less variability in the peak stresses in the vibration group compared to standard impaction both in sequential impactions by the same surgeon and between different surgeons. One medial wall fracture occurred in the control group only. There was no difference in the degree of graft compaction or in the subsidence of the implant post cyclical loading.

Conclusion: Impaction bone grafting can be a difficult surgical skill with a significant learning curve. We believe that this new technique of applying vibration coupled with drainage to the IBG process in the acetabulum can reduce the risk of intraoperative fracture whilst achieving good graft compaction and implant stability. This technique therefore has the potential to widen the ‘safety margins’ of IBG and reduce the learning curve allowing more widespread adoption of the technique for replacing lost bone stock.

The CMI pyrocarbon implant is a unipolar arthroplasty for trapeziometacarpal joint arthritis which is implanted in to the thumb metacarpal. Previous case series have shown these implants provide significant pain relief and good patient satisfaction. We report the first cases of pyrocarbon hemiarthroplasty from Peterborough.

Seventeen cases in fifteen patients were retrospectively reviewed. The average patient age was 59.7 years (range 47–72). 7 patients were men and 8 were women. Five were discharged with good outcome at a mean of 11.5 months (range 6–19). One failed to attend follow up.

Most patients in whom the implant survived were afforded good pain relief by the procedure and had a good functional range of thumb movement. Radiologically 8 implants were subluxed by at least 50%. One implant was revised after dislocation and loosening of the prosthesis which was associated with trauma. She made excellent clinical progress after revision of the prosthesis. One of the thirteen cases dislocated and was revised to a trapeziumectomy after 11 months.

Preliminary results suggest that this implant affords good pain relief and functional improvement in managing OA at the TMC joint. Longer term follow up will be required to correlate clinical and radiological outcomes.

To assess the outcome of knee “arthrodesis” using cemented Endo-Model knee fusion nail in failed Total Knee Replacement (TKR) with significant bone loss due to infection. This is a retrospective case study of seven patients with infected TKR and multiple surgeries with significant bone loss.

All patients had antibiotic loaded cement with a temporary K-nail as a first stage procedure to eradicate infection. All seven patients had “arthrodesis” performed using cemented modular Endo-Model Knee Fusion nail (Waldemar Link, Hamburg) by the senior author. Cement was used to hold the stems in the diaphyses and not used around the coupling mechanism. The “arthrodesis” relied entirely on the coupling mechanism which has been shown to have good axial and torsional rigidity by mechanical testing. Outcome was assessed using pre and post Visual Analogue Score (VAS).

Mean age was 72.3 years(62–86). Mean follow up was 39.6 months (7–68). The VAS pain score improved from pre-operative mean score of 7.9 to a postoperative score of 1.5. One patient suffered fracture of femoral cement mantle at 50 months who underwent a technically easy exchange revision. One patient had recurrent infection with distal femoral fracture at 36 months and was revised to distal femoral replacement.

The Endo-Model knee arthrodesis nail restores limb lengths, has good early results in terms of pain relief and provides a stable knee “arthrodesis” in cases where there is significant bone loss and extensor mechanism insufficiency following an infected TKR.

Introduction: Impaction bone grafting (IBG) using fresh frozen morsellised allograft is considered by many as the method of choice for replacing lost bone stock encountered during revision hip surgery. Bone marrow contains multipotent skeletal stem cells which have the potential to differentiate down a number of different cell lineages including osteoblasts, chondrocytes and adipocytes. In IBG it is desirable for as many as possible to go on to form bone rather than fibrous tissue to form a solid osseous construct. Whilst it is possible to push cells down the osteogenic lineage in vitro, some of these methods (e.g. the addition of Dexamethasone) are not translatable to clinical practice due to undesirable side effects. In this study we test the hypothesis that by coating the allograft with type 1 Collagen prior to seeding with human bone marrow stromal cells (hBMSC), the cellular adhesion and proliferation down an osteogenic lineage can be increased, leading to improved mechanical and biological properties of the IBG composite.

Methods: A control group of plain allograft and three experimental groups where used to determine the effects that collagen and hBMSC have on IBG (both individually and in combination). The samples where impacted in standardised fashion previously validated to replicate Femoral IBG, and cultured in vitro for 2 weeks. The samples then underwent mechanical shear testing giving a family of stress strain curves for each group, from which a Mohr coulomb failure curve can be plotted. Using the Mohr Coulomb failure equation τ = σ tanΦ + c, the shear strength (τ), Internal friction angle (tanΦ) and inter particulate cohesion (c) can then be calculated. Biochemical analysis was also performed for DNA content and Osteogenic activity.

Results: Mechanical shear testing demonstrated a significant improvement (p=0.002) in the grafts ability to resist shear with the coating of Collagen and seeding with hBMSC (245 vs 299 kPa) as well as improved cohesion between the bone graft particles (46 vs 144 kPa). Regression analysis of the shear strength showed a linear increase with compressive stress (R2 > 0.98) for all groups, indicating that the grafts satisfied the Mohr Coulomb failure law. In the two groups seeded with cells, the collagen coated group also showed increased osteogenic cell activity compared to the plain allograft.

Conclusion: This study has shown a role in the improvement of the mechanical and biological properties of IBG coated with type 1 Collagen and seeded with hBMSC. Collagen coating of IBG is a facile process and translation of the technique into the theatre setting feasible. The improvement in shear strength and cohesion could lead to earlier weight bearing for the patients and allow quicker recovery. The therapeutic implications of such composites auger well for orthopaedic applications. We are currently strengthening the above findings with an in vivo study.

Introduction: The Ionising Radiations Medical Exposure Regulations Act 2000 has established diagnostic reference levels for radiological examinations, however at present there are no national guidelines available for orthopaedic trauma surgery. There may be a role for the introduction of diagnostic reference levels at a local level therefore we studied patient area dose and screening time for orthopaedic trauma operations performed in the Regional Trauma Centre in Northern Ireland.

Methods: Retrospectively data was retrieved from written radiography records in the Royal Victoria Hospital, during the period of 1st January 2007 to 31st December 2007 for all orthopaedic trauma cases in which an image intensifier was used. The screening time, patient area dose (PAD), details of the operation, patient age, sex, month of the operation and grade of the operating surgeon (trainee or consultant), were recorded.

Results: 1709 cases using image intensifier were reviewed. 137 cases were excluded due to incomplete data. 319 hips were screened for insertion of sliding hip screw, mean screening time was 0.51min with a mean PAD of 145cGycm2. 127 femoral nails were inserted with an average screening time of 1.84min and mean PAD of 310cGycm2. 166 tibias were screened for application of Ilizarov frame or insertion of tibial nail, average screening time was 3.00min with a mean PAD of 48cGycm2. 129 spinal cases were screened with an average screening time of 0.80mins and mean PAD of 37.9cGycm2. Consultants had lower screening times and mean PADs than trainees with 0.63min versus 1.01min and 65.8cGycm2 versus 70.9cGycm2.

Conclusions: The average screening times and mean PADs compared favourably with local reference guides for image intensifier cases and with other published series. Every trauma unit should have local reference ranges for orthopaedic imaging cases and regular audit should be carried out to assess compliance with these ranges.

Background: The simultaneous occurrence of spina bifida occulta (SBO) and spondylolysis has been noted previously. The occurrence of SBO and spondylolysis are approximately 17% and 5% respectively.

Aims: The aim of this study was to determine the incidence of SBO when a symptomatic spondylolysis has been proven.

Method: Analysis of four years of lumbar spine CT scans was performed. Patients with spondylolysis or spondylolisthesis caused by a pars defect were identified. These patients’ CT images were then reviewed to establish the patients who also had SBO.

Results: In this unit 650 CT scans of lumbar spines were performed in the last five years. Of these scans 100 (15%) were found to have a pars defect. The average age was 34.6. On CT 30 (30%) patients were shown to have SBO. Of the total 23 were under 18 years old and 13 (56%) of these patients had SBO associated with the spondylolysis. In the over 18 year olds 21 (27%) patients had SBO associated with spondylolysis.

On review of the 550 other scans the average age was 51.9 years old. The incidence of SBO within this group is 10%. Only 6% of these patients were under 18. Out of these 33 patients 30.3% (10 patients) had SBO. Over 18 the incidence of SBO was only 8.5%.

Conclusions: Our results indicate that the occurrence of SBO within the group with a spondylolysis is much higher than in the group where no spondylolysis is present. There is higher incidence of SBO in the younger patients with spondylolysis. 56% of paediatric patients with symptomatic spondylolysis will have SBO. Clinicians should be aware of this fact preoperatively to decide on the technique of repair of the symptomatic lysis.

Introduction: Measurements taken from digital radiographs and corrected for the labelled scale do not correspond to actual clinical dimensions accurately.

Methods: The routine radiographs taken of 30 hip hemi-arthoplasty patients were used to make measurements in the region of the hip. 15 patients were compared in two hospitals using different digital imaging processing. The images were scaled to 100% (actual size), three blinded measurements were taken of the prosthetic femoral head and the average calculated. These results were compared to the actual size of the implanted prosthesis. Further analysis was carried out to determine true magnification.

Results: A consistent difference was observed between measured dimensions at 100% scale and known actual prosthesis dimensions. It was identified that the magnification factor ranged from 110 to 115% with at average magnification factor of 113%. No significant difference was observed between the two hospital systems.

Discussion: Many factors influence radiographic magnification, including variations in distances from x-ray source to patient and from x-ray source to x-ray plate. Angulation and degree of divergence of the x-ray beam and rotation of a limb also influence the magnification which occurs. Accurate measurements can only be taken from digital x-rays if appropriate calibration is performed.

We have evaluated the difference in the migration patterns over two years of two cementless stems in a randomised, controlled trial using radiostereophotogrammetric analysis (RSA). The implants studied were the Furlong HAC stem, which has good long-term results and the Furlong Active stem, which is a modified version of the former designed to minimise stress concentrations between the implant and bone, and thus to improve fixation.

A total of 23 Furlong HAC and 20 Furlong Active stems were implanted in 43 patients. RSA examinations were carried out immediately post-operatively and at six, 12 and 24 months post-operatively.

The subsidence during the first year in the Furlong HAC stem, was approximately one-third that of the Furlong Active stem, the measured mean subsidence of the femoral head at six months being 0.27 mm (95% confidence interval (CI) 0.03 to 0.51) and 0.99 mm (95% CI 0.38 to 1.60), respectively (p = 0.03). One Active stem continued to subside during the second year. All hips, regardless of the type of stem were clinically successful as judged by the Oxford hip score and a derived pain score without any distinction between the two types of stem.

The initial stability of the Furlong Active stem was not as good as the established stem which might compromise osseo-integration to the detriment of long-term success. The changes in the geometry of the stem, to minimise stress have affected the attainment of initial stability.

We present a retrospective review of 167 patients aged 18 years and under who were treated for chronic haematogenous osteomyelitis at our elective orthopaedic hospital in Malawi over a period of four years. The median age at presentation was eight years (1 to 18). There were 239 hospital admissions for treatment during the period of the study. In 117 patients one admission was necessary, in 35 two, and in 15 more than two.

A surgical strategy of infection control followed by reconstruction and stabilisation was employed, based on the Beit CURE radiological classification of chronic haematogenous osteomyelitis as a guide to treatment. At a minimum follow-up of one year after the end of the study none of the patients had returned to our hospital with recurrent infection.

A total of 350 operations were performed on the 167 patients. This represented 6.7% of all children’s operations performed in our hospital during this period. One operation only was required in 110 patients and none required more than three. Below-knee amputation was performed in two patients with chronic calcaneal osteomyelitis as the best surgical option for function. The most common organism cultured from operative specimens was Staphylococcus aureus, and the tibia was the bone most commonly affected. Polyostotic osteomyelitis occurred in four patients. We believe this is the largest reported series of patients treated for chronic haematogenous osteomyelitis.

Pseudotumours are a rare complication of hip resurfacing. They are thought to be a response to metal debris which may be caused by edge loading due to poor orientation of the acetabular component. Our aim was to determine the optimal acetabular orientation to minimise the risk of pseudotumour formation.

We matched 31 hip resurfacings revised for pseudotumour formation with 58 controls who had a satisfactory outcome from this procedure. The radiographic inclination and anteversion angles of the acetabular component were measured on anteroposterior radiographs of the pelvis using Einzel-Bild-Roentgen-Analyse software. The mean inclination angle (47°, 10° to 81°) and anteversion angle (14°, 4° to 34°) of the pseudotumour cases were the same (p = 0.8, p = 0.2) as the controls, 46° (29° to 60°) and 16° (4° to 30°) respectively, but the variation was greater. Assuming an accuracy of implantation of ± 10° about a target position, the optimal radiographic position was found to be approximately 45° of inclination and 20° of anteversion. The incidence of pseudotumours inside the zone was four times lower (p = 0.007) than outside the zone.

In order to minimise the risk of pseudotumour formation we recommend that surgeons implant the acetabular component at an inclination of 45° (± 10) and anteversion of 20° (± 10) on post-operative radiographs. Because of differences between the radiographic and the operative angles, this may be best achieved by aiming for an inclination of 40° and an anteversion of 25°.

Purpose of the study: The purpose of this study is to present our initial experience of single stage revision surgery for infected total knee arthroplasty (TKA).

Methods and results: 12 patients underwent single stage revision for infected TKA. The average patient age was 72.5 years and M: F was 2:1. 5 of the 12 patients had frank infection with presence of discharging sinuses pre-operatively. The procedure involved explantation, debridement, subtotal synovectomy, use of high pressure carbon dioxide (Carbojet) and re-implantation using revision prosthesis and antibiotic laden cement. Utmost care was taken to restore the balance and stability of the revised knee. All the patients were given appropriate intravenous and oral antibiotics in the peri-operative period. Oxford knee scores (OKS) were obtained pre-operatively and at the latest follow-up. Patient satisfaction was also assessed.

At the latest follow-up, none of the patients had recurrence of the infection nor did they need any further surgical procedure. There was no radiographic evidence of loosening of the prosthesis. The OKS had improved from a mean of 17 pre-operative to 41 at the latest follow-up. All the patients were extremely satisfied with the outcome.

Conclusion: Knee function and patient satisfaction improved significantly after single stage revision for infected TKA. None of the patients needed further surgery in the short term. Early results are very encouraging and this change in practice may save on costs and patient morbidity associated with the second stage.

Objectives: To ascertain the frequency and causes of both re-admissions and re-visits (i.e. those not requiring overnight stay) to the hospital following primary and revision TKRs.

Methods: All TKRs performed between April 2007 and March 2008 were included in the study. Mean follow-up period was 9 months (range 3–15 months). Patient data was accessed via computerized patient information systems giving access to the details of inpatient admissions, A& E attendances, laboratory results, radiology reports and clinic letters. Pattern of re-hospitalisation with regards to the cause and time period post-surgery was recorded as well.

Results: Total number of primary TKRs performed in the year was 839 and the re-admission and re-visit rates were 8.22% and 4.17% respectively. The overall re-hospitalisation rate was 12.4%. Most common causes for readmission were pain/stiffness requiring MUA (1.67%) and superficial infections (1.55%). Majority of the revisits were for continuing joint pain (1.67%) and suspected DVT.

Total number of revision TKRs was 136 with a readmission and re-visit rate of 9.7% and 1.49% respectively. The total re-hospitalisation rate was 11.19%. Deep Infections were a prominent cause of readmission (4.4%).

Discussion: Around half (49.5%) of re-hospitalisations were seen in an Orthopaedic setting, the remainder presented to A& E (19.23%), Medical Assessment Units (16.35%) or General Medical Wards (7.7%). Following a primary TKR DVT/PE rates were less than 1% (0.83%). A vast majority (48.6%) of all re-admissions however, occurred within 28 days of discharge. The tradition of seeing patients for the first time in clinic postoperatively after 6–12 weeks may not be appropriate if the majority of re-admissions occur within 28 days.

Conclusion: Idiopathic joint pain and early infections are a major cause of re-hospitalisation. Re-scheduling the first follow-up appointment within the first month after a joint replacement can decrease the overall re-hospitalisation rates and also decrease the impact of these patients on other departments.

Giant cell tumour of bone (GCTB) is an expansile osteolytic tumour of bone which contains numerous osteoclast-like giant cells. GCTB is a locally aggressive tumour which can cause extensive bone destruction that can be difficult to control surgically, up to 35% of cases recurring after simple curettage. Bisphosphonates are anti-resorptive agents that have proved effective in the treatment of a number of osteolytic conditions.

In keeping with its known effect on osteoclasts, we found that the aminobisphosphonate zoledronate abolished in vitro lacunar resorption in cultures of osteoclasts isolated from GCTB. The effect of zoledronate and other bisphosphonates on 15 cases of recurrent primary GCTB, four of which had metastasised to the lung, was assessed clinically. Most recurrent tumours did not exhibit progressive enlargement and, in some cases, both primary and metastatic GCTBs showed a degree of radiological improvement following treatment However, tumours did not diminish in size and, in some cases, no apparent treatment effect was noted.

Our findings provide in vitro evidence for the use of bisphosphonates to inhibit the progressive osteolysis associated with GCTB. In vivo, these agents produced a degree of clinical and radiological improvement in some cases. This study reports results from three European centres where bisphosphonates are being used to treat recurrent GCTB and highlights the fact that these centres are all employing different clinical indications and different regimes of bisphosphonate treatment. Bisphosphonates have significant side effects and indications for treatment and standardisation of drug type and dosage regimes (and measurement of agreed outcome measures to determine treatment efficacy) should be established before these agents are included as part of a treatment protocol to control GCTB tumour growth and osteolysis.

Introduction: Percutaneous in situ pinning of severe SUFE can lead to problems. We describe our technique and results for surgical dislocation to reduce severe SUFE.

Method: Ganz’s approach of greater trochanteric flip, safe dissection and surgical dislocation to preserve the femoral head blood supply was followed to anatomically reduce the femoral head. We have treated 16 cases in this way, but describe nine with a minimum follow up of 2 years. Their mean age was 13.6 years (9 to 16 years). All had severe SUFE with four acute on chronic and two unstable slips. Two were previously pinned and another had a partially fused growth plate. The mean follow up was 3.1 years (2.1 to 4.6 years).

Results: All patients had a good to excellent outcome. Their pre-operative deformity was 84 degrees (65 to 110) measured by AP and cross table lateral x-rays, CT or MRI scans. The average hip external rotation deformity was 70 degrees. Post operatively internal and external rotation and all other movements were similar to the contra-lateral uninvolved hip. None developed avascular necrosis (AVN) or chondrolysis

Conclusions: This technique is demanding but can give good results for severe SUFE.

Background: Satisfaction following anterior and/or posterior spinal fusion varies greatly between individuals. The aim of this study was to assess patient satisfaction with the post-operative scars following surgical correction of scoliosis.

Methods: Prospective study; 31 patients (range 10–37 years), minimum of 2 months post-operation, interviewed in clinic or over the telephone using a questionnaire.

Results: Overall, 18 (58%) patients were disappointed with their scar; it was not what they expected, Patients with anterior scars or both anterior and posterior scars were the most disappointed groups.

39% of patients felt they were inadequately informed or not informed of the nature of scar. However, over 50% of those who had a specialist spinal nurse (SSN) consultation reported the scar to be as they expected. Scar length was the main source of disappointment. 55% reported their scars as being raised (keloid), particularly at the ends. Scar colour and shape was an issue for 23%, whilst 39% experienced prolonged healing. 19 patients had a pre-op consultation with the SSN, 11 did not get this opportunity, 1 declined.

Conclusion: Clearly there’s a need for improved education and understanding with regard to the nature of the scoliosis surgical scar(s). Input from a SSN is important and surgeons must clarify exactly what they mean when discussing operations with patients. This could be done with the aid of pictograms or leaflets detailing issues discussed in consultations along with the opportunity to meet patients who have already had surgery. These measures may lead to increased patient satisfaction with surgery.

Ethics approval: Audit

Interest Statement: None

Introduction: As knee arthroplasty is becoming more commonplace in the working population its outcome and probability of return to work is of interest. Despite a wealth of anecdotal evidence about patient return to work post knee arthroplasty there is nothing published in the recent literature. The NHS Direct patient information website quotes patients return to work about 6 to 8 weeks post knee arthroplasty. In order to address this lack of informed information we conducted a retrospective survey.

Methods: 148 consecutive patients of working age, who underwent knee arthroplasty in 2007 were identified by our Electronic Patients Record. (52 male, 96 female, average age 58 years (range 37–65 years)) They were asked to complete a simple questionnaire relating to their occupational history, arthroplasty satisfaction and their current working capacity.

Results: Our survey had a response rate of 67% (99/148 responders, 64 female and 35 male), with a range of follow up from 7 to 19 months. 39% of patients were in employment at the time of their arthroplasty, with 46 % (46/99) returning to some working capacity post surgery. 32% (32/99) patients were able to return to their exact same employment. 88% (28/32) of these patients had worked up to the date of their arthroplasty. There was no correlation between operative indication or type of prosthesis implanted and patients who returned to employment and those who did not.

Conclusion: Despite high expectation in lay literature of ability to work post knee arthroplasty, only 46% of our patients returned to any form of employment. For patients who returned to work, the duration of sick leave prior to their surgery was a strong predictor of whether they returned to any form of employment. Caution must be exercised when informing patients of likelihood of return to work post knee arthroplasty.

Introduction: Plastic deformation of the regenerate bone is a complication noted soon after limb lengthening. However, less is known about the factors responsible for the development of plastic deformation.

Materials and Methods: Retrospective analysis of 35 X-rays of achondroplast children who had limb lengthening were reviewed. The study compared Monofocal Vs Bifocal and Long lengthenings(> 10 cms) Vs modest lengthenings(≤ 10 cms) of tibial lengthening. Other parameters included in study were Bone healing Index, total length gained and sagittal and coronal axial deformities. There were 20 females and 15 males, 21 long lengthenings and 14 modest lengthenings in the study. The joint orientation and diaphyseal angles(antero-posterior and lateral X-ray views) was used for the measurement of plastic deformation of the regenerate bone.

Results: The mean age at operation was 10 years (range; 6–16 years). There were 29 cases of monolateral fixator and 6 of Ilizarov ring fixator, Of which 26 had monofocal lengthening and 9 had bifocal lengthening (34 callotasis and 1 chondrodiastasis). The total average length gained was 10 cms (range; 23–152). The mean bone healing index and external fixation index/time were 41 days and 352 days respectively. Plastic deformation of the regenerate bone was seen in 26 cases in total. 24 out of 29 cases of monolateral fixator (82%) developed plastic deformation. 44%(4/9) of bifocal group and 84%(22/26) of monofocal group showed evidence of plastic deformation. The long lengthenings showed plastic deformation in 85% (18/21) of the cases, whereas only 57%(8/14) of the cases were positive in modest lengthening group. Most of the axial deviation was in the coronal plane in 92% (24/26) and the sagittal plane accounted to only 23%(6/26) requiring surgical correction.

Conclusions: Long lengthenings and monofocal techniques showed more plastic deformation than bifocal and short lengthenings. However, Ilizarov ring fixator with bifocal corticotomy seemed to be promising with less association with the above entity in our recent experience.

Aim: To review our experience with epiphysiodesis using three different methods to correct LLD and to establish the efficacy of these procedures.

Method: A retrospective review of 42 patients from 1999 to 2008 with at least one year follow-up recorded type and location of the epiphysiodesis, average operating time and hospital stay, complications, method of prediction, timing and the final LLD. CT scanograms and mechanical axis view with grids were used to assess LLD.

Results: Epiphysiodesis was as per Canale for 26, by Metaizeau screw in 14 and by staples in 2. Average operation time was 42 minutes for Canale type, 45 minutes for the screws and 56 minutes for the staple cases. The pre operative LLD of 3.7 cms In the Canale group, improved to 1.2 cms over an average follow-up of 2.1 yrs. There were 4 minor and 2 major complications with a 92% success rate. For the screw group, the mean change was 1.8 cms over 2.2 yrs with 2 minor and 2 major complications giving a success rate of 85%. With staples the success rate was 100% and the mean change was 1.8 cms at an average of 2.3 yrs. In 14 cases where bone age reports were available, the multiplier method seemed better at predicting estimated LLD at skeletal maturity and timing of epiphysiodesis than the Moseley chart.

Conclusions: Percutaneous epiphysiodesis by any method is reliable, minimally invasive and with acceptable complication rate when compared to a corrective osteotomy or open Phemister-type epiphysiodesis. Our experience suggests that the Canale method has the least complications and best success rate. Paleys multiplier method was better at predicting LLD and timing of epiphysiodesis than the Moseley Chart.

Aim: To review our experience with hemi-epiphysiodesis using different methods for the correction of angular deformity about the knee.

Method: This was a retrospective review of 73 patients (101 knees) who underwent hemi-epiphysiodesis from 1999 to 2008. Assessment looked at the type and degree of deformity, implants used, average operating time and hospital stay, complications, degree of correction and the average time to correction.

Results: There were 50 boys and 23 girls with bilateral deformity in 28 cases. There were 88 valgus and 13 varus knees. Average follow-up was 17 months. Staples were used in 28 cases, “8” Plates in 24, Screws in 16 and Drilling in 5 cases. The distal femoral physis was involved in 46 knees, the proximal tibial physis in 21 and both physes in 34 knees (total 135 physes). Average operation time and hospital stay were similar for all methods. There were 6 minor and 3 major complications with staples with an average correction time of 14 months, 3 minor complications with an average correction time of 11 months with “8” plates, 3 minor and 1 major complication with an average correction time of 14 months with screws and 1 minor complication with drilling with an average correction time of 13 months. The outcome was considered as resolved in 47 and pending in 26 cases, with all showing progressive correction of deformity.

Conclusions: Hemi-epiphysiodesis by any method is an effective way to correct angular deformities about the knee in skeletally immature individuals within a reasonable time limit and with minimal morbidity when compared to a corrective osteotomy. Our experience suggests that “8” plates achieve faster correction with the least complications when compared to other methods. Valgus knee deformities corrected faster than varus ones.

Introduction: Impaction bone grafting (IBG) for revision hip surgery can be a difficult surgical skill with a fine line between construct failure from insufficient compaction and intraoperative fracture from high impaction forces. Following on from our experience in the femur, in this study we used an acetabular model to test the hypothesis that the use of vibration for IBG could reduce the peak stresses thus reducing the intraoperative fracture risk and also improve the reliability and reproducibility of the impaction technique.

Methods: Revision hemi pelvis models were made (Pra-prosky Type 2a). A standard impaction technique was used for the control group, and the impactor tamps were coupled with a pneumatic hammer for the vibration group. The cavity was filled in 6 set steps with strain gauge readings taken throughout. The pelvis construct was then mechanically loaded. Graft compaction and micro motion post mechanical testing was assessed with micro CT.

Results: Vibration impaction led to a significant reduction (p=0.03) in the peak stresses during the impaction process. There was also significantly less variability in peak stresses for the vibration group compared to standard, both in sequential impactions by the same surgeon and between different surgeons. One medial wall fracture occurred in the control group only, similar to fractures encountered in the clinical situation. There was no significant difference in the degree of graft compaction or in the subsidence of the cup.

Discussion: We believe that this new technique of applying vibration to the IBG process can reduce the risk of intraoperative fracture whilst achieving good graft compaction and implant stability. This technique therefore has the potential to widen the ‘safety margins’ of IBG and reduce the learning curve allowing more widespread adoption of the technique for replacing lost bone stock.

Aim: To review our practice of performing two-stage revision for infected total knee arthroplasty by using articulating interval prosthesis and short course parenteral antibiotic therapy

Patients and Methods: We included 70 patients treated by a single surgeon using a uniform protocol since 2001. All patients were planned to have two- stage revision for infected total knee arthroplasty with an articulating interval prosthesis made up of cruciate retaining femur and all poly tibia at stage one. All patients were given short course parenteral antibiotic therapy (5 days IV) followed by and 6 weeks dual oral therapy.

Results: The average age was 68 yrs at the time of first stage. Five patients required repeat of 1st stage procedure because of persistent infection. Twenty six (40%) patients opted not to have a 2nd stage procedure because of eradication of infection after 1st stage and good functional result with interval prosthesis. We had recurrence of infection in 6 patients after two-stage procedure at a mean follow up of 42 months. Four patients out of these six had multiple surgeries for infection before our two-stage protocol

Conclusion: Articulating interval prosthesis gives excellent function and also makes subsequent revision easier with well preserved soft tissue balance. It also takes pressure off on the time constraint for the 2nd stage and good number of them may not require a 2nd stage at all. Our results of recurrence are comparable with published literature evidence and we don’t think that prolonged parenteral antibiotics therapy is required provided adequate surgical debridement has been performed.

The aim of this study was to evaluate the impact of a preoperative education programme on length of hospital stay for primary and revision knee arthroplasty patients.

The programme was introduced at our hospital in October 2006 to encourage patients to play an active role in their postoperative recovery process. It was delivered by a multi-disciplinary team consisting of an arthroplasty nurse, ward physiotherapist, occupational therapist and orthopaedic consultant. Patients were educated about their care pathway, knee surgery, pain management, the expected discharge goal, post operative inpatient and outpatient rehabilitation. Data was prospectively reviewed for 472 patients who underwent (primary or revision) knee arthroplasty for the period between January 2006 and November 2007. There were 150 patients in the Conventional group and 322 patients in the Educational group. The mean length of stay reduced significantly from 7 days in the Conventional group to 5 days in the Education group (P< 0.01). In addition 20 percent more patients were discharged early (within 1 to 4 days) in Education group compared to the Conventional group (P< 0.01). There was no statistically significant difference in the percentage of inpatient complications and readmissions between the two groups.

Our study demonstrates that preoperative education is a safe and effective method of reducing length of stay for knee arthroplasty patients. Significantly more patients achieved discharge within four postoperative days.

Introduction: Obligatory external rotation during flexion is well recognised as a cardinal feature of Slipped Upper Femoral Epiphyses (SUFE). We have evaluated the significance of acetabular version in contributing to the external rotational deformity that is seen in otherwise normal hips. We present a small case series focussing on the characteristics of this pathology, highlighting its significance and outlining a treatment strategy.

Method: Five patients (eight hips) presented with disabling hip pain during non-sporting activities. All their hip radiographs had been reported as normal. The rotational profile of both acetabulum and femur in these patients was evaluated by MRI and CT scans.

Results: Clinical examination revealed otherwise normal hips but for an external rotation deformity which got worse on hip flexion. The average external rotation deformity with the hip in extension was 60 degrees, which worsened to 90 degrees during hip flexion. Three of these hips had been previously treated with in situ pinning for SUFE. Other hips were in patients who were either skeletally mature or close to skeletal maturity. We found that all were “profunda hips” with severe acetabular retroversion. The abnormality in acetabular version was best defined on axial imaging.

Conclusions: The femoral head is a spherical conchoid. The concept of version of the hip (both femoral and acetabular) as described by McKibbin, Tonnis and Ganz is reviewed. Femoral retroversion is common in patients with SUFE, but the addition of acetabular retroversion makes these hips disproportionately symptomatic. This deformity causes a combination of pincer and cam impingement, which is responsible for the marked disability. SUFE alone causes cam impingement, whilst a corresponding degree of slip without retroversion and profunda of the acetabulum is not that disabling.

Introduction: Leg length discrepancy (LLD) following total hip replacement (THR) is not uncommon. Some patients are symptomatic, with problems such as gait imbalance or back pain. LLD is a potential cause of litigation following THR.

We have observed that some patients perceive their LLD to be much greater than the true LLD. A large LLD is sometimes reported by therapists, despite only a small true LLD.

We have found that abduction tightness is a potent cause of apparent LLD, and report our investigations into this phenomenon.

Method: We have identified a series of patients with abductor tightness and a significant apparent LLD. The LLD becomes apparent when the operated leg is adducted to the midline (or when the patient stands with their ankles together). This causes the contralateral pelvis to elevate and the un-operated leg to “shorten”.

Clinical photographs and videos have been produced to demonstrate this phenomenon.

A 2-dimensional model has been made to demonstrate how the degree of abduction, offset and over-lengthening affect this phenomenon.

A computer model has been used to quantify these effects.

Results: An abduction contracture after THR will cause the un-operated leg to be apparently and functionally short, even in the absence of a true discrepancy.

Even with only minor abductor tightness, increasing the true length will disproportionately increase the apparent LLD.

Conclusion: An abduction contracture is a potent cause of apparent LLD. Even a small degree of true over lengthening will be greatly magnified by this phenomenon. We recommend careful clinical assessment for abductor tightness when examining patients complaining of a LLD after THR.

The purpose of this study was to establish the a)feasibility, b) reproducibility of spinal Quantec scans (a non-intrusive surface topography system) and c) the validity of the Quantec Q-angle against Cobb angles from spinal radiographs, in non-ambulant children with cerebral palsy (CP).

Eighteen non-ambulant children (aged 5–11 years) with CP had successful clinical, radiological and Quantec assessment of their spine while seated in a supportive seating system.

Scoliosis incidence was 72%, Cobb angles ranged from 1–73° (mean 18.2°). Quantec scanning was feasible with appropriate postural support. Mean interobserver differences were 0.5 ± 5.8° (median 1.3°, 5 / 95th percentiles lying at −7.3 / 8.5° respectively). Mean differences between Cobb and Q-angle were 0.02 ± 6.2° (median 1.0°, with 5 / 95th percentiles lying at −8.2 / 7.7° respectively).

Surface topography may be used to safely monitor the spine for non-ambulant CP children. Results show similar or improved trends to previous comparisons with idiopathic scoliosis. Ovadia (2007) showed an interobserver mean difference of 6.3 ± 4.9° using an Ortelius800TM system. Thometz (2000) showed mean differences between Cobb and Q-angle ranging from 1.1–12.6 ± 4.9–10.2°. Further research is needed for the user group described in this study with larger spinal curves.

Ethics approval: Ethics approval granted by Leeds (West) Research Ethics Committee

COREC number: 08/H1307/22

Interest Statement: None

Introduction: Despite the satisfactory short-term implant survivorship of MoM hip resurfacing arthroplasty, symptomatic abnormal periprosthetic soft-tissue masses relating to the hip joint, ‘pseudotumours’, are being increasingly reported. These were found be locally destructive, requiring revision surgery in 75% of patients. Asymptomatic pseudotumours have not been previously investigated.

Methods: The aims were: (1) to investigate the prevalence of asymptomatic pseudotumours; and (2) to investigate their potential association with the level of metal ions. A total of 160 hips in 123 patients with a mean age 56 years (range 33–73) were evaluated at a mean follow-up of 61 months (range 13–88). Radiographs and OHS were assessed. Patients with a cystic or solid mass detected on the ultrasound/MRI had an aspiration or biopsy performed. Cobalt and chromium levels were analysed using Inductively-Coupled Plasma Spectrometer.

Results: Pseudotumours were found in 6 patients (5F: 1M). In 80% of bilateral cases, it was found in both sides. Histological examination showed extensive necrosis and diffuse lymphocyte infiltration. The presence of pseudotumour was associated with higher serum cobalt (9.2 μg/L vs. 1.9μg/L, p< 0.001) and chromium levels (12.0μg/L vs. 2.1μg/L, p< 0.001); higher hip aspirate cobalt (1182 μg/L vs. 86.2μg/L, p=0.003) and chromium levels (883μg/L vs. 114.8μg/L, p=0.006); and with inferior OHS (23 vs. 14 p=0.08).

Discussion: The prevalence of asymptomatic pseudotumour (5%) was higher than previously reported for the symptomatic pseudotumours (1%). There was a sixfold elevation of serum and a twelve-fold elevation of hip aspirate levels of cobalt and chromium in patients with pseudotumours. This suggests that pseudotumours may be a biological consequence of the large amount of metal debris generated in vivo. The association between pseudotumour and elevated metal ion levels might theoretically be explained by either systemic hypersensitivity responses to metal ions or local cytotoxic effects due to a high level of metal ions.

This study aims to evaluate the accuracy of sheer off self limiting screw drivers and to assess repeatability with age.

It has been reported that overzealous tightening of halo pins is associated with co-morbidity. Our unit has recently received a tertiary referral where the patient over tightened a pin leading to intracranial haematoma, hence our interest in this subject. The torque produced by six new and nine old screw drivers was tested using an Avery Torque Gauge and a Picotech data recorder. These devices are designed to produce a torque of 0.68 Nm, any greater than this is potentially hazardous. Accepted error for each device was +/− 10%. The average torque produced by the new screw drivers was 0.56 Nm with a range of 0.35–0.64 Nm (SD 0.120). The older screw drivers produced an average torque of 0.67 Nm ranging from 0.52–0.85 Nm (SD 0.123).

In conclusion, sheer off self limiting screw drivers are not accurate devices. The older devices are more likely to produce a torque exceeding a safe range and therefore we would recommend the use of new devices only.

Ethics approval: none audit.

Interest statement: none local grant.

Introduction: One of the main factors in the success of impaction bone grafting (IBG) in revision hip surgery is its ability to resist shear and to form a stable construct. Bone marrow contains multipotent skeletal stem cells and we propose that in combination with allograft will produce a living composite with biological and mechanical potential. In this study we looked at whether coating of the allograft with type 1 collagen followed by seeding with human bone marrow stromal cells (hBMSC) would enhance the grafts mechanical and biological properties.

Methods: A control group of plain allograft and three experimental groups where used to determine the effects that collagen and hBMSC have on IBG. The samples where impacted in standardised fashion previously validated to replicate femoral IBG, and cultured in vitro for 2 weeks. The samples then underwent mechanical shear testing and biochemical analysis for DNA content and Osteogenic activity.

Results: In isolation, both Collagen coating and seeding with hBMSC significantly enhanced the mechanical properties of the construct compared to the ‘gold standard’ of plain allograft. This was further enhanced (p=0.002) when the two processes are combined both with shear strength (245 vs. 299 kPa) and cohesion between the graft particles (46 vs. 144 kPa). The collagen coated group also showed increased osteogenic cell proliferation.

Discussion: This study has shown a role in the improvement of the mechanical properties of IBG coated with collagen and seeded with hBMSC. Collagen coating of IBG is a simple process and translation of the technique into the theatre setting feasible. The improvement in shear strength and cohesion could lead to earlier weight bearing for the patients and allow quicker recovery. The therapeutic implications of such composites auger well for orthopaedic applications. We are currently strengthening the above findings with an in vivo study.

Purpose of the study: We report an unusual complication of patella tendon rupture that occurred secondary to the use of static cement spacer blocks in a series of three patients undergoing staged revision total knee arthroplasty (TKA) for infection.

Methods and results: 3 male patients developed patella tendon injury secondary to anterior subluxation of static cement spacer blocks used at the first of a two-stage revision procedure for infected TKA. Average patient age was 70 years. The interval between the 1st and the 2nd stages varied between 3.5 to 24 months. At the second stage, it was observed that the patella tendon was completely severed and irreparable in one case, whereas it was partially injured and repairable in the other two cases. In the case with irreparable tendon injury, stable joint reconstruction could not be achieved at the second stage and ultimately resulted in knee arthrodesis. In the other two cases, 2nd stage revision was performed using hinged revision knee components and the tendon injury was repaired and protected with a circlage wire. None of the patients were satisfied with their outcome at the final review.

Conclusion: This is the first report in the literature reporting the complication of patella tendon rupture secondary to the use of static cement spacer blocks in staged revision knee arthroplasty. The injury can either be repairable or irreparable. The functional outcome and satisfaction is not good after the salvage procedures. Therefore, we recommend that these spacer blocks should not be used in revision knee arthroplasty.

Introduction: Inaccuracies in kinematic data recording due to skin movement artefact are inherent with motion analysis. Image registration techniques have been used extensively to measure joint kinematics more accurately. The aim of this study was to assess the feasibility of using MRI for creating 3D models and to quantify errors in data collection methods by comparing kinematics computed from motion analysis and image registration.

Methodology : 5 healthy and 5 TKR knees were examined for a step up/down task using dynamic fluoroscopy and motion capture. MRI scans of the knee, femur and tibia were performed on the healthy subjects and were subsequently segmented using ScanIP(Simpleware) to produce 3D bone models. Registration of the models produced from fine and coarse scan data was used to produce bony axes for the femoral and tibial models. Tibial and femoral component CAD models were obtained for the TKR patients. The 3D knee solid models and the TKR CAD models were then registered to a series of frames from the 2D fluoroscopic image data (Figure 1) obtained for the 10 subjects, using KneeTrack(S. Banks, Florida) to produce kinematic waveforms. The same subjects were also recorded whilst performing the same action, using a Qualisys (Sweden) motion capture system with a pointer and marker cluster-based technique developed to quantify the knee kinematics.

Results: The motion analysis method measured significantly larger frontal and transverse knee rotations and significantly larger translations than the image registration method.

Conclusion: The study demonstrated that MRI, rather than CT scan, can be used as a non-invasive tool for developing segmented 3D bone models, thus avoiding highly invasive CT scanning on healthy volunteers. It describes an application of combining fine and coarse scan models to establish anatomical or mechanical axes within the bones for use with kinematic modeling software. It also demonstrates a method to investigate errors associated with measuring knee kinematics.

Background: It remains unclear and controversial whether preoperative magnetic resonance imaging (MRI) in patients with adolescent idiopathic scoliosis (AIS) should be mandatory.

Aim: (1) To review our own practice, (2) conduct a national survey of United Kingdom Consultants, and (3) to perform a literature review.

Methods: Our own practice was established by identifying patients with AIS and examining whether an MRI scan was performed preoperatively. A survey of Consultants practice in the UK (British Scoliosis Members) was conducted by either an e-mail or telephone conversation. Finally, a literature survey was performed to establish current views.

Results: 118 patients with AIS were identified between 2003 and 2007. 78% of these patients underwent pre-operative MRI scans. Neural axis abnormalities were found in 8% of these patients. They included syrinx’s, chiari malformations, tonsillar herniation, cord tethering, central canal dilatation and undiagnosed spina bifida. Only 1 patient required intervention by the neurosurgeons. 92% of respondents to the national survey routinely performed preoperative MRI scans. The literature was not conclusive with regards to mandatory preoperative imaging.

Conclusion: Despite the literature showing little evidence, our survey shows a widespread consensus in clinical practice across the UK that routine preoperative MRI should be performed from a risk management viewpoint. It is mandatory in our unit to perform pre-operative MRI scans on all patients with AIS and would recommend that this becomes standard practice in all other units.

Ethics Approval: None/Audit

Interest Statement: None

The purpose was to develop an objective measurement system to assist in the prescription of supportive seating for non-ambulant cerebral palsy children with scoliosis.

Currently the prescription of patient’s bespoke seating setup relies on clinical skills and knowledge of trained seating staff (physiotherapists and engineers). Therefore to develop an objective measurement system to supplement this clinical approach, a user centred design approach was used.

Standard design processes presented in Pahl’s ‘Engineering Design’ (2007) were adopted, allowing in depth user involvement. Stakeholders (clinical, seating, and technical staff) were interviewed to develop requirements lists for each group. Following each development stage; task clarification; concepts; embodiment; detailed design; manufacture; and commissioning, these requirements were reviewed with stakeholders.

Requirements lists were collated to form the device specification, involving all stakeholders allowed the discussion of contradicting requirements. The final design incorporated critical aspects of seating while measuring important outcomes such as force distribution and spinal deformities.

A user centred design approach allowed for informative decision making from stakeholders, highlighting the fundamental requirements and facilitated effective solutions to meet these requirements.

The manufactured device complies with the collaborated specification, utilising stakeholder defined spinal and seating parameters. This was commissioned for use in a pilot study involving twenty non-ambulant cerebral palsy children aged 5–11 years, with high risk of scoliosis.

Ethics approval: Ethics approval granted by Leeds (West) Research Ethics Committee

COREC number: 08/H1307/22

Interest Statement: None

Aim: To assess the outcome of knee arthrodesis using cemented Endo-Model knee fusion nail in failed total knee arthroplasty with significant bone loss due to infection.

Methods: A Retrospective case study of seven patients with infected TKR and multiple surgeries and significant bone loss (Type III AORI classification). All patients had antibiotic loaded cement with a temporary K-nail as a first stage procedure to eradicate infection. All seven patients had arthrodesis performed using cemented modular Endo-Model Knee Fusion nail (Waldemar Link, Hamburg) by senior author (RSJ). The arthrodesis relied on the strong coupling mechanism of the nail and not on bony union, providing pain relief while mainting leg length. Outcomes assessed using pre–and post Visual Analogue Score (VAS) and Oxford knee scores.

Results: Mean age 76.8 years (62–85). Mean follow up 23.7 months (3–42). The mean VAS pain score improved from 7.6 (6.5–8.5) pre-operatively to 1.1 (0–3.2) post-operatively. The mean post-operative Oxford score was 30.3 (27–36). One patient required revision for asceptic loosening. All but one of the patients thought that arthrodesis was preferable to amputation post-operatively.

Conclusion: The Endo-Model knee fusion nail has good early results in terms of pain relief and knee arthrodesis where there is significant bone loss and extensor mechanism insufficiency following an infected total knee replacement.

Purpose: Waterproof casts have been shown to be a safe and effective means of immobilization in children with minimally displaced fractures. The purpose of this study was to determine if waterproof Gore-Tex-lined casts are as effective as traditional cotton-lined casts in the immediate postoperative period after closed reduction of displaced distal radius fractures in children.

Method: We performed a retrospective review of distal radius fractures that underwent closed reduction and application of a long-arm cast between June 2004 and December 2006. A total of 124 cases were included (55 Gore-Tex; 69 traditional cotton-lined). The primary outcome measure was redisplacement in the cast. The cast index was also used to assess the quality of cast molding. Data was analyzed using repeated measures ANOVA. Power analyses were also conducted.

Results: There were no significant differences between the two groups with regards to translation of the radius or angulation of the radius on anterior-posterior (AP) and lateral radiographs at the time of injury, postreduction, or cast removal. Redisplacement as measured by the change in translation of the radius and angulation of the radius on AP and lateral radiographs from the time of reduction to cast removal was also not significantly different between the two groups. The mean cast index for the Gore-Tex and traditional cotton-lined groups was 0.882 and 0.873 respectively, which was not a significant difference.

Conclusion: A waterproof Gore-Tex-lined cast will maintain fracture reduction as well as a cotton-lined cast for closed reductions of distal radius fractures in children in the immediate postreduction period. Waterproof casts also provide extensive benefits to the patient with regards to bathing, hygiene, and participation in aquatic activities

Introduction: The Ionising Radiations Medical Exposure Regulations Act 2000 has established diagnostic reference levels for radiological examinations, however at present there are no national guidelines available for orthopaedic trauma surgery. There may be a role for the introduction of diagnostic reference levels at a local level therefore we studied patient area dose and screening time for orthopaedic trauma operations performed in the Regional Trauma Centre in Northern Ireland.

Methods: Retrospectively data was retrieved from written radiography records in the Royal Victoria Hospital, during the period of 1st January 2007 to 31st December 2007 for all orthopaedic trauma cases in which an image intensifier was used. The screening time, patient area dose (PAD), details of the operation, patient age, sex, month of the operation and grade of the operating surgeon (trainee or consultant), were recorded.

Results: 1709 cases using image intensifier were reviewed. 137 cases were excluded due to incomplete data. 319 hips were screened for insertion of sliding hip screw, mean screening time was 0.51min with a mean PAD of 145cGycm2. 127 femoral nails were inserted with an average screening time of 1.84min and mean PAD of 310 cGycm2. 166 tibias were screened for application of Ilizarov frame or insertion of tibial nail, average screening time was 3.00min with a mean PAD of 48cGycm2. 129 spinal cases were screened with an average screening time of 0.80mins and mean PAD of 37.9cGycm2. Consultants had lower screening times and mean PADs than trainees with 0.63min versus 1.01min and 65.8cGycm2 versus 70.9cGycm2.

Conclusions: The average screening times and mean PADs compared favourably with local reference guides for image intensifier cases and with other published series. Every trauma unit should have local reference ranges for orthopaedic imaging cases and regular audit should be carried out to assess compliance with these ranges.

In January 2000 we introduced identical guidelines for the more rapid rehabilitation of Achilles tendon ruptures, whether treated operatively or non-operatively. A relaxed equinus cast was used to four weeks, then a CAM walker to eight weeks with supervised mobilisation. The aims of this study were to compare the outcomes of the operative and non-operative groups treated with the same rehabilitation program and audit the effectiveness of these guidelines.

The audit was retrospective from January 2000 till January 2008. The patients were identified from the Emergency Department admissions database, the hospital clinical coding system, the department’s surgical audit data and the hospital physiotherapy appointment system. The audit system was used to identify patients that had complications of their operative treatment, re-ruptures or readmissions. This study focused on the end points of re-rupture, readmission, complications including wound complications and infection.

Five hundred and eighty seven presentations were recorded as Achilles tendon injuries. One hundred and eighty patients were treated operatively and 407 patients were treated conservatively. Seventy five patients (42%) treated operatively and 126 patients (30%) of the non-operative group were rehabilitated in our hospital physiotherapy department. The remaining 386 patients (65.7% of all patients) received physiotherapy elsewhere or did not attend for further treatment. In the operative group there were two re-ruptures (1.1%) both treated in our hospital physiotherapy department. There were 2 wound complications (1.1%), one requiring re-operation. In the non operative group there were 15 re-ruptures (3.7%). Of these three had attended the hospital physiotherapy department (rerupture rate of 2.4%) In the non-operative group treated elsewhere there were 12 re-ruptures from 281 patients (4.2%).

Comparable results were found between operative and non-operative treatment when combined with close physiotherapy guidance. Non-operatively treated patients treated in the community may have higher re-rupture rates. The results are comparable to those in the literature suggesting that the guidelines are effective.

The presence of pseudotumours, which are soft-tissue masses relating to the hip, after metal-on-metal hip resurfacing arthroplasty has been associated with elevated levels of metal ions in serum, suggesting that pseudotumours occur when there is increased wear. We aimed to quantify the wear in vivo of implants revised for pseudotumours (eight) and of a control group of implants (22) revised for other reasons of failure.

We found that the implant group with pseudotumours had a significantly higher rate of median linear wear of the femoral component at 8.1 μm/year (2.75 to 25.4) than the 1.79 μm/year (0.82 to 4.15; p = 0.002) of the non-pseudotumour group. For the acetabular component a significantly higher rate of median linear wear of 7.36 μm/year (1.61 to 24.9) was observed in the pseudotumour group compared with 1.28 μm/year (0.81 to 3.33, p = 0.001) in the other group. Wear of the acetabular component in the pseudotumour group always involved the edge of the implant, indicating that edge-loading had occurred.

Our findings are the first direct evidence that pseudotumour is associated with increased wear at the metal-on-metal articulation. Furthermore, edge-loading with the loss of fluid-film lubrication may be an important mechanism of generation of wear in patients with a pseudotumour.

Current opinion is divided as to whether carpal tunnel syndrome requiring operative decompression can be caused by an occupation.

The aims of this study were to define the lamb freezing worker population who acquire carpal tunnel syndrome and to confirm or refute lamb boning as an occupational cause for carpal tunnel syndrome.

Roles, gender age and exposure periods of all workers who had carpal tunnel decompressions over the past six seasons at the largest lamb Freezing Works in the world were examined. Kaplan-Meier survival analysis for boners, slaughter men and non-knife labourers was performed and tested for significance. Chi-square analysis and ANOVA were performed for gender and age. Age and gender-adjusted Cox regression analysis was performed to establish relative risks/hazard ratios for each of the three groups developing carpal tunnel syndrome. Incidences for boners and non-knife hands were calculated. Comparison of this population and a standard carpal tunnel population was performed.

Two hundred and eighty five carpal tunnel decompressions were performed in workers who failed conservative management at the largest lamb freezing works in the world by a single surgeon after neurophyiological-test confirmation of the diagnosis. Of those having surgery 79% were men: 21% female and this was significant with Chi square testing (p< 0.01). At decompression boners were significantly younger than non-knife hands (p< 0.01). Adjusting for age and gender boners were 120% more likely to need decompression than non-knife labourers (p< 0.01). The median survival for a lamb boner’s carpal tunnel at five years was 44%. The incidence of carpal tunnel syndrome in lamb boners was 10% (person-seasons). This population is entirely different to the published idiopathic population requiring carpal tunnel decompression which is predominantly female with meanage of 55.

To our knowledge this is the first study to provide sound evidence that carpal tunnel syndrome can be caused by an occupation. We have quantified this and welcome ideas for further work in this fascinating a uniquely New Zealand population.

Purpose: Simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction has been proposed as a treatment for patients with combined medial compartment knee osteoarthritis (OA) and ACL deficiency. Although goals of surgery are to correct malalignment, decrease knee joint load and enable continued participation in sports, few prospective studies evaluating these outcomes exist. Therefore, the objective of this study was to evaluate two-year changes in frontal plane alignment, dynamic knee joint load and self-reported function during sport after simultaneous HTO and ACL reconstruction.

Method: Thirty patients with varus alignment, medial compartment knee OA and ACL deficiency have undergone medial opening wedge HTO and hamstring tendon ACL reconstruction during a single operation. Full-length, standing AP radiographs (mechanical axis angle), dynamic knee joint loads (the peak external adduction moment about the knee during self-paced walking) and the Knee Injury and Osteoarthritis Outcome Scale (KOOS) were completed before and 24 months after surgery.

Results: Based on the 14 patients currently at 24.9 ± 1.67 months postop (12 males; age = 38.5 ± 7.5 yrs.; BMI = 29.5 ± 5.6, median Kellgren and Lawrence grade = 2), mechanical axis angle decreased significantly (p< 0.005) from −6.2 ± 3.63° to 0.29±1.94°. Despite a small (0.06 ± 0.10m/s), but significant (p< 0.05), increase in self-paced walking speed after surgery, the peak knee adduction moment decreased significantly (p < 0.001) from 2.96 ± 0.61 %BW*ht to 1.58 ± 0.48 %BW*ht [mean decrease = 1.38 %BW*ht (95% CI: 0.87 – 1.89)]. Each domain of the KOOS also improved significantly (p< 0.05), with the mean sports and recreation domain increasing (p=0.001) from 26.92 ± 24.29 to 66.54 ± 28.09 [mean increase = 39.62 (95% CI: 20.09 – 51.14)]. Data from 30 patients will be available at time of presentation.

Conclusion: Two-year outcomes after simultaneous medial opening wedge HTO and ACL reconstruction suggest this treatment results in substantial improvements in alignment, knee joint load and self-reported functioning during sport.

Purpose: To evaluate the functional outcome of operatively treated Lisfranc injuries.

Method: Over a 7-year interval from 1998 to 2005, 184 skeletally mature patients were identified retrospectively with operatively treated Lisfranc injuries. 85 patients had prospectively measured SMFA functional outcomes and satisfaction surveys. The gender was 37 males and 48 females. Mean age was 39 years (range 17–93).

Results: The mechanism was fall (31), MVA (24), crush (15), equestrian (5), or twisting (10). Patients were operatively treated with open reduction internal fixation (ORIF, 53) or primary arthrodesis (PA, 32). The SMFA reliability for this patient sample was 0.892. The function and bother outcomes were 19.4 and 15.8, respectively. The function (21.5 vs. 16.0, p=.11) and bother (17.5 vs. 13.0, p=.25) outcomes were not significantly different for ORIF vs. PA, respectively. In the ORIF group, HW removal (40 of 53) performed better than HW retention (13 of 53) with outcome bother but not function measures of (14.7 vs. 26.1, p< 0.05).

Conclusion: If performed well, either ORIF or PA technique function well. Patients are more satisfied with the results and appearance of PA over ORIF. HW removal compared to HW retention positively affect bother not function measures. Secondary surgeries negatively affect both bother and function measures. Patients with pain, associated foot or polytrauma injuries function worse.

Calcium and vitamin D are both of key importance for bone health, and their effects on bone appear to begin even in utero and continue throughout life. The dietary requirements for both calcium and vitamin D are different at different stages of the lifespan. Importantly, in Australia the bulk of vitamin D comes from manufacture of vitamin D in the skin from ultraviolet light exposure i.e. from sun exposure, as the amount of vitamin D in foods is low. Vitamin D deficiency is common at all stages of life and some groups are at particularly high risk. Adequate calcium intake and maintaining adequate vitamin D levels are important in childhood for maximising peak bone mass, but the effect of calcium supplementation on bone mineral density is small. The role of vitamin D supplementation in childhood outside of treating rickets is unclear, though there is potential for a clinically significant effect. Calcium and vitamin D supplements have been investigated for the primary prevention of osteoporotic fracture in the elderly. Calcium and vitamin D is effective at reducing non-vertebral and vertebral fractures in the institutionalised elderly but community-based studies show conflicting results. There is no evidence that calcium, vitamin D or the combination of calcium and vitamin D alone prevent fractures in those who have already sustained a low trauma fracture (secondary prevention) but calcium and vitamin D are both important adjunctive treatments in established osteoporosis i.e. in combination with other pharmacotherapies.

Purpose: Pediatric femoral fracture treatment is varied. Each treatment has advantages and disadvantages. The goal of treatment is to avoid complications, reduce costs, and return function. Percutaneous bridge plating has many advantages and little disadvantages. The purpose of this study was to examine the results of percutaneous bridge plating for pediatric femoral diaphyseal fractures.

Method: Over a 4-year time span (2002–2005), all pediatric femoral fractures were diagnosed. A retrospective chart review was completed and only percutaneous bridge plating treatment was analyzed.

Results: 78 fractures were noted in 73 patients. Average age was 9 (range 3–16). Gender was 56 males and 22 females. Most common mechanisms were falls 15 (19%), MVA 12 (15%), and pedestrians 9 (12%). Four fractures (5%) were open. Forty-three fractures (61%) were associated with polytrauma. Time to operation averaged 1 day (0–11 days, 89% 0–1 day). Most plates were 3.5 combi locked plates with a lesser but equal number of 3.5 DCP and 4.5 DCP. Length of stay averaged 5 days (range 0–45 days, 18% 0–1 day, 58% 2–4 days). The majority of patients (58%) began weight bearing at 2–6 weeks. Callus formation began at 2–6 wks (84%). Fracture healing occurred by 6 weeks in 91%. Limp was resolved by 3 months in 54%. Pain was resolved by 3 months in 90%. Patients were back to active daily living without restrictions by 3 months in 96% of the fractures. Complications were noted with 4 superficial wounds, 4 problematic scars, 3 leg overgrowth < 12 mm, and 3 distal prominent plates. No nonunions or refractures were noted. Hardware (HW) was removed on average by 6 months (range 3 mo to never). Outpatient percutaneous HW removal was performed in 100% of the cases.

Conclusion: Percutaneous bridge plating for pediatric femoral fractures is predictable and effective with minimal complications. Asymptomatic femoral overgrowth was minimal.

The use of MRI scanning has been described after open reduction of the hip in DDH to check hip position but has not previously been reported after open reduction with femoral osteotomy and the use of metalwork. We performed a prospective study utilising MRI to document the adequacy of reduction.

An MRI scan was performed on the second postoperative day in order to confirm the satisfactory reduction of the hip following surgery. Previously a CT scan was performed.

10 consecutive cases were scanned and all gave diagnostic information of satisfactory reduction. Sedation was not required. The mean scanning time was 3 minute 45 seconds and the total time in the MRI suite ranged from 7 to 10 minutes.

Satisfactory images, the lack of need of sedation, comparable time and cost to CT scanning and most importantly the lack of exposure of the child to ionising radiation make MRI a most appealing method of imaging. We therefore recommend it as the investigation of choice in this patient group.

Demographic data reviewed included gender, MP at time of primary surgery, GMFCS level, age at time of surgery, type of adductor release procedure performed, and experience of surgeon.

Outcome variables assessed were type of subsequent failure, time of failure after primary procedure, and length of follow-up.

Three hundred and thirty children underwent hip adductor surgery. The number of children per GMFCS Level was 33 Level II, 55 level III, 103 level IV, and 139 level V. The average age at time of primary surgery was 4.19 years, mean MP at time of primary surgery 43.16%, and mean length of post-operative follow-up was 7.10 years.

Eighty two children had adductor longus and gracilis lengthening alone, 97 also had an iliopsoas release, 97 had psoas tenotomy and phenolisation of the obturator nerve, and 54 had a psoas tenotomy and neurectomy of the anterior branch of the obturator nerve (in addition to longus & gracilis lengthening).

At time of audit 106 children did not require further surgery (‘surgery success’ of 32%). Thirty one were in children of GMFCS level II (94%), 27 level III (49%), 28 level IV (27%), and 20 level V (14%).

A Cox proportional hazards survivorship analysis was constructed to chart the time course of progression to further surgery over time to reveal statistically significant ‘surgery success’ rates according to GMFCS. Differences in the success rates according to GMFCS become more apparent beyond 3 years post-surgery.

The most important determinant for predicting the success of hip adductor surgery in preventing hip displacement is GMFCS at the time of primary surgery. Current treatment strategies need to be re-evaluated with the context of undertaking long-term post-operative follow up, particularly for children GMFCS levels VI and V.

Purpose: Many lateral malleolar fractures in patients with osteoporotic bone are rotationally unstable, requiring fixation stable in torsion with good fatigue properties, but without bulk due to the soft tissue constraints. The purpose of this study was to evaluate the torsional performance of a thin (1.5mm) plate with locked and non-locked constructs in a simulated osteoporotic lateral malleolus fracture.

Method: A transverse fracture gap to mimic comminution was created in (15 lb/ft3) density foam. 3 bicortical unlocked screws were used proximal to the fracture in a 5 hole thin (1.5mm) plate for both constructs. Distally, two screws that did not breach the far cortex (12mm) were placed as locked in one group and unlocked in the other. The constructs were loaded in torsion at 1 Hz at 7.5/0.75 in-lbf (0.85/0.08 N-m) of torque. A torsional fatigue failure was defined as either a fracture of the plate, screw pull-out, or construct rotation 10 degrees beyond the maximum initial rotational displacement. Testing was conducted until construct failure or run-out of 300,000 cycles.

Results: The thin plate constructs with locked distal screws showed significantly improved fatigue properties (p< 0.00001). None of the locking plate constructs failed prior to the 300,000 cycle end point. In stark contradistinction, all of the non-locked contructs failed at an average cycle count of only 9,541 (range 1,000 – 23,000 cycles). The failure mode for each of the non-locked constructs was pull-out of the distal screws.

Conclusion: These results indicate that the use of a thin plate with locking capability provides a significant advantage over non-locked constructs in fatigue performance in areas of poor bone density subjected to torsional loads, such as the lateral malleolus.

Metal-on-metal hip resurfacing is commonly performed for osteoarthritis in young active patients. We have observed cystic or solid masses, which we have called inflammatory pseudotumours, arising around these devices. They may cause soft-tissue destruction with severe symptoms and a poor outcome after revision surgery. The aim of this study was to determine the incidence of and risk factors for pseudotumours that are serious enough to require revision surgery.

Since 1999, 1419 metal-on-metal hip resurfacings have been implanted by our group in 1224 patients; 1.8% of the patients had a revision for pseudotumour. In this series the Kaplan-Meier cumulative revision rate for pseudotumour increased progressively with time. At eight years, in all patients, it was 4% (95% confidence interval (CI) 2.2 to 5.8). Factors significantly associated with an increase in revision rate were female gender (p < 0.001), age under 40 (p = 0.003), small components (p = 0.003), and dysplasia (p = 0.019), whereas implant type was not (p = 0.156). These factors were inter-related, however, and on fitting a Cox proportional hazard model only gender (p = 0.002) and age (p = 0.024) had a significant independent influence on revision rate; size nearly reached significance (p = 0.08). Subdividing the cohort according to significant factors, we found that the revision rate for pseudotumours in men was 0.5% (95% CI 0 to 1.1) at eight years wheras in women over 40 years old it was 6% (95% CI 2.3 to 10.1) at eight years and in women under 40 years it was 13.1% at six years (95% CI 0 to 27) (p < 0.001).

We recommend that resurfacings are undertaken with caution in women, particularly those under 40 years of age but they remain a good option in young men. Further work is required to understand the aetiology of pseudotumours so that this complication can be avoided.

Purpose: Recent animal evidence has suggested that Bupivicaine may be harmful to articular cartilage. The purpose of this study was establish whether, following arthroscopy of the knee, infiltration of Bupivicaine around the portals is as effective as intra-articular infiltration for post-operative analgesia.

Method: Consecutive patients attending for knee arthroscopy were consented and randomised to one of two groups. Following arthroscopy, Group I received 20mls 0.5% Bupivicaine infiltrated into the joint; Group II received 20mls 0.5% Bupivicaine infiltrated around the portals. A Visual Analogue Score (VAS) was collected at one hour post-operatively and rescue analgesia recorded. A power calculation was performed. Ethical approval was granted.

Results: There were 68 patients in Group I (intra-articular) and 69 patients in Group II (portal). There was no significant difference in the age or sex distribution of patients in either group. The mean VAS score was 3.04 in Group I and 3.24 in Group II. There was no significant difference between the two groups (p=0.619). There was also no significant difference in the need for rescue analgesia (p=0.930). The study has demonstrated equivalence between the two groups, within one VAS point (Power = 80%).

Conclusion: We would recommend that following knee arthroscopy, Bupivicaine should be infiltrated around the portals, avoiding intra-articular infiltration.

In a high-risk technically advanced speciality like spine surgery, detailed information about all aspects of possible complications could be frightening for the patients, and thereby increase anxiety and distress. Therefore, aim of this study was to

Analyze written evidence of the consenting procedure pertaining to (a) nature of operation (b) benefits intended as a result of the operation (c) risks specific to the particular type of operation (c) general risks of spine surgery and anaestheia.

Methods: 70 adult elective, consecutive patients who had been listed for Lumbar discectomy /decompression surgery were chosen. The patients were presented with questionnaire of broad-based and open-ended questions designed to elicit theirs views in each of the following areas: expectation, knowledge of risks and alternatives, and personal attitude to information and satisfaction.

The study had a non-randomized design and patients divided into TWO groups Group A and group B.

The patients in the group A received standard information and were consented in a routine way without being given written proforma with all complications. The patients in the group B were given the same information as patients in the control group, with written information about common and rare complications. Patients in both groups were assessed on an ‘impact of events scale’ and hospital anxiety and depression scale immediately before ad after the consent process and again after surgery when they were discharged from the hospital.

For comparison of the proportion of Yes and No answers in 2 groups, Fisher’s exact test was used, and for comparison of more than 2 groups, the Chi-square test was used. For graded answers and other ordinal scales, the Mann–Whitney U-test was used for comparison of 2 groups and the Kruskal–Wallis test for comparison of more than 2 groups. Spearman’s test was used when assessing the correlation between 2 variables measured on an ordinal scale.

Results: Many patients (71%) agreed that the consent form made clear what was going to happen to them, and 77%) reported that it made them aware of the risks of the operation they were to undergo. Over a third (36%) saw it as a safeguard against mixups in the operating theatre. Few patients’ decision to accept surgery appeared to depend on risk information; 8% of patients said that they might have changed their decision, had they been advised of the risks of permanent stroke and myocardial infarction. However, 92% were clear that their decision to accept treatment would not have altered. The women in the group B had symptoms of definite anxiety to a significantly higher degree than the men before the operation. Post-operatively, patients receiving extended information were significantly more satisfied with both the written and oral information about common and rare complications than patients in the control group There were no statistically significant differences between the groups for anxiety or depression, as measured by the HADS, either before or after the operation between Group A and B. Provision of extended information describing most of the possible complications did not have any negative effects on the patients. The patients receiving the extended information were more satisfied and experienced to a higher degree that they could discuss alternative treatment methods with the surgeon. Discussion: Provision of extended information describing most of the possible complications did not have any negative effects on the patients. “Ignorance is bliss” may prove to be an excellent preoperative strategy for patients when outcome is good but detrimental to long term adjustment where significant postoperative complications arise. This raises the possibility that a separate consent could be used where these risks are pre-printed and explained in vocabulary easily understood by patients. The added advantages of this form would be less confusion for the patient and there would be written evidence that patients had understood each of the major risks involved with the proposed procedure. This proposed consent form would also reduce the chance that important risks and complications are omitted when consent is being taken, as well as tackling the issue of variability of experience or lack of knowledge by the person obtaining consent.

Aim: To determine the clinical improvement and the radiological time to fusion as well as correction of the lordosis angle in patients undergoing anterior cervical interbody fusion with the use of a silicate substituted calcium phosphate ceramic (Si-CaP) (Actifuse™ Synthetic Bone Graft, ApaTech, Ltd., Elstree, UK) as the bone graft substitute in the cage.

Design: We conducted a prospective clinical and radiological study to evaluate the use of Si-CaP as bone graft substitute in anterior cervical fusion for degenerative cervical spondylosis.

Materials and methods: Thirty patients were selected prospectively by preoperative and postoperative clinical and radiological assessments. All patients were operated on by a single surgeon (D.A.J.). Neck disability index and visual analogue score were used for the clinical assessment. Radiological assessment included improvement in the lordosis angle and time to fusion. Patients were evaluated at three months, six months and one year post-surgery.

Results: At present 14 patients with a total of 19 levels have completed their one year follow-up. The patients had an average of 50.4 years (range 34–69), with ratio of male to female of 6:7. Lordosis angle improved significantly from a mean lordosis angle of 0.31 preoperatively to 4.75 degree postoperatively (p< 0.05). All the levels had fused at the 1 year follow up and there was no radiological evidence of sinkage of the cage.

Conclusion: Substitution of silicate ions into calcium phosphate ceramics has been shown to impart a negative surface charge, leading to greater protein absorption, increased osteoblast proliferation, and higher production of extracellular matrix. Our results show that Si-CaP has excellent clinical performance as a synthetic bone graft in anterior cervical discectomy and fusion. Postoperatively, patients demonstrate a good fusion with an excellent correction and maintenance of the lordosis angle.

Most hospitals have introduced digital radiography (PACS) systems. Accurate pre-operative templating prior to hip arthroplasty requires precise information on the magnification of the digital image. Without this information the benefits of expensive digital templating programs (Orthoview-£10000) cannot be realised.

To determine the magnification of a digital image involves the placement of a “calibration object” at the level of the hip joint. This is unpopular with patients and radiographers alike. We describe a method that requires a single measurement to be made from the greater trochanter to the digital film.

An AP pelvis x-ray was taken of 50 patients with hip replacements. The “predicted” magnification was calculated using the new method. As the size of the head of the prosthesis was known the “actual” magnification could be calculated also. There was no significant difference at 0.05, Wilcoxon T, 2-tail test.

Conventional radiography, which assumes a magnification of 20%, results in errors up to 11%. Templating may therefore predict an incorrectly sized prosthesis. Our method is as accurate as methods using a calibration object whilst being acceptable to patients and staff. Its use should lead to more accurate pre-operative templating prior to total hip arthroplasty

Introduction: Scoliosis surgery involves major blood loss, at times exceeding estimated blood volume.

Aim: To evaluate the effects of implementing blood conservation strategies (including cell salvage, controlled hypotension and anti-fibrinolytic drugs) on transfusion requirements in adult patients undergoing scoliosis correction surgery. To establish a protocol for cross matching of blood.

Study Design: We retrospectively studied 50 consecutive adult patients who underwent scoliosis correction surgery (anterior, posterior or combined) between 2003 and 2007. All patients were anaesthetised by the same anaesthetist who implemented a standard transfusion protocol. Age, BMI, pre and post operative haemoglobin, levels fused, duration of surgery, hospital stay, antifibrinolytics used and blood transfused was noted.

Results: 50 patients with mean age 24.6 years and mean BMI 21.9 kg/m2 were studied. 14 patients had anterior surgery, 19 patients had posterior surgery and 17 had combined anterior and posterior procedures. Mean number of levels fused was 9.5 (6–15) and mean duration of surgery was 284.6 minutes (135–550 minutes). Anti-fibrinolytics were used in 31 patients (62%), Aprotinin in 21(42%) and Tranexamic acid in 10(20%). Mean blood loss in patients who received anti fibrinolytics was 530mls while mean blood loss in the other patients was 672mls. (p< 0.05). Blood transfusion was not required in any of the patients undergoing anterior correction only while 7 patients (41%) undergoing anterior and posterior correction and 3 patients (15.8%) undergoing posterior correction only required blood transfusion. Mean volume of cell saved blood re-transfused was 693.8 mls and mean hospital stay was 9.2 days. Mean pre-op haemoglobin was 13.2 g/dl (10.4–17.4) and mean post-op haemoglobin was 10.7 g/dl (7.7–15). 4 patients (8%) required intra and post-operative blood transfusion while 6 patients (12%) required blood transfusion postoperatively.

Conclusion: Use of anti-fibrinolytics like Aprotinin and Tranexamic acid reduces blood loss in scoliosis surgery. In the current scenario, with Aprotinin no longer available for use, our study would recommend the use of Tranexamic acid alongwith other blood conservation measures.

In our unit we do not have blood cross matched for anterior surgery alone.

Between December 2004 and June 2006, 136 patients (156 total hip replacements), were sent from the waiting list of the Cardiff Vale NHS Trust to the NHS Treatment Centre, Weston-super-Mare, in an attempt to reduce the waiting time for total hip replacement. Because of concerns about their outcome, each patient was contacted and invited to attend a review appointment with a consultant specialising in hip and revision hip replacement.

A total of 98 patients (113 hips) were reviewed after a mean of 23 months (11 to 30). There were 104 cemented hips, seven hybrid and two cementless. An acetabular inclination of > 55° was seen in 18 (16%). Radiolucent lines around the acetabular component were seen in 76 (67%). The femoral component was in more than 4° of varus in 47 (42%). The medial floor had been breached in 13 (12%) and there was a leg-length discrepancy of more than 1 cm in ten (9%). There were three dislocations, one femoral fracture, one pulmonary embolus, one deep infection and two superficial wound infections.

To date, 13% (15 hips) have been revised and a further 4% (five hips) await revision, mostly for a painful loose acetabular component. The revision rate far exceeds the 0.5% five-year failure rate reported in the Swedish Registry for the components used. This initiative and the consequent need for correction of the problems created, has significantly increased the workload of our unit.

Between November 1994 and June 1999, 35 patients referred to our Problem Fracture Service with chronic diaphyseal osteomyelitis were treated using a closed double-lumen suction irrigation system after reaming and arthroscopic debridement of the intramedullary canal. This is a modified system based on that of Lautenbach.

Between June and July 2007 the patients were reviewed by postal questionnaire and telephone and from the case notes. At a mean follow-up of 101 months (2 to 150), 26 had no evidence of recurrence and four had died from unrelated causes with no evidence of recurrent infection. One had been lost to follow-up at two months and was therefore excluded. Four had persisting problems with sinus discharge and one had his limb amputated for recurrent metaplastic change.

Our results represent a clearance of infection of 85.3% (29 of 34), with recurrence in 11.8% (4 of 34). They are comparable to the results of the Papineau and Belfast techniques, but with considerably less surgical insult to the patient.

Introduction: Sacroiliac joint (SIJ) is a diarthrodial joint and can often be a source of chronic low back pain complex. We present a percutaneous technique for SIJ fusion and the functional and radiological outcome following the arthrodesis.

Aims and Objectives: To evaluate the functional and radiological outcome following percutaneous technique for SIJ fusion with HMA (Hollow modular anchor-age) screws.

Materials and Methods: 15 consecutive patients operated for SIJ fusion between Sep 2004 and Aug 2007 were included in the study. The diagnosis was confirmed with MRI and diagnostic injections. Pre-operative and post-operative functional evaluation was performed using SF-36 questionnaire and Majeed’s scoring system. Postoperative radiological evaluation was performed using plain radiographs. The Hollow modular anchorage (HMA) screws (Aesculap Ltd, Tuttlingen) packed with bone substitute were implanted percutaneous under fluoroscopic guidance

Results: The study group included 11 females and 4 males with a mean age of 48.7 years. Mean follow-up was 14 months. Mean SF-36 scores improved from 37 to 80 for physical function and from 53 to 86 for general health. The differences were statistically significant (Wilcoxon signed rank test; p < 0.05). Majeed’s score improved from mean 37 preoperative to mean 79 postoperative. The difference was statistically significant (student t test, p< 0.05). 13 had good to excellent results. The remaining 2 patients had improvement in SF-36 from mean 29 to 48. Persisting pain was potentially due to coexisting lumbar pathology. Intra-operative blood was minimal and there were no post operative or radiological complications in any patient.

Conclusion: Percutaneous HMA screws are a satisfactory way to achieve sacro-iliac stabilisation.

Idiopathic anterior knee pain (AKP) is common in adolescents and young adults. Most believe that the origin of the problem lies in the patello-femoral joint. Hamstring tightness has also been attributed as an important cause.

The aim of our study was to compare biometric parameters in patients with idiopathic AKP and controls. We also wanted to assess whether there was a difference in the relative electromyographic (EMG) onset times of the medial and lateral hamstrings.

We prospectively recruited patients with idiopathic anterior knee pain in the age group 11 to 25. Patients, but not the control population, had AP, lateral and skyline radiographs taken to rule out other pathology.

We had 34 patients (60 knees) with a minimum one year follow up. There was no difference in the symptoms of patients who attended physiotherapy as compared to those who did not. Patients with knee pain had significantly more hip external rotation (63 deg) as compared to the control (47 deg) group (p=0.001). Patients also had significantly more hamstring tightness (p=0.04).

Surface EMG was recorded (17 patients and controls each) from the medial and lateral hamstrings during 3 repetitions of a maximal voluntary isometric contraction exercise with the knee at 45° of flexion. The lateral hamstrings contracted 48.7 m.sec earlier than the medial hamstrings in patients as compared to controls.

AKP is a multifactorial and self-limiting disorder. Earlier contraction of the lateral hamstrings may cause tibial external rotation and contribute to the symptoms. Our data suggests that physiotherapy did not significantly alter the course of the condition. We believe that increased hip external rotation may contribute to the symptoms by increasing medial facet stress.

Background: Radicular pain has been reported even in the absence of a compressive lesion. It has been postulated that annular tears provide a conduit for pro-inflammatory substances, which can leak around the nerve root causing radiculitis. A link between the side of back pain and the side of the annular tear has been reported.

Objective: To establish whether the side of the annular tear may influence the side of the leg in a non-compressive setting.

Methods and patients: We identified 121 patients from the patients referred to our unit with back and radicular leg pain. The mean age of the cohort was 50 yrs and 49% were male. All these patients were investigated with an MRI scan that demonstrated no compression of the nerve root. We used strict exclusion criteria to exclude the patients with any neural compression, previous lumbar operation, degenerative deformity or an associated pathology such as peripheral neuropathy.

Results: The annular pathology was described as annular tears (47 patients) and non compressive disc bulges (106 patients). The odds ratio for the concurrence of an annular tear causing ipsilateral leg pain is 1.05 and for a non-compressive disc bulge causing ipsilateral leg pain is 2.14

Conclusion: A non-compressive disc bulge is more likey to cause radicular symptoms than an annular tear. Though, both these annular lesions can cause ipsilateral nerve root symptoms.

Introduction: We report on a group of 20 metal-on-metal resurfaced hips (17 patients) presenting with a soft tissue mass associated with various symptoms; these masses we termed pseudotumours. All patients underwent plane radiography; CT, MRI and ultrasound investigations were also performed for some patients. Where samples were available histology was performed.

Methods: All patients in this series were female. Presentation was variable; the most common symptom was pain or discomfort in the hip region. Other symptoms included spontaneous dislocation, nerve palsy, a noticeable mass or a rash. The common histological features were extensive necrosis and lymphocytic infiltration. Fourteen of the 20 cases (70%) have so far required revision to a conventional hip replacement and their symptoms have either settled completely or improved substantially since the revision surgery. Two of the three bilateral cases have asymptomatic pseudotumours on the opposite side.

Conclusions: We estimate that about 1% of patients develop a pseudotumour in the first five postoperative years after a hip resurfacing. The cause of these pseudotumours is unknown and is probably multi-factorial, further work is required to define this; they may be manifestations of a metal sensitivity response. We are concerned that with time the incidence of these pseudotumours will increase.

We reviewed the results at nine to 13 years of 125 total hip replacements in 113 patients using the monoblock uncemented Morscher press-fit acetabular component. The mean age at the time of operation was 56.9 years (36 to 74). The mean clinical follow-up was 11 years (9.7 to 13.5) and the mean radiological follow-up was 9.4 years (7.7 to 13.1). Three hips were revised, one immediately for instability, one for excessive wear and one for deep infection.

No revisions were required for aseptic loosening. A total of eight hips (7.0%) had osteolytic lesions greater than 1 cm, in four around the acetabular component (3.5%). One required bone grafting behind a well-fixed implant. The mean wear rate was 0.11 mm/year (0.06 to 0.78) and was significantly higher in components with a steeper abduction angle.

Kaplan-Meier survival curves at 13 years showed survival of 96.8% (95% confidence interval 90.2 to 99.0) for revision for any cause and of 95.7% (95% confidence interval 88.6 to 98.4) for any acetabular re-operation.

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.

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.

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.

Aim: To assess the ease of use and reliability of PICC lines for the delivery of intravenous antibiotics in children with septic joints.

Method: Over a twelve month period 22 children with septic joints were prospectively recruited. All received open arthrotomy and washout prior to commencing antibiotic treatment. At the time of surgery, a PICC line was inserted. All children were given intravenous antibiotics for two weeks then oral antibiotics for four weeks. Inflammatory blood markers were reviewed regularly. Upon removal of the PICC line the tip was sent for microbiological testing.

Results: All 22 children made a full recovery with a minimum of twelve months follow up (range 12–20 months). All PICC line tips were negative for microbiological culture after 48 hours.

Conclusion: Peripheral cannulation for intravenous access in children can be challenging. Younger children have chubby limbs and often fragile veins. Even with the use of topical analgesics the procedure can be traumatic for a young child. A PICC line inserted at the time of the surgical washout of the infected joint seems an ideal solution. PICC lines are safe, reliable and allow for at least two weeks of intravenous access, avoiding the need for regular re-cannulation of children.

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.

Aim: To study the adequacy of reduction of DDH postoperatively using MRI.

Method: Ten consecutive children with DDH who underwent open reduction and femoral osteotomy using Coventry stainless steel implants were scanned postoperatively.

Results: MRI gave reliable diagnostic information in all cases. The position of the femoral head in the acetabulum was clearly seen, despite artefact due to the metal. The mean scanning time was 3 minutes 45 seconds (range: 2 minutes 20 seconds – 5 minutes 30 seconds) and the total time in the MRI suite was between 7 and 10 minutes. No child required sedation.

Conclusions: The use of MRI scanning has been described after closed and open reduction of the hip in DDH to check hip position but has not previously been reported after open reduction with femoral osteotomy and the use of metalwork. Satisfactory images, comparable time and cost to CT scanning and the lack of exposure to ionising radiation make MRI an appealing method of imaging. We recommend it as the investigation of choice in this patient group.

The Johns Hopkins University Department of Orthopaedics at the Good Samaritan Hospital, Baltimore, Maryland USA

Introduction: Historically, bone scintigraphy has been advocated as a useful diagnostic tool for patients with suspected osteonecrosis or in screening for multifocal disease. The principle aim of this study was to evaluate the sensitivity of bone scanning relative to magnetic resonance imaging in the diagnosis of osteonecrosis.

Methods: Forty-eight patients presented with suspected osteonecrosis of the shoulder, hip, knee, or ankle. All patients underwent simultaneous (less than three months apart) bone scans and magnetic resonance imaging studies as part of a diagnostic work-up. Histological confirmation of osteonecrosis was obtained for all suspected lesions in the study. The diagnostic yield for each imaging modality was then assessed and compared.

Results: All one hundred sixty-three (100%) histologically confirmed lesions were identified by magnetic resonance imaging, while only ninety-one lesions (56%) were identified by bone scan. There was complete uniformity of bone scans with magnetic resonance images in only 38% of patients (eighteen of forty-eight). Bone scanning identified 72% of lesions (forty-seven of sixty-five) in oligofocal patients (less than two involved joints) compared with 45% of the lesions (forty-four of ninety-eight) in multifocal patients (more than two joints involved). Sensitivity of the lesions was highest for the knee and hip and lower for the shoulder and ankle. Larger and later stage lesions had higher bone scan sensitivity.

Conclusions: The results of this study have demonstrated the low sensitivity of bone scintigraphy for diagnosing symptomatic osteonecrosis. Bone scanning did not detect 44% of the lesions (seventy-two of one hundred sixty-three). This study does not support the use of bone scans as a diagnostic or screening tool for this disease.

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.

Introduction: Cementless total hip arthroplasty has been advocated for osteonecrosis of the femoral head (ONFH) as these patients are generally younger and more active than patients with osteoarthritis (OA). Since introduced in the early 1980’s, there have been several generations of cementless total hip prostheses. This study examined the outcome of the femoral stem of four generations of uncemented total hip prostheses.

Materials and Methods: One hundred and fifty-eight hips in 135 osteonecrosis patients (71 men, 64 women) who had a mean age of 46 years (range, 17 to 83) were included. The total number of prostheses included: PCA™ (77), E Series™ (47), Meridian™ (18), and Citation™ (16) (all Stryker, Mahwah, New Jersey). The mean follow-up was 105.5 +/− 60.8 months (range, 20 to 257 months). As part of an ongoing IRB-approved study, data collected includes Harris Hip (HHS) and QOL scores, re-operations (including revisions), and complications.

Results: The femoral components of 142 cases were not revised. These patients had a mean HHS of 86.3 +/− 13.2 points. Of the 15 revisions (9.6%), the primary reasons were loosening and/or significant osteolysis, but there was one infection and one chronic dislocation. The revisions included 10 PCA™ (13.0%) with a mean time to revision of 85 months (range, 25 to 132); 2 E Series™ (4.3%) with a mean time to revision of 85 months (2 cases in one patient; 68 and 101 months); 2 Meridian™ (11.1%) with a mean time to revision of 193 months (2 cases; 98 and 107 months); and 1 Citation™ (6.3%) with a time to revision of 30 months. The pooled revision rate of the 2^nd, 3rd, and 4^th generation was 5 of 80 (6.3%).

Discussion: There were no significant difference in revision rates between the different generations of uncemented femoral components (Chi Square, p=.433). However, the revision rates for the later generations were lower than the earlier generations.

Purpose: Subject-specific computational models of anatomical components can now be generated from image data and used in the assessment of orthopaedic interventions. Whilst such models are becoming more commonplace, there are few studies that have investigated the effects of element size or the level of morphological detail that is required to model complex hierarchical structures such as trabecular bone [1,2]. The purpose of this study was to investigate the modelling of the mechanical properties of a trabecular-like material under compression, and in particular to evaluate the relationship between the grey-scale dependent density, determined from microCT, and the elastic modulus at different levels of mesh density.

Materials and Methods: A specific open cell rigid foam (pcf 7.5, Sawbone, Sweden), with a porosity over 95% and cell size between 1.5 and 2.5 mm, was chosen to represent human cancellous bone. Five cylindrical specimens (24 mm diameter, 19 mm height) were compressed under a maximum displacement of 0.35 mm in a materials testing machine. All the specimens were imaged by microCT (ƒÝCT80, Scanco Medical, Switzerland) before the test to provide the geometry and greyscale distribution. Corresponding finite element models of each specimen were generated using proprietary software (ScanFE, Simpleware, UK) with an element size of 1.5 mm. The elastic modulus of each element was based on the image greyscale using a conversion factor that was determined, through trial-and-error, by matching the predicted displacement with the experimental measurement in the linear region (> 0.2 mm). For each specimen, models of higher and lower mesh densities were constructed by down-sampling the microCT output to different levels. The smallest element size was limited to 0.5 mm due to computational restrictions, however a smaller 8 mm cube of the material was also analysed, with element sizes down to 0.25 mm.

Results: From the experimental tests, the mean apparent elastic modulus of the specimens was found to be 15 MPa, as compared with 18 MPa specified by the manufacturer. For the computational models, the predicted elastic modulus of the whole specimen models was found to decrease with decreasing element size. In particular, there was a large drop in the predicted values when the element size was of the same order as the cell size. With larger elements, the results indicated some convergence and there was reasonable agreement with the experimental results. For the cube model with smaller element sizes, the predicted moduli values again appeared to converge as the element size was reduced to 0.25 mm.

Conclusion: The results of this study show that the optimum conversion factor from an image greyscale value to an elastic modulus varies with element size. If the finite element method is to be used effectively to model bone, then the mesh size must either be sufficiently large to use a continuum approach or sufficiently small to capture the behaviour of the individual trabeculae. Different conversion factors will be required to determine the material properties from the image greyscale in each case.

Introduction: Morton’s neuroma is a common cause of foot pain. For this study, we assessed the efficacy of a series of sonographically guided alcohol injections into the lesion.

Method: One hundred and one consecutive patients with Morton’s neuroma were included in this prospective series. An average of 4.1 treatments per person wee administered, and follow-up images were obtained at a mean of 21.1 months after the last treatment (range, 13–34 months).

Results: Technical success was 100%. Partial or total symptom improvement was reported by 94% of the patients, with 84% becoming totally pain-free. The median visual assessed pain score decreased from 8 before treatment to 0 after treatment (p< 0.001). Transitory increased local pain occurred in 17 cases (16.8%). There were no major complications. Thirty patients underwent sonography at 6 months after the last injection and showed a 30% decrease in the size of the neuroma.

Discussion and Conclusion: We conclude that alcohol injection of Morton’s neuroma has a high success rate and is well tolerated. The success rate is acceptable at 84% whilst being associated with a low morbidity. The treatment avoids surgery and allows continued mobility with patients being able to weight bear and perform their usual activities of daily living. We advocate reserving surgical management for non-responders.

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.

Introduction: In the evaluation of various treatments that may have an effect on bone, there are certain inherent difficulties in selecting an appropriate outcome measure to determine whether a specific treatment is efficacious. This is particularly true for clinical studies.

Methods: Using Pubmed, a service of the U.S. National Library of Medicine that searches MEDLINE and other life science journals for citations of biomedical articles, a review of the current instruments used for outcome measures relating to osteonecrosis and bone blood flow was conducted. Abstracts from previous ARCO meetings were also reviewed.

Results: For the treatment of osteonecrosis, most outcome measures have focused on pain relief, surgery or need for surgery, disease progression (advancing stage), and change in lesion size. The first three options may be influenced by investigator bias and knowledge/experience. The last option may also be influenced by the technique used.

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.

Conclusion: Although there are a number of tests that can be used to evaluate the effect of a specific treatment on osteonecrosis, the definitive assessment will likely remain whether the disease progresses to the point that major surgery (resurfacing, vascularized fibular grafting, total joint replacement, e.g.) is required to relieve pain and restore function.

Introduction and aims: Familial aggregation of low back pain (LBP) symptoms has been described. However, this may be due to genetic factors or common exposure to environmental factors. This study evaluated the relative contribution of genetic and environmental factors to childhood LBP.

Methods: Data was collected from 1995 to 1998 from a national sample of 1790 Finnish twins aged 11-years. A validated pain questionnaire was used to assess LBP pain. Information was also collected on children’s perception of parent-child relationships, parenting behaviours and home environment. In addition, children were asked about various sedentary and active life-style activities. Variance components for genetic and environmental factors were estimated by using biometric structural equation modelling techniques.

Results: The prevalence of LBP at least once a month was 15.7%, and at least once a week was 6.7%. There was small difference in pairwise similarity of LBP between monozygotic and dizygotic pairs, suggesting little genetic influence. LBP was not associated with either sedentary or active lifestyle activities, but was strongly associated with children’s unsatisfactory perception of the following: home environment (p< 0.001), parenting behaviours (Spearman rho = 0.12, 95% CI 0.06–0.18), relationship with mother (p=0.02) and father (p=0.04). Of the total variance in LBP, 41% (95% CI 34 to 48) could be attributed to shared environmental factors within families; and 59% (52 to 66) to unshared environmental factors.

Conclusion: Genetic factors seem to play a very minor role in LBP in 11-year-old twins. Rather than being related to various aspects of lifestyle activities, childhood LBP is best predicted by children’s perception of home environment and family functioning.

The administration of intra-articular local anaesthetic is common following arthroscopy of the knee. However, recent evidence has suggested that bupivacaine may be harmful to articular cartilage. This study aimed to establish whether infiltration of bupivacaine around the portals is as effective as intra-articular injection.

We randomised 137 patients to receive either 20 ml 0.5% bupivacaine introduced into the joint (group 1) or 20 ml 0.5% bupivacaine infiltrated only around the portals (group 2) following arthroscopy. A visual analogue scale was administered one hour post-operatively to assess pain relief. Both patients and observers were blinded to the treatment group. A power calculation was performed.

The mean visual analogue score was 3.24 (sd 2.20) in group I and 3.04 (sd 2.31) in group 2. This difference was not statistically significant (p = 0.62).

Infiltration of bupivacaine around the portals had an equivalent effect on pain scores at one hour, and we would therefore recommend this technique to avoid the possible chondrotoxic effect of intra-articular bupivacaine.

Purpose: To alert the Orthopaedic fraternity that smoking needs to be considered in the Paediatric population and highlight it’s adverse effect on bone healing index.

Method: During assessment of Paediatric patients who had undergone limb reconstruction surgery, a sub-population was found to have a prolonged time to consolidation of the regenerate to norm. Screening for contributing factors, we were surprised to learn that this subgroup were active smokers. Revisiting their radiographs, it was felt that the quality of the regenerate appeared to differ from non-smokers.

Results: We identified 12 patients who were active smokers. 2 also had parents who smoked. They all exhibited a prolonged time to regenerate consolidation. We calculated their bone healing indices to compare with non smokers and found significant differences.

Conclusion: Smoking has adverse effects on bone healing in children as well as adults. We have drawn up an advise sheet to make patients and their parents aware of the adverse effects of active and passive smoking on bone healing.

We have studied the natural history of a first episode of dislocation after primary total hip replacement (THR) to clarify the incidence of recurrent dislocation, the need for subsequent revision and the quality of life of these patients.

Over a six-year period, 99 patients (101 hips) presented with a first dislocation of a primary THR. A total of 61 hips (60.4%) had dislocated more than once. After a minimum follow-up of one year, seven patients had died. Of the remaining 94 hips (92 patients), 47 underwent a revision for instability and one awaits operation (51% in total). Of these, seven re-dislocated and four needed further surgery. The quality of life of the patients was studied using the Oxford Hip Score and the EuroQol-5 Dimension (EQ-5D) questionnaire. A control group of patients who had not dislocated was also studied. At a mean follow-up of 4.5 years (1 to 20), the mean Oxford Hip Score was 26.7 (15 to 47) after one episode of dislocation, 27.2 (12 to 45) after recurrent dislocation, 34.5 (12 to 54) after successful revision surgery, 42 (29 to 55) after failed revision surgery and 17.4 (12 to 32) in the control group. The EuroQol-5 dimension questionnaire revealed more health problems in patients undergoing revision surgery.

Introduction: Sequential staged distraction with fixed rate and rhythm, alternative compression and distraction is well described in the literature to treat non-unions. However we looked the union in established non-unions of tibia using one stage distraction without further manipulation at the fracture site maintaining the stability.

Materials and Methods: 12 patients with established tibial non-unions were referred during the period of 2001–2005. 2 cases were infected non unions. All patients were symptomatic and exhibited deformity at the non-union site. Ten males, two females were in the study group with a mean age of 39.2 years. The location of non-union was distal 1/3 of tibia in 8 cases and 2 cases of proximal and middle 1/3. External fixation was used to acutely distract the fracture (one stage) and tension the soft tissues to attain fracture stability. Infection at the fracture site required further operative debridement. Regular followup with radiographs to assess the union.

Results: Osseous union was achieved in all the cases at an average time period of 17.2 weeks. There was no recurrence of osteomyelitis in the infected cases following secondary debridement. All the patients were pain free and fully mobile without aid at review.

Conclusion: We concluded that acute distraction osteogenesis produces fracture union in selected established cases of non union. This method can be used to obtain impressive gains in the lengths of the long bones. Bone is uniformly produced regardless of the location of the non union. This is more patient compliant, effective and relatively easy to perform.

AIM: The purpose of this prospective study was to asses the outcome of antegrade intramedullary wiring of displaced distal end of fifth metacarpal fracture in skeletally immature. Intramedullary wiring for fracture metacarpals have been well described in the literature. Retrograde wiring for neck of metacarpal fractures have been associated with limitation of extension at metacarpo-phalangeal joint due to involvement of gliding extensor mechanism. Foucher described ‘Bouguet’ osteosynthesis with multiple wires for metacarpal neck fracture which can be technically demanding in small bones of children. We describe an antegrade wiring using a single bent K-wire at the tip for reducing and stabilising displaced metacarpal neck fracture by rotating 180 degree after crossing fracture site, a method similar to Methaizeau technique for stabilisation of displaced radial neck fractures using nancy nail.

METHOD: Between 2000 to 2006 we treated 9 boys with displaced distal end of fifth metacarpal fracture +/− rotational deformity of little finger using above technique. All of them had closed injuries and the indication for surgery was rotatory mal-alignment or fracture angulation more than 40 degrees. The assessment involved a clinical and radiological examination. The mean age was 13 years. The mean follow-up was 15 months.

RESULTS: All fractures healed in anatomical alignment. There was no loss of active or passive movement of the little finger metacarpo-phalangeal joint or weakness of grip strength in any children. All children returned to pre-injury activity level within 4–6 weeks. There were no complications.

CONCLUSION: Early results of treating displaced little finger metacarpal neck fracture in children using antegrade intramedullary wire are encouraging.

Aim: Spinal stenosis is a known entity in achondroplasia and a need for screening for the symptomatic children was identified in a tertiary limb reconstruction service. The aim of this study was to evaluate whether clinical and radiological imaging would identify the at risk group.

Materials and methods: 205 achondroplastic children were treated at our service in the last 20 years. A prospective clinical screening programme for spinal stenosis which also included the MRI imaging of entire spine was however introduced only in 1996. 26 patients were available for this study. Case notes were reviewed for clinical symptoms and neurological signs. MR images were assessed for stenosis especially at Cervico medullary junction and lumbar level. Canal diameters were measured at all spinal levels from CMJ to lumbo-sacral junction. Neurosurgical interventions were recorded. An attempt was made to identify high risk factors that required surgical intervention.

Results: Delayed milestones were observed in 7 patients. Positive history of back pain or radicular pain was obtained in 10 whereas 10 patients had symptoms of neurogenic claudication. Brisk reflexes and clonus were consistent findings. Severe foramen magnum narrowing was observed in 23 patients and 13 showed ‘kinking’ or ‘pinching’, suggesting severe compression. Of the 17 patients seen by neurosurgeons 6 required single or multiple surgical decompressions. Ventriculo-peritoneal shunt was inserted in 4. 5 children required CMJ decompression and one required lumbar canal decompression. There was a 7 mm difference in AP diameter measured on MRI at CMJ between the two non operated and operated groups. Female patients with delayed milestones and CMJ narrowing to less than 25 mm were identified as high risk.

Conclusion: The cause of increased morbidity and mortality in young achondroplasts is attributable to severe CM compression. Sudden death can occur by acute or gradual progressive encroachment of respiratory centre at medulla oblongata. We were able to identify symptomatic patients early before developing myelomalacia and cord changes by screening all symptomatic children with achondroplasia. We propose that female gender, especially with delayed milestones as another high risk factor. We stress upon the importance of developing a nationalised selective screening programme with guidelines in specialist orthopaedic and joint multi-disciplinary Skeletal Dysplasia clinics.

Introduction: Ankle fractures accounts for 25% to 38% of all physeal fractures. An accurate diagnosis is the key to the appropriate management of these fractures. Traditionally the management decisions have been based on x-ray findings. We have used computed tomograpy (CT) scans in additon to x-rays in the management of these fractures.

Objective: To determine the usefulness of computed tomograpy (CT) scans in the management of ankle fractures in children.

Materials and Methods: Between 2001 to 2005, 53 patients with ankle fractures who were managed in our unit had CT scans in addition to plain radiographs. The mean age was 12.3 years (+/− 2.1). The radiographs were reviewed by senior paediatric orthopaedic surgeon who classified the fractures and formulated treatment plans (operative/non-operative). The CT scans were then reviewed by the respective surgeon and a similar exercise undertaken. A Radiologist confirmed that the fractures were classified accurately.

Results: In 47% (25 fractures) the x-ray diagnosis/classification tallied with the CT scans whilst in 53% (28 fractures) the CT scans showed the fractures were more extensive/serious than noticed on the x-rays. The management was changed in 34% after reviewing the CT scans, In 9 from operative to non-operative treatment and in the other 9 from non-operative to operative treatment.

Conclusion: We have found CT scans to be more useful than plain radiographs in making an accurate diagnosis of ankle fractures in children and thus planning appropriate management.

Aim: To investigate and compare the effects of two types of LCS total knee arthroplasty on joint proprioception and range of motion.

Methods: 47 patients were randomised to receive either a LCS AP glide or Rotating platform prosthesis. Clinical scores (Oxford knee score, American knee society score, EuroQol), range of motion and proprioception were assessed prior to and at 3,6, and 12 months after the operation. Proprioception was assessed in terms of absolute error angle (mean difference between the target angle and the response angle). Knee angles were measured in degrees using an electromagnetic tracking device, Polhemus 3Space Fastrak that detected positions of sensors placed on the test limb. Student’s t-test was used to compare the mean of two groups (with a level of significance of p < 0.05).

Results: Both groups were comparable in terms of pre-operative range of motion, oxford knee score, American knee society score, EuroQol score and proprioception. There was statistically significant improvement in the Oxford knee score, AKSS and EuroQol score in both groups (p< 0.001), but there was no difference between the groups with respect to these parameters. There was improvement in the proprioception (reduction in absolute error angle) in both groups though this was not significant statistically (p> 0.05).

Conclusions: We did not find significant difference between AP glide and RP LCS knee arthroplasty in terms of improvement in proprioception and range of motion.

Introduction: Interest in hip resurfacing has recently been renewed by the introduction of metal-on-metal designs; it is being increasingly used for young patients, with over 30,000 implanted worldwide. The 5 year clinical results appear promising, but there are no long term data available. Radiostereometry (RSA) measures of implant migration have been able to predict implant failure; specifically large and continuous migration predicts aseptic loosening. We present the results of a five year RSA study examining the migration of the Birmingham Hip Resurfacing (BHR).

Methods: Twenty-four subjects with primary OA were implanted with the BHR device and with bone markers for RSA. RSA measurements were taken at 3, 6, 12, 24 and 60 months. The migration of the head and the tip of femoral component were measured in 3D.

Results: Preliminary analysis showed that the total 3D migration of the head and tip over five years was 0.32mm and 0.23mm respectively.

Discussion: A distal migration of more than 0.4mm over 2 years increases the likelihood of failure in conventional stems. The total migration of the BHR was approximately 0.3mm over a five year period, significantly less than cemented THR devices. The device is stable and this is promising for long-term survival.