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Current treatment modalities for chronic non-healing leg ulcers are time consuming, expensive, and only moderately successful. The use of sub-atmospheric pressure dressings, available commercially as the vacuum-assisted closure (VAC) device, has been shown to be an effective way to accelerate healing of various wounds. There is patented computer-controlled system technology available that is established V.A.C.(KCI Concepts, San Antonio, Texas) treatment. Reducing costs associated with wound treatments is therefore becoming an increasingly important issue in health care. This study included 45 patients with open wounds of the lower extremity with exposed tendon, bone, hardware or with osteomyelitis. Fifteen wounds were the result of trauma. Thirty wounds were non-traumatic (twenty dehisced or infected orthopedic surgical wounds, five pressure sores and five miscellaneous wounds). We use the vacuum therapy as a tool to bridge the period between debridement and definite surgical closure in full-thickness wounds. Treatment efficacy was assessed by semi-quantitative scoring of the wound conditions (signs of rubor, calor, exudate and fibrinous slough) and by wound surface area measurements. In our technique, the system consist of a sterilized simple foam sponge, a vacuum drain, two blood infusion kit and a negative pressure aquarium air pump, one liter salin bottle, an steril drape. It’s mean applying time ten minutes and mean cost at the first time 36 dollars consecutive seances 11 dollars (the aquarium air pump 15 dollars – an electrical engineer change it positive to negative air pressure mode). Forty-five patients who needed open wound management before surgical closure were included in this study. Healing was characterized by development of a clean granulating wound bed (“ready for surgical therapy”) and reduction of wound surface area. To quantify bacterial load, cultures were collected. The total quantitative bacterial load was generally stable. However, nonfermentative gram negative bacilli showed a significant decrease in vacuum-assisted closure-treated wounds, whereas Staphylococcus aureus showed a significant increase in vacuum-assisted closure-treated wounds. Succesfull wound closure was obtained 43 of 45 patients. 41 wounds were closed with split-thicknees skin graft. The median time to complete healing was 31 days (27.5 to 34.5) and wound bed preparation was 7 days (5.8 to 8.2) in the non-computerized V.A.C. therapy, similar with the computerized therapy 29 (25.5 to 32.5–7 days 5.7 to 8.3) This study shows a positive effect of vacuum-assisted closure therapy on wound healing, expressed as a significant reduction of wound surface. The costs of computerized wound care were higher than our techique of V.A.C. and similar clinical results at the end.
In modern orthopaedics surgery, the pneumatic tourniquet has become an essential tool that paved the way to many of the advances in trauma and orthopaedic surgery. Tourniquet slippage is one of the challenging disadvantages of it use. This study examines the possibility of reducing tourniquet slippage by comparing two different tourniquet application techniques.
Twenty two patients were included in the study. Thirteen were males and eight were females. The average age was fifty five years. The patients were randomized into two groups, a controlled, and a modified tourniquet application technique groups. There were eleven patients in the control group and ten in the modified group. A standard tourniquet application technique was used as a control by applying Softband (Orthoband) alone to skin prior to application of tourniquet; this was compared to a modified version where a drape (Steridrape) was used as an interval layer.
There was a strong statistical significant difference in tourniquet slippage between the two groups, p< 0.0001 the control group being the better performer.
We concluded that steridrape interval makes tourniquet slippage more likely to occur.
Dabigatran etexilate (Pradaxa®) is an oral direct thrombin inhibitor that was recently approved in Europe and Canada for the prevention of venous thromboembolism (VTE) in patients undergoing elective total knee replacement or total hip replacement surgery. Two pivotal clinical trials, RE-MODEL (
In response to the recent publication in April 2007 of NICE guidelines on venous thromboembolism, we report our practice and experience of VTE in adult hip and knee arthroplasty. It is generally agreed that the 2 major complications of VTE are sudden death as a result of pulmonary embolism and post thrombotic syndrome. NICE guidelines make 2 assumptions:
That chemical and mechanical prophylaxis can reduce these complications That Orthopaedic surgery, in particular elective Primary Joint Replacements are particularly high risk procedures with respect to these 2 complications.
We have studied a large cohort of patients who had Aspirin only as chemical prophylaxis to determine the incidence of clinical thromboembolism before and after discharge and the mortality from PE at 90 days. We performed a retrospective analysis of consecutive patients undergoing primary total knee and hip replacement from November 2002 to November 2007. In total 2050 patients had total knee replacement and 2203 patients had total hip replacement. All patients were treated at one specialist centre under the care of one surgeon. Data was complete and accurate for all patients at 90 days post-operatively. Standard practice was the use of 150mg Aspirin from Day 1 post-operatively for a total of six weeks combined with spinal anaesthesia and early mobilisation. The overall rate for Fatal Pulmonary embolism 0.07% (3/4253), overall death rate 0.31%(13/4253), for treated non-fatal PE 0.66% (28/4253) and for treated above knee DVT was 0.33%(14/4253). Our data suggests that fatal pulmonary embolism is not common and does not account for most deaths following total hip and knee arthroplasty. We suggest there is no evidence that chemical/mechanical prophylaxis reduces the risk of sudden death from PE following elective primary joint replacement and with modern surgical practice elective hip and knee replacement should no longer be considered high risk procedures.
Dabigatran etexilate (Pradaxa®) is an oral anticoagulant licensed in multiple countries, Europe and Canada, for the prevention of venous thromboembolic events (VTE) in patients undergoing total hip replacement surgery (THR) or total knee replacement surgery (TKR). The label recommendation for therapy initiation of dabigatran etexilate is a half dose given 1–4 hours after surgery. If this is not possible, then dabigatran etexilate should be started the day following surgery with the full dose. In the European pivotal Phase III clinical trials, this initial dosing was delayed until the day after surgery in 14% of the cases. This prompted a post hoc study to analyze if these patients received adequate thromboprophylaxis. Pooled efficacy data of major VTE events (composite of proximal DVT, symptomatic DVT, pulmonary embolism and VTE-related death) from the two European pivotal trials (RE-MODEL;
This group of patients were compared with previous data collected over a 6 month period (Jan to Mar 2007 and Oct to Dec 2005) from the same hospitals for infection rates in Lower Limb Arthroplasty using 3 doses of Cefuroxime 750mg as antibiotic prophylaxis.
Surgical site infection was detected in 9 THRs (2.2%) and 2 TKRs (0.44%) in the study group as compared to infection in 13 THRs (3.1%) and 12 TKRs (2.9%) in the control group.
Using the Fisher Exact test the infection rates in THRs were not significantly different between the 2 groups (p value – 0.52) but the infection rates were significantly reduced in the study group for TKRs (p value – 0.005).
There were no complications with the use of Gentamicin as antibiotic prophylaxis.
Cefuroxime is known to promote Clostridium difficile infection and was removed from the hospital pharmacy to help meet a UK government targets to reduce the incidence. The rate of Clostridium difficile infection was reduced within the hospital with the use of single dose antibiotic prophylaxis although other measures to reduce its incidence were also introduced.
This is recommended for routine use in all elective joint replacements as it is safe, effective and easy to administer.
Dabigatran etexilate (Pradaxa®) is an oral direct thrombin inhibitor that was recently approved in Europe and Canada for the prevention of venous thromboembolism (VTE) in patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA) surgery. In the phase III studies, concomitant administration of selective nonsteroidal anti-inflammatory drugs (NSAIDs with t½≤12 hours) and acetylsalicylic acid (ASA; < 160 mg/day) was allowed during treatment with dabigatran etexilate or enoxaparin. Due to the potential additional anticoagulant activity of these concomitant therapies a separate post hoc analysis was conducted to investigate the bleeding risk in these patients. We analysed the pooled study population (8,135 patients) from the three phase III trials in THA and TKA surgery (RE-MOBILIZE, RE-MODEL and RE-NOVATE) for major bleeding events (MBE). All MBE, which included surgical site bleeds, were assessed by an independent, expert adjudication committee. We report the rates of MBE and odds ratios (with 95% confidence intervals [CI]) for comparison of the subgroup concomitantly treated with NSAID (or ASA) versus the subgroup of patients without concomitant antithrombotically active medication. The overall rate of MBE (with and without NSAIDs and ASA) was 1.4% [CI 1.0–1.9], 1.1% [0.7–1.5] and 1.4% [1.0–2.0] with dabigatran etexilate 220 mg, 150 mg, and enoxaparin, respectively. Of the total population, 57.4% of patients received concomitant antithrombotic treatment: 54.1% received NSAID and 4.7% received ASA. The MBE rate in patients receiving dabigatran etexilate or enoxaparin plus NSAIDs was similar to the rate in patients taking only dabigatran etexilate or enoxaparin; 1.5% vs. 1.4% [OR 1.05; 0.55–2.01] for dabigatran etexilate 220 mg, 1.1% vs. 1.0% [OR 1.19; 0.55–2.55] for dabigatran etexilate 150 mg, and 1.6% vs. 1.2% [OR 1.32; 0.67–2.57] for enoxaparin. A similar pattern was seen in patients concomitantly receiving ASA; in this small group only a few patients with MBE were observed: 2 (1.6%) in the dabigatran etexilate 220 mg group, 2 (1.6%) in the 150 mg group, and 4 (3.0%) in the enoxaparin group. No relevant differences in risk for MBE were detected between treatments by co-medication subgroup or within treatment groups when comparing patients receiving dabigatran etexilate or enoxaparin only versus those concomitantly receiving NSAIDs or ASA. In conclusion, patients concomitantly receiving dabigatran etexilate and NSAIDs (with t½ ≤12 hours) or ASA (< 160 mg/day) have a similar risk of MBE to patients taking only dabigatran etexilate. These data support the use of dabigatran etexilate for the prevention of VTE in patients after THA or TKA, when concomitant use of NSAIDs or ASA (< 160 mg/day) is required.
Every surgeon needs to audit the quality of his work to ensure that complication rates are low, good function persists for the intermediate term, and patient satisfaction remains high. The use of the 12-point shortened WOMAC score and Orthowave patient satisfaction survey provides enough information for quantitative assessment of most practices. When applied to my hip arthroplasty practice, analysis of data related to 426 consecutive patients at 1–9 years of follow-up (mean 3.5) revealed pain relief was good to excellent in 96%; rate of recommendation of surgery was 97%. Overall satisfaction was good to excellent in 95%. Mean WOMAC scores improved from a preoperative mean value of 32.5 to mean 6.6 at latest follow-up. When the same scoring system was applied to my knee arthroplasty practice, results were surprisingly inferior. Potential areas for technical improvement were then identified and implemented. This study highlights the simplicity and usefulness of the shortened WOMAC score and Orthowave patient satisfaction survey in assessing and improving an arthroplasty practice.
The oral direct thrombin inhibitor dabigatran etexilate (Pradaxa®) was recently approved in Europe for the prevention of venous thromboembolism (VTE) in patients undergoing elective total knee or total hip replacement surgery. In the Phase III RE-MODEL (
Overall in-hospital fracture mortality was 1.3% (117 fractures). Fracture specific in-hospital mortality was 2.8% (75 fractures) for hip fractures, 5% (13) for non rami pelvic fractures, 1% (20) for spinal fractures, 0.5% (6) for femoral fractures and near 0%(1) for tibial fractures. In-hospital mortality increased with age (0.4% mortality between 21–40 years, 0.6% between 41–60 years, 0.9% between 61–70 years, 1.7% between 71–80 and 4% between 81–90 years). Infection related causes of death were most common. The mean duration from hospital admission until death was 19 days (SD 20, range 1–34). More hip and spine fractures were seen in Chinese and more femoral and tibial fractures were seen in Malay and Indian patients, and this difference was statistically significant. Logistic regression analysis showed only increased patient age, male gender and fracture type as statistically significant risk factors for increased in-hospital mortality. Subgroup analysis showed a 30 and 20 times increased risk of in-hospital mortality for pelvic (p=0.001, 95% CI 4, 241) and hip (p=0.003, 95% CI 3, 159) fractures respectively.
The average revision rate in peer reviewed literature is significantly lower than in arthroplasty register data-sets.
Studies published by the inventor of an implant tend to show superior outcome compared to independent publications and Arthroplasty Register data. Factors of 4 to more than 10 have been found, which has a significant impact for the results of Metaanalyses.
When an implant is taken from the market or replaced by a successor there is a significant decrease in publications, which limits the detection of failure mechanisms such as PE wear or insufficient locking mechanisms.
The final statement made about the product under investigation seem to follow a certain mainstream.
We have come up with a 4-part stratification based on the patient’s primary condition and comorbidities and have evaluated this for a single-surgeon cohort of TKR patients and a multi-surgeon group of THR patients. We present the results and the implications of the findings and highlight the usability of the system.
After fixation of the device on the lower extremity and positioning of the patient in the starting position the device was first externally and then internally rotated at an applied torque of 5,10 and 15 Nm. To decrease the measurement error the procedure was repeated 5 times. Afterwards 5 measurements were performed by a second examiner in the same way to measure the inter-observer reliability. All 30 patients were measured again after a mean of 31 ± 43 days by the same examiners to test the intra-observer reliability. Statistical analysis was performed using the intra class correlation coefficient (ICC). Pearson correlation coefficient were used to compare the measurements of the left and the right knee.
The comparison of the measurements of the left and the right knee showed high Pearson correlation (.90) at all applied torques.
Current costs and methods of local waste disposal were also investigated.
Revenue generated from recycling paper is between £50–80 per tone and plastic waste between £150–180 per tonne.
The introduction of a local or national recycling policy would make a definite impact on the environment, as well as potentially saving money.
What is the effect on the length of a procedure when a trainee is involved? What is the effect on the length of a list and the number of procedures performed on the list when a trainee is involved? What percentage of cases had trainee involvement for anaesthetics and surgery? Is this is statistically significant?
Among these cases, 71% were performed by senior trainees. The consultant’s log book data also suggested the similar trends. In all comparisions, time taken by trainees to perform surgeries were statistically significant. Trainee performed with consultant scrubbed versus consultant performed (P = < 0.0001), trainee performed with consultant in theatre versus consultant performed(P = 0.0318) and trainee performed with consultant scrubbed versus trainee performed with consultant in theatre (P = 0.002)
When ranked for SJR instead of IF, five journals maintained rank, six improved their rank and six experienced a decline in rank. Biggest differences were seen for BMC MD (+7 places) and CORR (− 4 places). Group-analyses for the IF (general: 7.50 – 95%CI 3.19 to 11.81) (specialized: 10.33 – 95%CI 6.61 to 14.06) (p = 0.26), SJR (general: 6.63 – 95%CI 2.66 to 10.60) (specialized: 11.11 – 95%CI 7.62 to 14.60) (p = 0.07) and the difference between both rankings (general: 0.88 – 95%CI –1.75 to 3.50) (specialized: − 0.78 – 95%CI –2.20 to 0.65) (p = 0.20), showed an enhanced underestimation of sub-specialist journals.
The 2007 National Institute for health and Clinical Excellence (NICE) thromboprophylaxis guidelines concerning hip arthroplasty remain contentious. A survey among British Hip Society members was performed to investigate the impact of these guidelines. Information on thromboprophylactic measures before and after guideline publication was gathered in the three categories of Total Hip Replacement (THR), hip fracture and high-risk patients as defined by NICE. The response rate was 185/250 (74%). All responders used thromboprophylaxis, but only 44%, 22% and 7% indicated they were currently acting in accordance with guidance for THR, high risk and hip fracture groups respectively. 19%, 14% and 14% had changed their practice since publication of the guidance in THR, high risk and hip fracture groups respectively. The effects of the NICE guidance in influencing the responders’ thromboprophylactic protocols have been very limited. These results do not appear to endorse the authority of NICE in decisions made in this area.
EOS, a new 2D/3D digital imaging system based on Nobel-prize winning ultra low-dose X-ray radiation detection and a unique 3D toolbox with 3D reconstruction module offers a truly groundbreaking option in this field. We present results obtained during the first year of clinical use of our EOS 2D/3D system.
EOS 3D reconstruction module provided a surface reconstructed 3D model of the examined limbs and automatically displayed every clinically relevant parameters measured in the 3D toolbox. This proved to be an important feature for pre-operative planning and postoperative evaluations.
A number of studies have looked at the incidence of cervical rib in various ethnic groups, but have a number of limitations. This is the first large scale study looking at the incidence in White British with direct comparison to the Asian population. A total of 1545 consecutive cervical spine radiographs performed for any reason were collected and reviewed. 5.9% of White British and 24.9% of Asian patients had evidence of cervical rib. This was statistically significant (p< 0.0001, χ2 test). Asians are 5 times more likely compared to White British to have cervical rib (OR=5.303, 95% CI=3.825–7.354). An analysis of male Vs female difference as well as incidence of the various subtypes of cervical rib will be presented. We reccomend that the results of this study should
be considered in the assessment of patients with symptoms of thoracic outlet syndrome, taken into account during review of cervical spine radiographs and included in anatomy textbooks in the future.
Evaluate the ability of NMES prehabilitation to improve strength and functional recovery post-TKA.
A number of measurements of patellar height are in clinical use all of which reference from the tibia. The patellotrochlear index has been proposed recently as a more accurate reflection of the functional height of the patella and described in normal knees.
We compared patellar height measurements in patients with patellofemoral dysplasia.
In a retrospective analysis of the MRI scans of 33 knees in 29 patients with patellofemoral dysplasia we assessed the inter- and intraobserver reliability of four patellar height measurements: the recently described Patellotrochlear Index (PTI), Insall-Salvati (IS), Blackburne-Peel (BP) and Caton-Deschamps (CD) ratios. We also assessed the correlation between the different measurements in predicting patella alta. Three blinded observers on two separate occasions performed the measurements.
There were 21 females and 8 males with a mean age of 21.4 years (13–33).
Statistical analysis revealed good inter-observer reliability for all measurements (0.78 for PTI, 0.78 for IS, 0.73 for BP and 0.77 for CD). Intra-observer reliability was also good (0.80, 0.83, 0.75, 0.78 respectively). There was weak correlation between the PTI and the other ratios for patella alta. There was a strong correlation between the CD and BP ratios (0.96) and a moderate correlation between IS and CD and IS and BP ratios (0.594 and 0.539 respectively).
We propose the PTI as a more clinically relevant measure.
Changes in incidence rates were analyzed using Poisson regression with decade as covariate. Two sided p-values < 0.05 were considered significant. Analyses were performed in State version10.0.
The t-test was utilised for statistical analysis.
The TTDPM at 15° and JPS findings of the injured leg, before and 6, 12 months after reconstructive surgery, were statistically different (p< 0.05) for both groups.
There was no statistically significant difference for both JPS and TTDPM at 15° in flexion and extension between the findings in reconstructed and uninjured knees, at 6 and 12 months post-operatively in both groups.
No difference was found when comparing proprioceptive improvement following ACL reconstruction between the two different autograft groups.
Pain: the prevalence of poor outcomes were 6% of patients with a THR, 4% with a hip resurfacing, 12% with a TKR, 9% with a UKR and 31% with a patellar resurfacing. Function: the prevalence of poor outcomes were 12% of patients with a THR, 4% with a hip resurfacing, 16% with a TKR, 9% with a UKR and 35% with a patellar resurfacing. Hip-related quality of life: the prevalence of poor outcomes were 26% of patients with a THR, 12% with a hip resurfacing, 33% with a TKR, 32% with a UKR and 67% with a patellar resurfacing. Satisfaction: the prevalence of poor outcomes were 13% of patients with a THR, 8% with a hip resurfacing, 17% with a TKR, 11% with a UKR and 45% with a patellar resurfacing.
North Bristol Trust Small Grants Scheme provided funding for the consumables for this study.
We performed a clinical, instrumental and radiographic study on a highly homogeneous series of 100 consecutive patients with unilateral ACL lesion at 7 years of minimum follow up, alternatively assigned to a single bundle reconstruction using patellar tendon (PT) or to a double bundle reconstruction using hamstrings (DB). Mean Tegner score was 4,8 for PT and 6,5 for DB (p=0,0005). Time for sport resumption was 6,6 months for PT and 3,8 months for DB (p=0,0052). There were no significative differences between the two groups regarding range of motion and functional subjective self-evaluation. Mean anterior displacement at instrumental evaluation performed with KT2000 showed no significative differences between the two groups. Objective clinical evaluation with IKDC was superior for DB group (A=86,5%; B=13,5%) respect to PT group (A=18,7%; B=75%; C=6,3%) (p< 0,0001). We found no differences regarding anterior knee pain between and Ahlback radiographic score the two groups and we have observed no recurrence of instability after surgical treatment. Double bundle ACL reconstruction with hamstrings has showed higher results respect to single bundle ACL reconstruction with patellar tendon in terms of Tegner score, IKDC, time for sport resumption.
The conservative treatment of ACL lesions in the adolescent is unfavourable in the long term risking precocious joint deterioration. Nevertheless, literature does not agree on the timing and on the best type of surgery in this age group. The results of ACL repairs with the open technique are evaluated negatively. We present a retrospective evaluation of a case history of adolescents surgically treated with ACL reconstruction with patellar tendon or with arthroscopic reinsertion of the ACL in the case of proximal lesions and of good quality ligamentous tissue.
Coblation is supposed to enhance healing due to increasing vascularity in the degenerated tendon. In the present study the effect of coblation treatment on tendon degeneration was investigated.
A total of 32 New Zealand rabbit were enrolled in the current study. Experimental degeneration was performed by injecting prostaglandin E1 (PGE1) to bilateral achilles tendons of rabbits. Four rabbits were excluded by different reasons. Coblation and control groups were composed of 12 rabbits in each. Coblation device only touched to tendon in the control group whereas in the coblation group coblation treatment was performed through 2 cm segment to form grids with 0.5 mm apart with level four energy lasted for 500 ms. 6 rabbits in control and coblation groups were sacrificed in 6th and 12th weeks. Achilles tendons were evaluated histopathologically by modified Movin scale and immunohistopathologic examination was performed using vascular endothelial growth factor (VEGF) and type 4 collagen.
After injection of PGE1, findings similiar to chronic tendinosis were revealed. Coblation group revealed significant increment in vascularity with histopathological and immunohistochemical examination. However difference regarding healing of tendon degeneration was not significant between control and coblation group.
Coblation treatment increases vascularity in degenerated tendon, but doesn’t increase healing process.
As a tool, water jet (WJ) provides a cold cutting process. The cut is performed using water under high pressure (potential energy) by transforming it into water with high velocity (kinetic energy) using a nozzle.
This study evaluates the feasibility of performing selective cutting on the cortical bone and articular cartilage tissue by the use of plain water jetting.
Multi- and one-way analyses of variance were computed with cutting depth as dependent variable.
In the second part of the study osteochondral cylinders were obtained from the femoral condyles using:
8 mm diameter Arthrex OATS punch, 8 mm diameter diamond coated drill punch and the water jet cutting device.
Plugs were then assessed for cell viability along the cut periphery by performing live-dead cell staining and viewing under the confocal laser scanning microscope.
The margin of superficial zone cell death at the curved edge was significantly greater in the OATS punch group (390±18μm) and in the diamond drill group (440±18μm), when compared to the WJ group (10±4 μm).
Average time between re-scopes was 16 months (range 0 to 3.5 years). The numbers of patients requiring repeat knee arthroscopy for similar clinical problems were 16 out of 695 patients (2.3%). During repeat arthroscopies, 10/16 (62%) required procedures on meniscus, 4/16 (25%) for osteochondral lesions 2 patients had same diagnosis as ACL tears. 90% of partial meniscectomies were repeated on the posterior horn of both medial and lateral meniscus, and 20% required trimming of body of the meniscus.
at the level of the joint line at the mid-portion of the bone bridge and at the base of the bone bridge.
In addition, the bone density of the bone bridge was measured in Hounsfield units (HU) in the same locations. Bone density of the anterior tibial cortex lateral femoral condyle, and adjacent cancellous area, and were measured for comparisons.
In qRT-PCR a redifferentiation of human chondrocytes was shown by the transfer into diffusion-culture. Within passage 1 to 3 human chondrocytes which were cultured in monolayer lost the ability to express Collagen Type II but could regain it if they were transferred to diffusion-culture. At diffusion-culture chondrocytes showed the highest expression of Collagen type II at passage 1 when compared to monolayer or to pellet-culture.
Patello-femoral instability (PFI) affects 40 individuals per 100,000 population and causes significant morbidity. The causes of patello-femoral instability are multi-factorial, and an isolated anatomical abnormality does not necessarily indicate instability. Patello-femoral subluxation ranges from 0% (stable patella tracking) to 100% (dislocation) and there is an established relationship between the amount of subluxation and anterior knee pain. Traditionally, magnetic resonance (MR) imaging and standard radiographs are used to guide the clinician towards a suitable corrective procedure for PFI. The multi-factorial nature of patello-femoral instability is not addressed with current imaging techniques. This study aims to address which anatomical variables assessed on MR images are most relevant to patello-femoral subluxation. This information will aid surgical decision making, particularly in selecting the most appropriate reconstructive surgery.
A retrospective analysis of MR studies of 60 patients with suspected patello-femoral instability was performed. All patients were graded for degree of subluxation using a dynamic MR scan.
The patient scans were assessed for the presence of a specific range of anatomical variables:
patella alta, (modified Insall-Salvatti) patella type (Wiberg classification) trochlea sulcus angles for bone and cartilage surfaces the distance of the vastus medialis obliquis (VMO) muscle from the patella trochlea and patella cartilage thickness the horizontal distance between the tibial tubercle and the midpoint of the femoral trochlea (TTD) patella engagement – the percentage of the patella height that is captured in the trochlea groove in full extension.
The Wilk’s Lambda test for multi-variate analysis was used to establish whether any relationship was present between the degree of patello-femoral instability and bony or soft tissue anatomical variables. Non-parametric statistical tests were applied across the groups and within the groups to assess their relative significance.
The following variables showed a significant relationship with patellofemoral subluxation; distance of the VMO from the patella (< 0.001), TTD (< 0.001), patella engagement (0.001), sulcus angles (0.004) and patella alta (0.005).
This study agrees with previous work showing a significant correlation between subluxation and trochlea sulcus angle and TTD.
This is the first study to establish a significant correlation between patella engagement and radiological instability. The lower the percentage engagement of the patella in the trochlea, the greater the degree of patello-femoral instability. Patella engagement showed a more significant relationship with subluxation than patella alta.
We report a new method of predicting patello-femoral instability by measuring the overlap of the patella in the trochlea groove.
We present 10–15 year follow-up of 33 patients who underwent Elmslie-Trillat osteotomy for severe patellar subluxation or dislocation. In the literature it has been reported that tibial tubercle osteotomy predisposes to subsequent patella-femoral arthritis, however it has never been documented if pre existent knee chondral damage has any role in this development. In our group all patients had pre-op knee arthroscopy performed and extant of chondral damage was documented. We pre-formed an evaluation by long-term follow-up to determined weather pre-op chondral damage was the cause of subsequent osteoarthritis of patella-femoral joint.
All patients were invited to attend outpatient clinic for clinical examination and knee radiographs and assessed by an independent research surgeon. Mean age at follow-up was 43 years and average follow-up was 10.5 years (range 10–15 years). 90% follow-up was achieved. Knee function was assessed by clinical scores (Lysholm knee score, American Knee Score, Oxford Knee score, Tegner and Insall knee scores) and three radiographs (AP, Lateral and Merchant views) were performed.
Four patients had developed significant arthritis and underwent joint arthroplasty. Majority of patients reported good results with no further dislocation. However we noticed that extant of pre-op chondral damage was a significant factor in subsequent development of patella-femoral arthritis. We will present our data which is unique as no previous such long-term results have been reported for tibial tubercle transfers followed-up for more than 10 years and have pre-op arthroscopic documented chondral damage.
Radiographs are frequently ordered following acute knee injury. However, it is suggested that only 6 % of patients with a knee trauma have a fracture. Decision rules such as the Ottawa rules and the Pittsburgh rules have been developed to reduce the unnecessary use of radiographs following knee injury.
We prospectively reviewed all acute knee injury patients who were referred to our clinic from the emergency department over a 3 month period. The reason for ordering radiographs was analysed. The Ottawa and the Pittsburgh rules were applied to individual patients to evaluate the need for radiographs. In patients with a diagnosis of fracture, the accuracy of the Ottawa and the Pittsburgh rules was studied.
A total, of 106 patients were referred to the acute knee clinic from the emergency department. 95.28 % (101) of these patients had radiographs of their knee in the emergency department. Five (4.72%) patients had a fracture of their knee and all these cases, the Ottawa and the Pittsburgh knee rules for ordering radiographs was fulfilled. In a vast majority of cases without any fracture, the clinical reason for ordering radiographs was not clear. Using the Ottawa rules for knee radiography 25.47% (27) radiographs could be avoided without missing a fracture. Using the Pittsburgh rules, 30.19 % (32) knee radiographs could be avoided without missing a fracture.
The Ottawa and the Pittsburgh rules have a high sensitivity for the detection of knee fractures. Use of these rules can aid efficient clinical evaluation of the knee in an emergency situation without adverse clinical outcome. They may also have an implication on reducing the work load of radiology department and reduction of health costs.
Prospectively, we determined amount of meniscus loss and anatomic location of Collagen Meniscus Implant (CMI) placement after partial medial meniscectomy (PMM). At 1-year relook we determined total meniscus tissue present based on surface area coverage. We correlated percent of meniscus and anatomic location of the original lesion with function and activity levels 6 years after CMI placement. We hypothesized that meniscus amount and anatomic location would influence clinical function and activity levels.
In a prospective randomized controlled multicenter clinical trial (Level of Evidence I), 114 chronic patients (1 to 3 prior PMM on the involved meniscus) 18 to 60 years old underwent partial medial meniscectomy, and then randomly one group received a CMI to fill the meniscus defect. There were 68 PMM only controls and 46 CMI patients. At index surgery, amount and anatomic location of meniscus removed and CMI placement were documented on a standard grid. Locations were categorized as posterior (A), middle (B), or anterior (C) third. A 1-year relook was done on CMI patients, and meniscus surface area coverage was measured. Patients were followed clinically for a minimum of two years and subjectively annually thereafter. Average follow-up was 69 months (range, 24 to 92). All patients completed validated questionnaires including Lysholm and Tegner scores to assess function and activity.
For CMI patients, 29 had lesions which included posterior and middle thirds (AB), and 17 had lesions involving all three zones (ABC). Lysholm scores were significantly higher in patients with AB lesions (81) compared to ABC lesions (71), p=0.046. AB lesion patients also had significantly higher Tegner index (0.70) than ABC lesion patients (0.22), thus AB patients regained more of their lost activity, p=0.049. Comparing all patients with > 60% meniscus surface area coverage, CMI patients had significantly higher Tegner index compared to controls (0.59 vs. 0.30), p=0.036. No differences between treatment groups were seen in patients with < 60% meniscus surface area coverage. When comparing 24 month to final follow-up values, controls had no change for Lysholm (p=0.13) or Tegner (p=0.39) scores, but CMI patients improved significantly over time for both Lysholm (p=0.02) and Tegner (p=0.04) scores.
Zones of meniscus involvement influenced clinical outcomes at 6 years in CMI patients. Those whose lesions extended into all three zones did worse than those with lesions in posterior and middle zones only. Patients with successful CMI procedures yielding > 60% meniscus surface area coverage were significantly better than PMM only controls for both clinical function and activity levels. Noteworthy, CMI patients continue to improve over time for clinical function and activity levels, but PMM controls do not.
Compared to conventional road-cycling, little is known about overuse injuries in mountainbiking. The adjustment of the mountainbike seems to be crucial avoiding these syndromes. No other study has prospectively put overuse injuries into correlation with the mountainbike’s adjustment in a competition setting until now.
The 25 patients included 7 women and 18 men with an average age of 29.2 years at the time of surgery.
Preoperative evaluation was conducted using manual Lachman test, pivot-shift tests, KT-1000, magnetic resonance imaging and passive stress radiographs of both knees. In all cases preoperative clinical evaluation was graded C as per the IKDC scoring system. The preoperative side-to-side anterior laxity measured by means of the KT-1000 was 5.8 mm in case of AM bundle rupture and 4.3 mm in case of PL bundle rupture.
All the patients underwent single-bundle reconstruction of the ACL under arthroscopic assistance (one single incision technique).
In case of AM bundle repair, the type of graft used was all autologous and included bone-patellar tendon-bone in 14 cases, 4-strand hamstring tendons in 5 cases and 2-strand hamstring tendons in 3 cases.
In case of PL bundle repair, 2-strand hamstring tendons transplant was used in the 3 cases.
Postoperative side-to-side anterior laxity measured with KT-1000 averaged 0.46 mm in case of AM bundle rupture and 0.5 mm in case of PL bundle rupture.
Postoperatively, all the patients had full extension of the knee. The flexion was the same as contra lateral knee in 92 % of the cases. We had no postoperative complication.
The size of the graft was smaller than in one bundle procedures and was matched with the size of the bundle reconstucted. Peroperative technical difficulties were to preserve the healthy bundle and to drill the femoral tunnel in case of posterolateral bundle reconstruction.
The objective of this study is to determine the outcomes of meniscal suture in this group of patients.
Modern orthopaedics increasingly demands objective functional outcome assessment beyond classic scores and tests suffering from subjectivity, pain dominance and ceiling effects. Inertia based motion analysis (IMA) is a simple method and validated for gait in knee arthroplasty patients. This study investigates whether IMA assessed stair climbing can distinguish between healthy and pathological subjects and is able to diagnose a meniscal tear (MT).
Following standard physical examination (McMurray, rotation pain), 37 patients (18–72yrs) received arthroscopy suspecting a meniscal tear resulting from trauma, degeneration or both. Arthroscopy identified the presence or absence of MT and the osteoarthritis level (Outerbridge).
Prior to arthroscopy, the ascending and descending five stairs twice at preferred speed and without the use of handrails was measured using a triaxial accelerometer (62×41×18mm; m=53g; f=100Hz) taped to the sacrum. Based on peak detection algorithms, temporal motion parameters were derived such as step time up and down (Tup, Tdown), the difference between step time up and down (Tup-down), step irregularity (step time difference of subsequent steps) and step asymmetry (step time difference between affected and non-affected leg).
Patients were compared to a control group of 100 healthy subjects (17–81yrs) without any known orthopaedic pathology. Using the results of arthroscopy, test sensitivity and specificity for differentiating healthy and pathologic subjects and for diagnosing MT were calculated based on threshold values.
Sensitivity and specificity for detecting pathological motion was 0.68 (CI 0.50–0.81) and 0.92 for the most sensitive parameter (Tdown). Sensitivity and specificity to detect MT was 0.74 and 0.25 percent overall compared to 0.53 and 0.50 for the McMurray. Sensitivity increased to 1.00 when MT was combined with a chondropathy scale III or IV (McMurray 0.33).
IMA assessed stair climbing can distinguish healthy and pathological subjects and detect the presence of MT with better sensitivity than classic scores especially when combined with severe chondropathy. IMA is a simple and fast clinical outcome measure suitable for routine follow-up and may support the diagnosis of meniscal tears prior to arthroscopy.
On behalf of the Actifit Study Group: R Verdonk, P Beaufils, J Bellemans, P Colombet, R Cugat, P Djian, H Laprell, P Neyret, H Paessler,
3-D motion analysis of lumbar spinal motion in athletes, during squat weight lifting. Pressure measurement of the posterior annulus following the motion analysis study.
4 cadaveric sheep spinal motion segments mounted in purpose built jig, replicating angulation seen in the in vivo motion study. These samples were then fixed to a tension/compression loading frame, replicating the forces seen in the in vivo study. Pressure measurement was achieved using a Flexiforce single element force sensor strip, positioned at the posterior annulus.
Posterior annulus pressure was measured during axial compression and on compression with the specimen fixed at 3° of extension.
Significant decrease (p<
0.05) in flexion in all groups when lifting at 40% max was compared with lifting at 60% and 80% of max. Flexion from calibrated zero point ranged from 24.7° (40% group), to 6.8° (80% group). A progressively significant increase (p<
0.05) seen in extension in groups studied when lifting at 40% max was compared with lifting at 60% and 80% max lift. Extension from a calibrated zero point ranged from − 1.5° (40% group), to − 20.3° (80% group). No statistically significant difference found between motion seen when performing the exercise as a ‘free’ squat or when lifting using a support belt in any group studied. Initial uniform rise in measured pressure readings to a pressure of 350–400N, in the axially loaded and extension loaded specimens. Pressure experienced by the axially loaded group then gradually dropped below the pressure exerted by the loading frame, while the pressure experienced in the posterior annulus of the extension loaded specimens progressively increased.
Comparing axially loaded specimens with specimens loaded in extension, there was an average increase in pressure of 36.4% in the posterior annulus, when the spine was loaded in 3° of extension at a pressure equivalent to the 80% lift in the in vivo motion study, in comparison to axial loading.
For the medial meniscus, the mean coincidence of insertion area and tunnel footprint was 88.4 ± 15.5 % for the anterior horn insertion and 60.3 ± 31.6 % for the posterior horn insertion. The mean distance between the borders of insertion area and tunnel footprint was 0.8 ± 0.8 mm for the anterior horn insertion and 2.1 ± 1.4 mm for the posterior horn insertion.
There is little in the literature reporting on the incidence of heterotopic ossification (HO) after hip resurfacing arthroplasty. HO has long been recognized as a complication of THA, with a reported incidence that ranges between 5 – 90 %. We investigated the incidence of HO in a group of hip resurfacing patients, and compared this against the incidence of HO in a comparable group of patients managed with a conventional THA. We retrospectively reviewed patients who had a hip resurfacing procedure from January 2004 to December 2007 carried out by a single surgeon. To act as our comparative group, we selected a closely matched group of patients in terms of age and sex who underwent a THA over the same time period, under the same surgeon. 47 cases of resurfacing, 23 were female and 24 male. The 47 cases of the selected THA group consisted of 24 females and 23 males. Therefore the two groups were of a similar sex make up. Within the resurfacing group of patients, the ages ranged from 31 to 68 years, with the mean being 55.4 years, and the median being 56.5 years. The THA group possessed an age range of from 31 to 68 years, with the mean being 55.4 years, and the median being 56.5 years. The resurfacing group of patients had 5 cases showing HO, giving an overall rate of 10.6 percent. 3 were of the grade I variety, while 2 were grade II. The THA group had 6 cases showing HO, giving an overall rate of 12.8 percent. 5 of these were of the grade I variety, while 1 was of the grade III variety. We used a two tailed Fischer’s Exact test set at the 5th percentile significance level to compare the overall rate of HO occurrence between the 2 groups, namely 10.6 percent versus 12.8 percent. This gave a p value of 0.238. Therefore we can state that there is no significant difference in the rate of HO formation between the resurfacing and THA patients.
Ceramic-on-ceramic bearing is an attractive alternative to metal-on-polyethylene bearing due to the unique tri-bological advantages of alumina. However, despite the long-term satisfactory results obtained so far in the vast majority of patients, failure may occur in a few cases.
Clinical, radiographic, laboratory and microbiological data of 30 consecutive subjects with failed alumina-on-alumina total hip arthroplasties (THA) were analyzed to define if foreign body reaction to wear debris may be responsible for periprosthetic bone resorption, as in conventional metal-to-polyethylene bearings. In all cases, clinical and radiographical material was reviewed, retrieved implants were examined, and histology of periprosthetic tissues was analyzed. Massive osteolysis was never observed. Apart from 5 five patients for which revision surgery was necessary due to the occurrence of late infection, in all other cases failure had occurred due to secondary implant instability (as in the case of screwed sockets, 19 cases) or to malpositioning of the implant (5 cases). One patient suffered from chronic dislocation.
In the vast majority of cases, ceramic wear debris was absent or scarce, and did not induce any tissue reaction. In a few cases with severe wear, debris was evident in clusters of perivascular macrophages, notably in the absence of foreign body multinucleated cells, confirming the excellent biocompatibility of ceramics.
These findings indicate that wear debris and peri-prostetic bone resorption were the effect rather than the cause of failure, differently from revised metal-on-polyethylene bearings, in which foreign body cell reaction is the main pathogenetic mechanism of failure. On the contrary, mechanical problems, due to incorrect surgical technique or to inadequate prosthetic design, may cause instability of the implant, in turn resulting in wear debris production and moderate if any biological reaction.
Increasing numbers of young people receive metal on metal (CoCr on CoCr) total hip replacements. These implants generate nano-particles and ions of Co and Cr. Previous studies have shown that micro-particles, nano-particles and ions of CoCr cause DNA damage and chromosomal abberrations in human fibroblasts in tissue culture, and in lymphocytes and bone marrow cells in patients with implants. Several surgeons have used these implants in women of child-bearing age who have subsequently had children. Significantly elevated levels of cobalt and cromium ions have been measured in cord blood of pregnant women with CoCr hip implants. The MHRA (Medicines and Healthcare products Regulatory Agency) subsequently stated that there is a need to determine whether exposure to cobalt and chromium represents a health risk during pregnancy.
In an attempt to investigate this risk, we used a well established in vitro model of the placental barrier comprised of BeWo cells (3 cells in thickness) derived from the chorion and exposed this barrier to nanometer (29nm) and micron (3.4μm) sized CoCr particles, as well as ions of Co2+ and Cr6+ individually or in combination. We monitored DNA damage in BJ fibroblasts beneath the barrier with the alkaline gel electrophoresis comet assay and with γH2AX staining.
The results showed evidence of DNA damage after all types of exposure. The indirect damage (through the barrier) was equal to the direct damage at the concentrations tested. The integrity of the barriers was checked with measurements of electrical resistance (TEER values) and permeability to sodium fluorescein (376Da) and found to be intact.
In light of these results and with the knowledge that BeWo cells express the transmembrane protein Connexin 43, we tested the theory that a damaging signal was being relayed via gap junctions or hemi channels in the BeWo cells to the underlying fibroblasts. We used the connexin mimetic peptides Gap19 and Gap26 (known to selectively block hemichannels and gap junctions respectively) and 18α-glycyrrhetinic acid (non-selective gap junction blocker). All of these compounds completely obliterated the indirect damaging effect seen in our previous experiments.
We conclude that CoCr particles can cause DNA damage through a seemingly intact barrier, and that this damage occurs via a bystander mechanism. It would be of interest to test whether this is simply a tissue culture effect or could be seen in vivo.
Although suction force may have a benefit in reducing the risk of dislocation, it may prevent lubricant recovery between the bearings and will influence the sliding resistance. If the suction force is too high, the head and cup can be held together such that the recovery of synovial fluid is restricted or impossible, even when the hip is not loaded during the swing phase. Both the clearance and the viscosity have a significant effect to determine the suction force and the lubrication of MOM hip joints. It is concluded that suction force is a factor to be considered during the selection of MOM hip joint clearance.
Femoral stress shielding in cementless THA is a potential complication commonly observed in distally loading press-fit stems. This prospective study describes long-term femoral bone remodeling in cementless THA at a mean of 17 years (range: 15 to 20) in 208 consecutive fully HA-coated stems (Corail, DePuy Int. Ltd, Leeds, UK). All THA were performed by one group of surgeons between 1986 and 1991. The concept of surgical technique included impaction of metaphyseal bone utilizing bland femoral broaches until primary stability was achieved without distal press-fit. Radiographic evaluation revealed a total of five (2.4%) stems with periprosthetic osteolysis, which were associated with eccentric polyethylene wear. They were either revised or awaiting revision surgery. The remaining 97.6% stems revealed biologic load transfer in the metaphysis alone (52%) or in both metaphysis and diaphysis (48%). Stem survival of 97.6% after 15 to 20 years without stress shielding were considered to be related to: impaction of metaphyseal bone, bland broaches, HA coating, and unique prosthetic design.
Ceramic-on-metal (COM) bearings have shown reduced wear and friction compared with metal-on-metal (MOM) bearings in-vitro. Lower wear has been attributed to a reduction in corrosive wear, smoother surfaces, improved lubrication and differential hardness reducing adhesive wear. Clinical studies have also shown reduced metal ion levels in-vivo compared with MOM bearings. The aim of this study was to examine two explanted COM bearings (one head and cup, one head only), and to assess the effect of in-vivo changes on the wear performance of the COM bearings by comparing the wear of the explanted bearings with three new COM implants in a hip wear simulator.
Two 28mm diameter COM bearings were provided for analysis. These were visually examined and surface profilometry was performed using a 2-D contacting profilometer (Form Talysurf, Taylor Hobson, UK). Scanning electron microscopy was used to image the regions of transfer on the ceramic heads, and EDX to assess the transfer composition (Philips XL30 ESEM).
Hip simulator testing was conducted for 2 million cycles (Mc) comparing the explanted bearings with three new 28mm COM bearings. Tests were performed in a Prosim simulator (SimSol, UK), which applied a twin peak loading cycle, with a peak load of 3kN. Flexion-extension of − 15 to 30 degrees was applied to the head and internal-external rotation of +/− 10 degrees was applied to the cup, components were mounted in the anatomical position. The lubricant was 25% (v/v) calf serum supplemented with 0.03% (w/v) sodium azide and was changed approximately every 0.33Mc. Wear was measured gravimetrically at 0.5, 1 and 2 Mc.
Regions of material transfer, identified on both ceramic explant heads, were shown to be CoCr material by EDX analysis, suggesting metallic transfer from the metal cup. Profilometry traces across metallic transfer showed comparable surface roughness measurements compared to unworn material.
The overall mean wear rate for the new COM bearings at 2Mc was 0.047 ± 0.06mm3/Mc. The mean wear rate for the explanted head articulated with a new cup was slightly lower at 0.034mm3/Mc. The mean wear rate for the explanted head and cup was highest at 0.15mm3/Mc. It was noted that the explanted head/cup had higher bedding in wear compared with the other bearings, but still significantly less than a new MOM bearing (mean bedding-in wear rate 2.03 ± 2.59 mm3/Mc). The steady-state wear was comparable with the new bearings. As the orientation of these implants in-vivo was unknown, it is proposed that the elevated wear during bedding-in of the explanted head/cup bearing may be due to the alignment of the components. The wear rates of the explanted ceramic head against a new cup were comparable with the new bearings, suggesting that the presence of metallic transfer on the ceramic head does not adversely affect the wear behaviour of COM bearings.
Highly cross-linked polyethylene (HXLPE) is one of the most widely utilized bearing surfaces for total hip arthroplasty (THA). The first patients to receive XLPE will be 10 years post-op as of December 31, 2008. The purpose of this study is to report the long-term clinical and radiographic outcomes of patients implanted with HXLPE.
A group of 247 primary total hip replacements (224 patients) using HXLPE liners (Longevity or Durasul, Zimmer Inc.) with 22, 26, 28, or 32mm femoral heads were implanted between 1999 and 2001. Clinical evaluation measures included the Harris hip, EQ-5D, SF-36 functional scores, and UCLA activity scores. In addition to plain radiograph assessment, the computerized Martell method was used to measure head penetration over time. A matched group of 241 primary total hip replacements (201 patients) with the same head sizes using conventional polyethylene (PE) with a minimum of 7 years follow-up was used as a Martell method control group. The steady state penetration rate was defined as the slope of the linear regression line of the plot of head penetration from the 1 year film to each subsequent film to discount the early bedding-in process. A student’s t-test was used to compare wear rates between head sizes in each group, and a repeated-measures mixed model ANOVA was used to compare the groups for the 28mm head size.
There were no osteolytic lesions around the cup or stem, and no revisions were performed for polyethylene wear or liner fracture. Clinical outcome scores were averaged: Harris Hip 88.1±11.97, EQ-5D 74.0±27.0, SF-36 physical activity scores 53.3±8.4, SF-36 mental score 46.9±11.1, and UCLA activity 6.4±2.1. The steady state wear of the conventional polyethylene patients increased with time for both 26 and 28mm head sizes (0.144 and 0.127mm/year, respectively). No significant difference was found between the head sizes coupled with conventional polyethylene (p=0.14). Femoral head penetration in the highly cross-linked polyethylene did not increase over time after the first year. The steady state wear rates of HXLPE liners with 28mm or 32mm femoral heads were not significantly different than a slope of zero (p=0.54 for both head sizes).
Clinical follow-up results are typical of a primary THR patient population, and the radiographic results are excellent with no signs of peri-prosthetic osteolysis. Patients with PE show wear rates that are significantly different than zero indicating significant wear of the material. Conversely, patients with HXLPE display no measureable wear at 7–9 years as the wear rates were within the error detection of the Martell method. This long-term clinical and radiographic follow-up study for this new bearing material shows excellent clinical outcomes with very low in vivo wear.
The Harris Hip Score improved from a pre-operative mean of 56.99 to 97.12 at the latest follow up, and 60% of patients were scored at 100. At the latest follow up, 91% of patients scored 6 or above on the UCLA activity score; indicating at least regular participation in moderate exercise.
There were no dislocations and no clinically evident DVT’s or PE’s
There have been 11 revisions for fracture (1.06%). Five of these were intra-operative fractures, and six of these took place in patients aged over 50years. Fractures occurred in 3.1% of patients 65 years or more and in 0.5% of patients under 65 years(P< 0.05). In addition there were three revisions for cup loosening (0.29%) all in women over 60 years, three for unexplained pain (0.29%), one for impingement and subluxation, and one for infection(0.1%) Five patients have died with the resurfacing in situ (0.51%), for unrelated causes.
The 3-year cumulative survival rate for all patients and all components was 97.4%. For 425 patients under 55 years the cumulative survival rate was 99.4%, aged under 65 years was 98.3%, and aged over 65 yrs was 94.8 %.
Restoration of the height of the flattened portion of the weight-bearing surface of the femoral head reduces abnormal loading of the acetabular articular cartilage by improving congruency of the joint.
At a minimum of 3 year follow up both patients had sustained improved range of movement, pain and Oxford hip score. Repeated imaging shows no evidence of joint space narrowing or loosening at this stage.
The difference in the mean values regarding inclination was greater than would be expected by chance; there was a statistically significant difference (P = 0,010).
Navigation technique was discussed to equalize the drawback of MIS. However, tools like imageless navigation may further improve the cup position even in traditional approach.
There is a known association between femoroacetabular impingement (FAI) and osteoarthritis of the hip. What is not known is whether arthroscopic excision of an impingement lesion can significantly improve a patient’s symptoms.
This study compares the one-year results of hip arthroscopy for cam-type FAI in two groups of patients. The study (osteoplasty) group comprised 24 patients (24 hips) with cam-type FAI who underwent arthroscopic debridement with excision of their impingement lesion. The control (no osteoplasty) group comprised 47 patients (47 hips) who underwent arthroscopic debridement without excision of their impingement lesion. In both groups, the presence of FAI was confirmed on pre-operative plain radiographs. The modified Harris hip score (MHHS) was used for evaluation pre-operatively and at one year’s follow-up. Non-parametric tests were used for statistical analysis.
A tendency towards higher median post-operative MHHS scores was observed in the study than in the control group (83 vs. 77, p = 0.11). This was supported by a significantly higher portion of patients in the osteoplasty group with excellent/good results (83% vs. 60%, p = 0.043). It appears that even further symptomatic improvement may be obtained after hip arthroscopy for FAI by means of the femoral osteoplasty. When treating cam impingement arthroscopically, both central and peripheral compartments of the hip should always be accessed.
Kaplan-Meier analysis showed a ten-year survival rate of 87% (95%C.I. 73.1–100%) with end point acetabular revision for any reason and 95% (95%C.I. 86.2–100%) with end point acetabular revision because of aseptic loosening. The mean preoperative HHS was 55 points and improved to 72 points postoperative.
The adult congenital hip dislocations and dysplasias have been previously classified by Eftekhar, Crowe et al., Hartofilakidis et al., Kerboul et al. and Mendes et al. The most conventient and widely used one is the Hartofilakidis and Crowe classification. Three different types of congenital hip disease in adults have been distinguished by Hartofilakidis and et al. based upon the position of the femoral head relative to the acetabulum: dysplasia; low dislocation; and high dislocation. All these classification systems are only radiological and does not highlight the operative technique in detail and the complications that we can observe perioperatively. Our classification system is also a radiological classification system but more useful for predicting the difficulty of the operative procedure and selecting the right operative method. In our classification system; at type I; dysplasia and less than 25% subluxations, we divided type I in to three subgroups, at type Ia, only dysplastic acetabulums, at type Ib, with elephant’s trunk type osteophyte formation and at type Ic, curtain type osteophytic formations, we included dysplasia and less than 25% subluxations in the same group because of operative technique similarities. At type 2; subluxations between 25% and 75%, we divided type II in two subgroups according to the angle between the inner margin of the teardrop and superior border of the acetabulum, at type IIa, the angle is less than 60°, at type IIb, the angle is greater than 60°, it’s important to show femoral allogreft usage requirement, at type 3; subluxations greater than 75%, at this type there will be no need of femoral allogreft usage but extra-small reamer usage for forming a suitable acetabular bed. At type 4; luxations greater than 100%, we also divided type IV in to two subgroups accordind to the distance between superior margin of true acetabulum and trochanter major line, at type IVa, < 2.5 cm, at type IVb, > 2.5 cm. It’s also important to make the decission of shortening. To form this classification three observers with different levels of training independently classified 412 dysplastic hips (operated between1995 and 2005) on 380 standard anteriorposterior pelvis radiographs, retrospectively according to the criteria defined by us. To assess intraobserver reliability, the measurement was repeated 3 months later. Statistical analysis was performed by calculating the weighted kappa correlation coefficient. System showed good inter- and intraob-server reliability for use in daily practice. Eventually, we determined a significant correlation between the aplied surgical procedures and classification. As a conclusion, we believe that our classification system of osteoarthritis secondary to developmental dysplasia of the hip in adult patients guides the surgical procedure more effectively than the other classification systems.
Collarless, polished and tapered cemented stems are nowadays commonly used in hip surgery. Normally, a hollow centralizer is applied to the stem tip to allow the prosthesis to sink in the cement mantel in the event of creep and loosening between stem and cement. It is believed that in this way the stem will stabilize and regain its tight bond with the cement. The prosthesis MS-30 (Zimmer) is collarless, polished and triple tapered and has a hollow centralizer, but was previously used with a solid centralizer. We hypothesised that these types of stems, exemplified by the MS-30, used with a hollow centralizer would sink more but stabilize better, become more stable in the important rotational migration and retrovert less than with a solid centralizer. In a prospective, controlled clinical study we randomised 60 patients with primary coxarthrosis into either hollow or solid centralizer used with the MS-30 stem. The effect was evaluated for a 2-year follow up period by repeated RSA examinations, conventional radiographs and clinical follow-ups with the questionnaires WOMAC, SF-12 and Harris Hip Score.
The RSA results showed small early migration in both groups and almost all of it occurred within the cement mantle, i.e. between stem and cement. The group with hollow centralizers migrated distally significantly more than the group with solid centralizers (p< 0.0001) (1.40 mm vs 0.28 mm). In rotation, however, there was no difference (retroversion 0.99° and 0.94°). Neither was there any difference regarding clinical outcome and questionnaires.
As expected the group with hollow centralizers migrated more distally, in the same magnitude as reported in earlier RSA studies for the conceptually similar prostheses Exeter and C-stem. Interestingly, there was no difference regarding the rotational behaviour, and both groups showed less retroversion than reported in the earlier reports. MS-30 seems to have a design that regardless of centralizer type well withstands rotational motion within the cement mantle. This study cannot fortify the need for a hollow centralizer for this collarless, polished and triple tapered prosthesis.
Despite great progress in implant design, materials and new implantation techniques aseptic loosening is still the most frequent cause of implant failure in THA, which was found to be increased especially in patients with osteonecrosis of the femoral head (ON-FH). While a direct link between aseptic loosening and periprosthetic bone loss still remains elusive, there is plentiful evidence for a close association with early migration of implant components. Although the beneficial effect of bisphonates on periprosthetic bone mass is well established, little is known to date about their effects on implant migration. This is an important issue, because successful prevention of early implant migration would provide strong evidence of a beneficial effect on the survival rate of THA. Previously, Krismer et al. found that a total migration of the cup of ≥ 1mm and a subsidence of ≥ 1.5mm 2 years after surgery was highly predictive for aseptic implant failure of THA within 8 to 10 years.
Fifty patients with end-stage ON-FH were consecutively enrolled to receive either 4mg of ZOL or saline solution (CTR) in a double-blind fashion. Radiographs standardized for EBRA-digital analysis were performed at each follow-up exam at 7 weeks, 6 months, 1 year, and yearly thereafter. The minimum follow-up period was 2 years (median follow-up: 2.8 years). Migration of the acetabular and femoral components was analyzed with the EBRA-digital software (University of Inns-bruck, Austria) independently by 3 investigators fully blinded to randomization.
Within the placebo group, distal migration of the stem (subsidence) steadily increased up to −1.2mm ± 0.6 SD at 2 years after THA without reaching a plateau phase (P< 0.001, Friedman ANOVA). Less but a nearly curvilinear migration pattern was found for the acetabular components, with a transverse migration of 0.6mm ± 1.0 SD and a vertical migration of 0.6mm ± 0.8 SD at 2 years (P< 0.001, Friedman ANOVA). Treatment with ZOL effectively minimized the migration of cups in both the transverse and vertical direction (0.15 mm ± 0.6 SD and 0.06 mm ± 0.6 SD, respectively, P< 0.05, ANOVA), and a trend to a decreased subsidence was also found for stem migration (−0.91 mm ± 0.51 SD; P=0.11, ANOVA). In addition, total cup migration exceeding 1mm at 2 years was significantly reduced by ZOL in 8 patients (12 vs 4 in CTR vs ZOL, respectively) as was also found in 6 patients for subsidence (≥ 1.5mm in 9 vs 3 patients in CTR vs ZOL, respectively) (P< 0.05, Fisher’s exact).
This is the first clinical trial reporting that a single infusion of ZOL suffices to improve initial implant fixation in THA. Based on best evidence available to date, this new concept shows great promise of improving the long-term outcome in THA and should be given attention in long-term trial.
Cross-linked PE theoretically allows the use of thinner inserts and larger diameter heads than UHMWPE. This participates in reducing the risk of dislocation. Durasul® liners have demonstrated improved wear performance over UHMWPE in laboratory testing. This may also result in lower migration and loosening rates of the implants.
Our first aim was the assessment of linear wear of Durasul® inserts associated with Protasul® 36 mm CoCr prosthetic heads. We compared the results with our data on 28 mm CoCr and Biolox heads.
The first hypothesis was that Durasul® inserts combined with a 36 mm CoCr head would not produce more wear than would Durasul® inserts in association with a 28 mm CoCr prosthetic head.
The second hypothesis was that Durasul® inserts combined with a 36 mm head could even produce less wear than a UHMWPE liner in association with a Biolox® 28 mm prosthetic head.
The second aim was to correlate cup migration with polyethylene wear rate.
111 patients (37 men, 74 women) with a median age of 74 years (range: 54–90) received Durasul® liners in an Allofit Ti cup and Protasul® 36 mm heads. They were followed for minimum 5 years.
16 patients with a Durasul® liner received a 28 mm Protasul® head (control A) and 40 received a UHMWPE liner combined with a Biolox® 28 mm head (control B).
Patient outcome was assessed with the HHS. PE wear assessment was performed using a specific analysis model created in the Imagika® software. Cup migration was evaluated using the EBRA-CUP® software.
The preoperative and last follow-up HHS were 50.4+/−10.5 and 97.5+/−5.5 respectively.
The bedding-in penetration of the prosthetic head were 0.054+/−0.009 mm (Durasul®, 36 mm CoCr head), 0.056+/−0.008 mm (Durasul®, 28 mm CoCr head) and 0.057+/−0.010 mm (UHMWPE, Biolox® 28 mm head). There were no significant differences between the different groups.
The annual linear wear rates were 0.029+/−0.003 mm (Durasul®, 36 mm CoCr head), 0.032+/−0.014 mm (Durasul®, 28 mm CoCr head) and 0.087+/−0.056 mm (UHMWPE, Biolox® 28 mm head). There were no significant differences between Durasul® groups, but a P value of 0.00027 was observed between the study group and the control B group.
We didn’t observed cup migration in our patients (0.09 mm medially and 0.13 mm cranially).
Patient satisfaction was high with improvement of quality of life.
Combined with the Durasul® inserts used in this series, 36 mm CoCr prosthetic heads had no unfavourable influence on the wear assessment compared with the use of 28 mm prosthetic heads. The annual linear wear rate of Durasul® liners was 37.84% of that seen with the UHMWPE liner. The absence of cup migration at last follow-up may indicate very low PE wear rates.
Lever-out-moments of 17 Nm were determined for both the PMI- and composite-model for the female surgeon using the PSL cup, whereas 27 Nm and 70 Nm, respectively, were reached for the EP-FIT shell.
For the male surgeon using the PSL cup, lever-out moments of 15 Nm and 30 Nm for the PMI- and composite-model respectively were determined. Insertion of the EP-FIT cup resulted in lever-out moments of 10 Nm using the PMI-model and 82 Nm using the composite-model.
The low machined insertion force led to average lever-out moments of 34 Nm for the PSL and 71 Nm for the EP-FIT cups using the composite-model. For the high machined force, the highest lever-out moments of 44 Nm and 99 Nm for the PSL and EP-FIT shells respectively were determined.
Very good functional results were obtained with an improvement of the mean Merle d’Aubigné score from 9.5 ± 2.0 at baseline to 15.0 ± 3.1 at follow-up, and 86% excellent or good results (McNab score). Satisfaction with treatment outcome was high, and 96% of patients would recommend the performed procedure to a friend.
This experimental study aimed to determine the pattern of load transmission to the cement mantle and to the outer surface of six composite femurs implanted with three different designs of polished, collarless, tapered stems (2 specimens for each type), before and after the removal and reinsertion of the same stem. Strain distribution was measured with uni-axial and tri-axial strain-gauges before, after implantation and after reinsertion of the stems. Additionally, axial and rotational stability of the stem relative to the cement mantle and to the composite were determined by means of one extensometer and two linear variable displacement transducers (LVDT’s). All specimens were loaded simulating single leg stance of 3,25 body weight for a 708N subject. Static load were applied to the intact femurs, after implantation, after cyclic loads of 1Hz up to 3x10 5 cycles followed by 7Hz up to 1million cycles, and after reinsertion. Variation of strain and micro-motion during static loading following reinsertion were determined by the average of 10 cycles, with each cycle being represented by the difference between maximum and minimum values.
Linear regression analysis of the strain values obtained by the sensors in the cement mantle after reinsertion plotted with regard to the strains obtained initially by the same sensors before and after cyclic loading showed coefficients R2= 0.95; 0.91,with slopes of 1.12 and 1.03 respectively. The values of static strain of all sensors plotted with regard to values of initial static strain showed a very strong positive correlation (R2 = 0.98; slope = 0.96).
These findings support the concept that reinsertion of same design and size polished, collarless tapered stems may not alter the pattern of load transmission and stability at the interfaces between stem/cement, and cement/bone to the outer surface of bone. The mechanical conditions at the interfaces are restored with no need for additional cement during reinsertion if the cement envelope is preserved. The same mechanical principle that maintains the stability of the stem during subsidence for ”force-closed” fixation, may keep the stability of the interface following reinsertion. For these reasons this procedure may not be applicable to designs with texturing or pre-coating, and cylindrical-collared designs because in such conditions (“shaped-closed “fixation) the mechanics of stem/cement interface may not be restored.
a proper randomized controlled trial; based on a total hip prosthesis with or without hydroxyapatite-coating with one identical geometry; primary uncemented total hip arthroplasty; and used objective, validated clinical and radiographic outcome measurements.
The aim of this retrospective study was to compare full blood cobalt-chrome levels, patient activity, clinical/radiological outcome and implant survival in patients with osteonecrosis and osteoarthritis after a minimum follow up of 12 years.
Metal on metal THA seems to be an effective and safe treatment option for these patients.
Metal on Metal Hip Resurfacing Arthroplasty (MoMHRA) has gained popularity due to its perceived advantages of bone conservation and relative ease of revision to a conventional THR if it fails. Known MoMHRA-associated complications include femoral neck fracture, avascular necrosis/collapse of the femoral head/neck, aseptic loosening and soft tissue responses such as ALVAL and pseudotumours. This study’s aim was to assess the functional outcome of failed MoMHRA revised to THR and compare it with a matched cohort of primary THRs.
Polyethylene (PE) wear particle induced osteolysis remains a major cause of failure in total hip arthroplasty (THA), so that routine clinical measurement of wear stays important. Crosslinked PE promises very low wear rates so that measurement accuracy becomes increasingly important to distinguish alternative materials. The rising use of large femoral heads causes lower linear head penetration also requiring improved accuracy. Digital x-rays and wear measurement software have become standard, but during archiving and exchange of x-rays, image format, resolution or compression are often changed without knowing the effects on wear measurement. This study investigates the effect of digital x-ray resolution and compression on the accuracy of two software programs to measure wear.
The 8-year post-op digital x-rays of 24 THA patients (Stryker ABG-II, 28mm metal femoral head against Duration or conventional PE) were taken from the hospital PACS (Philips Diagnost H, AGFA ADC Solo, Siemens Medview) as DICOM at 5.1 MPix resolution. Images were converted to compression-free TIFF format using Irfanview V4.1. Wear (linear head penetration) was measured using Roman V1.7 and Martell Hip Analysis Suite 7.14. The x-rays were smoothened (Irfanview V4.1, Median Filter: 3) as recommended in literature for compatibility with Martell’s edge detection algorithm. Wear was measured twice by two independent observers at original format and resolution and then once by a single observer at three subsequently halved resolutions (2.6, 1.3, 0.65MPix) and three jpeg compressions (90%, 50%, 20%). Intra- and inter-observer reliability (R) was compared to the reliability of measuring manipulated images (Pearson’s r). The mean absolute wear differences (AD) were calculated versus the original x-ray.
The mean total wear was 0.98+/−0.59mm (0.3–2.4mm) equaling an annual of wear rate of 0.11mm/yr. Using Roman, Intra-R (0.97) and Inter-R (0.96) were high and AD low (0.10 and 0.20mm). Reduced image resolution caused the R to drop only slightly to 0.95 (2.6MPix), 0.92 (1.3MPix) and 0.94 (0.65MPix) while AD remained low (< 0.20mm). Also compression hardly affected R (90%:0.96, 50%: 0.94, 20%:0.93) nor AD (< 0.20mm). Using Martell Intra-R (0.99) and Inter-R (0.87) were also high but dropped with reducing resolution (0.82, 0.72, 0.34, AD: 0.4–1.1mm) but hardly with increased compression (0.95, 0.92, 0.94, AD< 0.20mm).
Low resolution and high compression do not have to be critical for wear measurement accuracy and reliability when edge detection is performed by a trained human eye. This way interpolating the ball and cup perimeters and locating their centers can be performed at accuracy below pixel size (ca. 0.40mm at 0.65MPix). Automatic edge detection is less robust to reducing resolution but performs at high compression. If image size needs to be reduced compression is preferable to reducing resolution.
Sectioned femoral components retrieved from failed hip resurfacing arthroplasties show resorption of proximal femoral bone or formation of a fibrous membrane at the bone cement interface. We hypothesize that both scenarios create a functional discontinuity zone (FDZ), which exacerbates off-loading the proximal bone and promoting resorption. Our study uses Finite Element (FE) modeling to examine the effects of the presence of an FDZ on bone remodeling following hip resurfacing arthroplasty. A radiographic analysis of the proximal femur following hip resurfacing was conducted in order to draw a comparison to clinical findings
The hip resurfacing FE models were oriented in variable angles and a low-modulus (2 MPa) FDZ was simulated beneath the implant head. Femoral joint and muscle loads were applied. Interface stress was compared for the normal and simulated FDZ resurfaced femurs. Bone remodeling stimuli was determined using changes in strain energy. A range of implant orientations were compared to study the affect on bone remodelling. A retrospective radiological analysis was undertaken on 100 hips with a minimum of 5 years follow up. Measurements of femoral neck diameter at 2 and 5 years were undertaken.
The presence of the simulated FDZ in the FE analysis resulted in increased proximal-medial bone resorption and slightly greater bone formation surrounding the stem. Correspondingly, device-bone interface stresses were found to decrease proximally under the loading platform and increase at the stem, particularly adjacent to the stem-head junction. Valgus orientation showed increased resorption underneath the shell. Varus orientation showed increased bone formation at the stem tip. The radiological analysis identified 2 distinct patterns of neck thinning. Slow thinners (76%) had less than 5% reduction in neck diameter at 2 years and less than 10% at 5 years. Rapid thinner (24%) had more than 5% thinning at 2 years and more than 10% at 5 years. The mean reduction in neck diameter was signifanctly different between the two groups at the two time points (p< 0.01). The rapid group had a higher proportion of valgus aligned implants (88%) and a significant decrease in reconstructed offset (p=0.0023).
The FE results support the hypothesis that the presence of a FDZ decreases load transfer to the proximal bone, resulting in increased medial stress shielding and resorption. These results are consistent with the radiological findings. In order to better understand the cause of resurfacing implant failures, additional retrieval studies are necessary.
Early revision is an important risk factor for repeated revision and poor results after primary total hip replacement and instability is a major cause of early revision. Larger articulations with cross-linked polyethylene are proposed as a solution, but these are not without risk, including fracture of the thin polyethylene rim of the liner. The aim of our study was to examine implant-related revisions among primary total hip replacement patients with up to six year follow-up in a randomized controlled trial which compared 28 mm and 36 mm metal on highly cross-linked polyethylene articulations in total hip replacement.
557 patients undergoing primary total hip replacement were included in this study. Risk factors for dislocation and wear were controlled by stratification and patients were then randomized intra-operatively to either a 28 or 36 mm articulation.
To date, 10 hips have been revised for implant-related problems following primary total hip replacement. Seven hips with a 28 mm articulation were revised to a larger articulation because of instability. Four of these were for recurrent dislocation, one for an irreduceable first dislocation and two for subluxation. In contrast, only one patient who had undergone total hip replacement with a 36 mm articulation was revised for recurrent dislocation. One hip with a 36 mm articulation in a well-positioned cup was revised to a 32 mm articulation because of elevated lip liner fracture. Another 36 mm articulation hip was revised for acetabular component loosening.
This study shows that a 36 mm metal on highly cross-linked polyethylene articulation reduces the need for early revision for instability after primary total hip replacement. However, these benefits need to be weighed against the potential risks associated with these articulations, including rare fracture of the relatively thin poly-ethylene liner.
Large articulations using cross-linked polyethylene and other alternate bearings are increasingly being used to reduce the incidence of dislocation, the most common early complication following total hip replacement. While indirect evidence has suggested the potential benefits of a large articulation in reducing dislocation risk, this has not been proven in a well-controlled clinical trial. The primary objective of our multi-centre international randomized controlled trial was to compare the one-year incidence of dislocation between a 36 mm and 28 mm metal on highly cross-linked polyethylene articulation in primary and revision total hip replacement.
644 patients were entered into the study. Patients were stratified according to a number of factors which may influence dislocation risk, including primary or revision total hip replacement, age, sex, Charnley grade, diagnosis and stem type. Patients were randomized intra-operatively to either a 28 or 36 mm articulation.
The 12-month incidence of dislocation was statistically significantly lower in patients undergoing total hip replacement with a 36 mm articulation than in those with a 28 mm articulation (1.3% vs 5.2%, p< .05). A total of 6 dislocations occurred in the 4 patients who dislocated with a 36 mm articulation, compared to a total of 36 dislocations in the 17 patients who dislocated with a 28 mm articulation. When primary and revision THR were examined separately, the 12-month incidence of dislocation was statistically significantly lower in patients undergoing primary total hip replacement with a 36 mm articulation than in those with a 28 mm articulation (0.7% vs 4.2%, p< .05). A total of 4 dislocations occurred in two patients with a 36 mm articulation, compared to a total of 19 dislocations in 12 patients with a 28 mm articulation. The incidence of dislocation after revision total hip replacement with a 36 mm articulation was 4.8%, compared to 11.1% with a 28 mm articulation.
This large randomized study unequivocally shows for the first time that, compared to a 28 mm articulation, a 36 mm articulation in total hip replacement is efficacious in reducing the incidence of dislocation in the first year following hip replacement.
The aim of this study was to improve the preopera-tive care of hip fracture patients.
Ludloff’s medial approach has never been used for other hip surgeries especially not for THR.
47 patients (26 men/21 women) provided informed consent to participate in the study. The inclusion criterion for the study was the diagnosis of osteoarthritis of the hip joint. The average age at operation was 53.7±10.4years. All patients were provided with a CUT® prosthesis.
All patients were examined clinically and X-rayed preoperatively as well as postoperatively at three days, two weeks, six weeks and six months. The functional hip scores according to Harris and the Oxford hip score were obtained preoperatively and at the defined intervals postoperatively. The surgical duration and the intraop-erative as well as the postoperative blood loss were measured for each patient. Abductor muscle function and the number of steps a patient was able to walk without walking aids on a treadmill at a velocity of 5km/h (a maximum of 100steps was measured) were assessed.
Multifactorial analyses of variance and Chi-square tests were performed.
Based on the numbers available there were no significant differences between the two groups in the distribution of patient age (p=0.604), gender (p=0.654), weight (p=0.180) and height (p=0.295). No significant differences in the calculated Harris score (p=0.723) were found pre-operatively. The amount of steps the patient was able to walk was not different between the approach groups (p=0.636).
The total amount of blood loss (intra- + post-OP) was even significantly lower in the medial approach group (p=0.009).
Three days post-operatively the leg lengths were assessed. The difference was not statistically significant based on the numbers available (p=0.926). The overall correlation between Harris and Oxford score was significant (r2=0.63, p< 0.001).
Three days post-operatively a slight, but significant better Harris (p< 0.001) and Oxford scores (p=0.001) could be observed in the medial approach group. The number of steps the patient was able to walk without help or crutches was significantly higher in the medial approach group (p=0.001). The Trendelenburg sign (p< 0.001) and the limping criterion (p< 0.001) were significantly less in the medial approach group.
Two weeks post-operatively the Harris (p=0.001) and the Oxford (p=0.046) scores were significantly better for the medial approach group. The number of steps the patient was able to walk without help or crutches was significantly higher in the medial approach group (p< 0,001).
The medial approach is clinically feasible to perform the implantation of a femoral neck prosthesis. The accuracy of the stem implantation reflected in both the leg lengths and the postoperative X-ray alignment was not different between the groups.
After six months there was no significant difference between the conventional anterolateral approach and the medial approach in the presented study.
9,596 of the 280,201 primary THRs, had been revised. Ten-years survival was 91.9% (95% CI: 91.5 – 92.3) in Denmark, 93.9% (95% CI: 93.6–94.1) in Sweden, and 92.6% (95% CI: 92.3–93.0) in Norway.
In Sweden and Norway 23% of revisions were due to dislocation, compared to 34% in Denmark. Replacement of only cup or liner constituted 29% of the revisions in Sweden, 33% in Norway, and 44% in Denmark.
Surface replacement is widely used as a treatment for younger patients requiring hip replacement. However the long-term performance of such devices remains unknown. One area of concern is the viability of the bone in the proximal portion of the femur. These concerns are related to the trauma which the proximal femur is exposed to during the operative procedure and the level of vascularity which is subsequently attained. Previous studies have used a single time point and shown reduced loss in bone stock compared to total hip replacement and minimal difference with the contra-lateral unaffected hip. The aim of this study is to report the changes in bone mineral density (BMD) which take place at different time points in the same patients following implantation using DEXA scanning. The effect of component placement and metal ion levels will also be considered
A total of twenty-six patients were recruited (18 male, 5 female; 15 left hip 11 right, mean age at surgery 56 years, range 31–69) who had DEXA measurements at all three time points post-op, 120 and 420 days (4 and 14 months). Measurements were taken in the neck region and Gruen zones 6 and 7. Metal ion levels were measured in whole blood using the high resolution ICP-MS technique.
The BMD in the neck region, zone 7 and 6 post-operatively were 0.945, 1.092 and 1.451g/cm2 respectively. In the neck region BMD reduces at 120 days (96.5%) and then increases to higher than the post-op level at 420 days (103.6%, differences between all three groups: p< 0.008).
In zone 7, BMD drops at 120 days (98.2%, p=0.03) but recovers to higher than post-op levels after 420 days (101.65%)but not significantly so (p=0.13). In zone 6 there are no significant differences at any ime points.
Despite the wide variation in the immediate postoperative bone density (0.70–1.25g/cm2), there is no obvious relationship between this value and the capacity of the bone to recover from the operative trauma
Twenty-three of these patients were also part of a metal ion study previously reported. There was no relationship between the combined metal ion levels (chromium+cobalt) at 12 months and the changes in BMD in the neck region at 4 or 14 months.
There was no significant difference in the response of the male and female patients. There was no significant relationship between changes in BMD and cup abduction angles, femoral component inclination nor acetabular component diameter.
This is a short-term study, however it is reassuring that whilst BMD reduces in the neck and Gruen zone 7, by 420 days (14 months) it has recovered to postop levels and in zone 7 has exceeded the post-op levels. Furthermore this response appears to be unrelated to patient factors and component position.
While computed tomography (CT) provides an accurate measure of osteolysis volume, it would be advantageous in general clinical practice if plain radiographs could be used to monitor osteolysis. This study determined the ability of plain radiographs to detect the presence of and determine the progression in size of osteolytic lesions around cementless acetabular components.
Nineteen acetabular components were diagnosed with osteolysis using a high-resolution multi-slice CT scanner with metal artefact suppression. Mean duration since arthroplasty was 14 years (range 10–15 years) at initial CT. Repeat CT scans were undertaken over a five year period to determine osteolysis progression. On anteroposterior pelvis (AP) radiographs and oblique radiographs of the acetabulum seen on the rolled lateral hip view, which were taken at the same time as the CT scans, area of osteolysis was measured manually correcting for magnification.
Osteolysis was detected on the AP radiographs in 8 of 19 hips (42%), on the oblique radiographs in 6 of 19 hips (32%) and on the combined AP and oblique radiographs in 8 of 19 hips (42%). Throughout the study period, osteolysis was detected on 31 of 76 AP radiographs (41%) and 22 of 75 oblique radiographs (29%). Osteolysis was more likely to be detected on plain radiographs if the lesion volume was greater than 10cm3 in size (p=0.005). On CT, osteolysis progressed by more than 1cm3/yr in 10 of 19 hips (55%). In these ten hips, osteolysis progression was detected on AP radiographs in six hips and on oblique radiographs in three hips. No correlation was found between osteolysis progression measured by CT and that measured on AP (r2=0.16, p=0.37) or oblique (r2=0.37, p=0.15) or AP and oblique radiographs (r2=0.34, p=0.17).
Plain radiographs are poor in monitoring progression in size of periacetabular osteolytic lesions. Plain radiographs may detect lesions more than 10cm3 in size, but are unreliable.
Ion analysis: Serum was collected from test station and allowed to settle for 12 hours. An aliquot of 20 ml from lubricant was collected. Each sample was centrifuged at 2500 g-force for 10 minutes. A 10 ml aliquot was collected from each sample and was further centrifuged at 2500 g-force for 10 minutes. 1.5 ml aliquot was collected and stored at −20 °C. A high resolution inductively-coupled plasma mass spectrometry instrument (ELEMENT, ThermoFinnigan MAT, Bremen/Germany) was then used for the analysis of metal ions.
The combination of a ceramic head articulating against a metal acetabular liner (CoM) has shown reduced metal ion levels compared with a metal-on-metal bearing (MoM) in hip simulator studies. A randomized prospective clinical trial was undertaken using CoM and MoM bearings in an otherwise identical total hip procedure. The initial clinical results were encouraging. This report comprises a further review of metal ion data.
Patients received identical components with the exception of the bearing surface material but all were 28mm diameter. All components were supplied by DePuy International Ltd. Patients were assessed pre-operatively, 3m, 12m and > 24m (median 32m). Whole blood samples were collected at regular follow-ups, frozen and analysed in batches using high resolution Inductively Coupled Plasma – Mass Spectrometry (ICP-MS). All recruited patients are included irrespective of outcome. However some patients failed to attend specific follow-ups and some contaminated samples had to be discarded. Statistical significance was analyzed using a non-parametric comparison (Mann-Whitney test). After 3m and 12m implantation there were between 21 and 24 patients available for analysis in both the CoM and MoM cohort and after > 24m point 10 and 9 respectively.
There were four outliers (either Cr or Co > 10ug/l) in both the CoM and MoM groups. In common with previous studies (with the exception of two marginal outliers), these were related to component position. They were implanted with either a cup abduction angle of > 55°, an anteversion angle of > 30° or both. Other studies with the same design of component have reported no significant outliers.
The median Cr and the Co levels are lower with the CoM bearing compared with the MoM at all measurements points following implantation. The median background (pre-operative) levels for the combined CoM and MoM group were Cr: 0.22ug/l and Co: 0.49ug/l. These were significantly different (p=0.006).
In the CoM group, the median 12m Cr and Co values were 0.43ug/l and 0.72ug/l respectively. The comparable values for MoM are 0.68ug/l and 0.83ug/l. Increases in metal ion levels from pre-operative levels are used as the primary ion level outcome in this study because the background level will comprise of the order of 30–50% of the overall value. The increase in Cr for CoM and MoM from pre-op levels to 12m significantly different for Cr (p=0.015). It has a lower significance for combined metal ion levels (p=0.029). This difference in not significant for Co (p=0.195).
In agreement with predictions from hip simulator studies, CoM bearings in this study produced lower levels of metal ions than comparable MoM bearings at all time points. However the difference is less than that predicted in the laboratory and is much more pronounced with Cr than with Co.
The acetabular component is a monobloc hemispherical cup manufactured from Ultra High Molecular Weight Polyethylene (UHMWPE), with a pure titanium particle coated surface. With heat and pressure, the particles are blasted into the polyethylene surface. The coating promote osseointegration. Stability of the cup is provided by 2 anchoring pegs on the weight bearing part on its outer surface. The inclination of pegs and holes diverge by 5 degrees providing a press-fit effect that increases the rigidity of the primary fixation and this is supplemented by screws inserted through the periphery of the cup. Tow cups designs are available, a full-profile and a bevelled cup. In all cases the bevelled cup was used. The purpose of this study was to assess the clinical performance with 15 years of this cup.
The diagnosis was osteoarthritis, rheumatic arthritis, femur neck fracture, developmental dysplasia of the hip (DDH). 1034 patients were contacted by telephone. Out of this patients group 539 patients (678 cups) were evaluated by clinical examination (HHS), radiographic investigation and social evaluation by the WOMAC and NHS score. 451 patients who had died unrelated to the operation. Lost of follow up were 65 patients (69 Cups) and 34 patients (48 cups) had to be revised.
Highly cross-linked polyethylene liners in total hip replacement (THR) have allowed the use of larger diameter femoral heads. Larger heads allow for increased range of motion, decreased implant impingement, and protection against dislocation. The purpose of this study is to report the clinical and radiographic outcomes of patients with large femoral heads with HXLPE at 5 years post-op.
A group of 124 patients (132 THRs) who had a primary THR with a 36mm or larger cobalt-chrome femoral head and a Durasul or Longevity liner (Zimmer; Warsaw, IN) were prospectively enrolled in this study. 93 THRs (88 patients) had minimum 5 year follow-up. All patients received a cementless acetabular shell (Trilogy or Inter-op, Zimmer Inc, Warsaw IN) and a highly cross-linked polyethylene liner with an inner diameter of 36 or 38mm. The median radiographic follow-up was 5.6 years (range 5.0–8.0), and patients were assessed clinically by Harris Hip score, UCLA activity score, EQ-5D, and SF-36 functional scores. Femoral head penetration was measured using the Martell Hip Analysis Suite.
No osteolysis was seen in the pelvis or proximal femur, and no components failed due to aseptic loosening. Four patients have questionable signs of bone changes around the acetabular shell with future CT scans scheduled to help reach a final determination. The median acetabular shell abduction and anteversion were 44° (30–66°) and 13° (3–33°) respectively. There was no evidence of cup migration, screw breakage, or eccentric wear on the liner. Regarding the femoral component, there were no episodes of loosening, migration, osteolysis, or fracture. There was no significant difference in the median penetration rate from post-op to longest follow-up between the 36mm (24 patients) and 38mm (4 patients) femoral head groups (0.056±0.10mm/yr and 0.060±0.05mm/yr respectively). Therefore, the data were pooled into one group. Using every post-op to follow-up comparison, the linear regression penetration rate of this combined group was 0.003 mm/yr which is within the error detection of the Martell method. The median femoral head penetration rate during the first post-op year measured 0.59±1.04 mm/yr. In contrast, the median steady state wear rate from the 1yr film to the longest follow-up measured -0.009±0.15mm/yr. A linear regression steady state wear rate from the 1 year film to every follow-up of −0.031 mm/yr indicated no correlation between the magnitude of polyethylene wear and time.
The mid-term results on this series of patients with THRs with a 36 or 38mm femoral head articulating with highly cross-linked polyethylene showed excellent clinical, radiographic, and wear results. The lack of early signs of osteolysis with the use of these large diameter femoral heads is encouraging. Continued and longer-term follow-up is needed to provide survivorship data.
One R3 joint and one BHR device were friction tested in a ProSim hip friction simulator at 0, 3 and 5 million cycles of wear testing. The test was conducted in new born calf serum with added carboxy methyl cellulose (CMC) to generate viscosities of 1 to 100 cP. The loading cycle was set at maximum loads of 2 kN and minimum load of 0.1 kN. The flexion/extension was 30° and 15°, and the frequency was 1 Hz.
Friction: The coefficient of friction (COF) of the R3 joint varied from 0.08 to 0.14 depending on the viscosity of the serum and cycles of wear simulation test. Under physiologically relevant lubricant conditions (1, 3 and 10 cP), the COF for the R3 device tested was comparable to that of the standard BHR device. Wear: The R3 devices generated typical characteristics of wear to the BHR devices, with a higher wear rate during the initial running in period (0 – 0.5 Mc) followed by a low steady state wear rate after 0.5 Mc. The average wear rate at 0.5 Mc was 1.86 mm3/Mc for the R3 and 1.80 mm3/Mc for the BHR devices. The wear rate during the steady state for the R3 and the BHR devices was reduced to 0.09 mm3/Mc and 0.12 mm3/Mc respectively. The difference in average wear rates between the BHR and R3 devices during the running in and steady states were not statistically significant (p >
0.05).
The management of osteoarthritis of the hip in young active patients has always been challenging. This can be made more difficult because of the longevity required of the prostheses used and the level of activity they must endure.
The aim of this study was to compare the functional outcomes and activity levels following hip resurfacing and uncemented THA in young active patients matched for age, gender and activity levels.
A retrospective review of 255 consecutive hip arthroplasties performed in a teaching hospital was carried out. From this series we identified 58 patients who had undergone uncemented THA (Group A) and 58 patients who underwent hip resurfacing (Group B), matched for age, gender and pre-operative activity level.
The mean age of patients within Group A was 58.5 years (34–65) and in Group B was 57.9 years (43–68). Mean pre-operative University of California at Los Angeles (UCLA) score in Group A was 3.4 (1–7) and in Group B was 4.2 (1–8). The mean pre-operative Oxford Hip Score (OHS) was 46.1 (16–60) and 44.4 (31–57) in Groups A and B respectively.
Mean follow-up period was five years (4–7 years). In the hip resurfacing group, the mean UCLA score improved from 4.2 (1–8) to 6.7 (3–10), while in the uncemented THA group this improved from 3.4 (1–7) to 5.8 (3–10). Similarly, the mean OHS improved from 44.4 (31–57) to 16.6 (12–31) in the hip resurfacing group and from 46.1 (16–60) to 18.8 (12–45) in the uncemented THA group.
This study found no statistically significant difference in the levels of function (p= 0.82) or activity pursued (p= 0.60) after surgery between uncemented THA and hip resurfacing in a population of patients matched for age, gender and pre-operative activity levels.
Although there was statistically significant improvement in UCLA and OHS within each group, it was found that no group was better than the other.
This study has shown comparable outcomes with hip resurfacing and uncemented THA in terms of both functional outcomes and activity levels in a group of young active patients. The potential complications unique to hip resurfacing may be avoided by the use of uncemented THA. In addition, uncemented THA has a longer track record.
concomitant hip arthroscopy during osteotomy could identify intra-articular pathology associated with hip dysplasia; hip arthroscopy combined with our technique of acetabular osteotomy was effective in treatment of intraarticular pathology; this technique was associated with a favorable outcome over a mid term followup period.
Radiographic evaluation of the anterolateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. Alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion.
The aim of our study was to analyse the reliability of frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement.
Thirty two patients who presented with femoroac-etabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans.
A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems.
Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate prediction of alpha angle.
We compared patients’ characteristics and outcome following THA in private and public hos-pitals.
To detect eventual difference in patient characteristics- age, gender, diagnosis leading to THA, Carlson’s comorbidity score and Charnley category were evaluated.
We matched 3 658 cases operated in private with 3 658 controllers operated in public hospitals on propensity score. Scoring parameters were age, gender, diagnosis leading to THA, Carlson’s comorbidity score, Charnley category, operating time, type of anesthesia and type of prosthesis.
We used multivariate logistic regression on propensity score matched data to assess association between type of hospital and outcome by computing relative risks and 95% Confidence Interval (CI). Outcomes were perioperative complications, readmission within 3 months, re-operation within 2 years, implant failure after 5 years, and mortality within 3 months of surgery.
Patients in private and propensity matched controls from public hospitals showed no differences in age, gender, diagnosis leading to THA, Carlson’s comorbidity score, Charnley category, operating time, type of anesthesia and type of prosthesis (p-value < 0,0001).
Based on matched data, private hospitals had lower relative risk for perioperative complications (0.39, 0.26–0.60), reoperations (0.59, 0.41–0.83) and readmissions (0.57, 0.42–0.77) compared with public. There was no difference in mortality or implant failure.
We found significant difference between patient characteristics operated at public versus private hospitals. No difference was evident regarding mortality and implant failure but for complications, reoperations and readmissions between private and public hospitals.
The aim of our study was to determine the usefulness of preoperative digital templating of cementless total hip arthroplasty (THA).
60 consecutive cementless THA (synergy stem & reflection cup) were templated digitally by two senior hip arthroplasty fellows (GM, YG) independently. A metallic marker ball of known diameter was used in all images to help scale for magnification. A blinded observer then collated information on the actual implant sizes, size of head component, offset, and level of neck cut intraoperatively. This was used to statistically analyse the correlation (Interclass correlation coefficient) between the digitally templated implant sizes and actual implant sizes used and the reliability of digital templating.
A high rate of coincidence between digitally templated estimates and actual implant sizes was noted for both groups of templates. A high intraclass correlation coefficient (ICC) for the acetabular cup, stem and head were noted (ICC of 0.825, 0.794, and 0.884 respectively). Moderate agreement was noted for neck cut (ICC of 0.567) and leg length (ICC of 0.612).
In conclusion, digital templating can reliably estimate implant sizes in cementless total hip arthroplasty. Valuable information on neck cut and leg length can be obtained by preoperative templating.
Recently, a series of locally destructive soft tissue pseudotumour has been reported in patients following metal-on-metal hip resurfacing arthroplasty (MoMHRA), requiring revision surgery in a high percentage of patients. Based on the histological evidence of lymphocytic infiltration, a delayed hypersensitivity reaction to nickel (Ni), chromium (Cr) or cobalt (Co) has been suggested to play a role in its aetiology. The aim of this study was to investigate the incidence and level of hypersensitivity reaction to metals in patients with pseudotumour.
Group 1: MoMHRA patients with pseudotumours, detected on the ultrasound and confirmed with MRI (n=6, 5 F:1 M, mean age 53 years); Group 2: MoMHRA patients without pseudotumours (n=13, 7 F:6 M, mean age 55 years); and Group 3: age-matched control subjects without metal implants (n=6, 4 F:2 M, mean age 54 years).
Lymphocyte transformation tests (LTT) were used to measure lymphocyte proliferation responses to metals. Peripheral blood mononuclear cells were isolated from heparinized blood samples using standard Ficoll–Hypaque® (Pharmacia). The PBMC were cultured at a cell density of 106 cells/mL. Culture was set up in the presence of either:
medium alone; nickel chloride (Sigma; 10-4M-10-6M); cobalt chloride (10-4M-10-6M); and chromium chloride (10-4M-10-6M).
After 5 days of culture, cells were pulsed with [3H]-thymidine and proliferation was assessed by scintillation counting. The stimulation index (SI) was calculated by the ratio of mean counts per minute of stimulated to unstimulated cultures. A SI value of greater than 2.0 was interpreted as a positive result.
Tribological studies of hip arthroplasty suggest that larger diameter metal-on-metal (MOM) articulations would produce less wear than smaller diameter articulations. Other advantages using these large femoral heads implants include better stability with lower dislocation rates and improved range of motion. The aim of the present study was to compare chromium (Cr), cobalt (Co) and titanium (Ti) ion concentrations up to 1-year after implantation of different large diameter MOM total hip arthroplasty (THA).
Statistical group comparison revealed significant difference for Cr (p=0.006), Co (p=0.047) and Ti (p=< 0.001). With Biomet implants presenting the best results for Cr and Co and Zimmer the highest Ti level.
All the measurements were done by two independent observers and averaged. From the standard radiographs, the sacral slope (SS), the acetabular frontal inclination (AFI), and the acetabular sagittal inclination (ASI) were measured in standing, sitting, and lying positions.
From the CT scan sections, the anatomical ante-version (AA) was measured in lying position on axial images according to Murray. The results were compared to a previously described protocol replicating standing and sitting positions: CTscan sections were oriented according to sacral slope.
An increasing demand for less traumatic THA combined with a faster recovery time has led to minimal invasive surgical approaches and to bone and soft tissue preserving short stem prostheses. Short stem prosthesis should have metaphyseal fixation, primary stability and lesser changes in femoral elasticity which would lead to less stress shielding. The need for a good joint stability and a higher mobility after THA has led to navigated hip surgery together with the use of modular necks to restore the biomechanics.
From November 2004 to July 2008 we implanted 154 Metha prostheses by a modified less invasive Watson-Jones approach. 104 THA were navigated. The indication was primary (32%) or dysplastic coxarthritis (50%) or femoral head necrosis (18%) without affection of the femoral neck, patients age under 50 years and above with good bone density.
Evaluation was done with regard to primary stability, ease of minimal invasive implantation and restoration of the biomechanics. The cup position was aimed at 45° of inclination and 15° of anteversion. The most used modular neck adapter in the non navigated group was standard (135°CCD, 0° antetorsion). In the navigated group more often different variations of neck adapters were used (mainly 135°CCD, 7.5° retrotorsion). Reliable length (+7mm overall) and offset (−3.5mm) measurements could be achieved in the navigated group. The average antetorsion of the stem was 20°.
Bone loss is low with short stem and it is suitable for minimal invasive procedures. A good primary stability seems to be achievable. Modularity leads to a better restoration of the hip biomechanics. In the navigation of the short stem prosthesis the placement of the stem is separated from the restoration of the biomechanics of the hip. The criteria offset, leg length antetorsion, and center of rotation of the head and implant range of motion can be controlled for restoration by navigation. No dislocation was seen in the intraoperative test and in the postoperative follow up.
The short term results show good functional result and a low complication rate without any dislocation. The use of a lesser invasive approach without detaching muscle led to a subjectively faster recovery. The navigation system helps to be precise in cup positioning and to restore biomechanics in term of center of rotation, leg length and offset by advising the best fitting modular neck and reliably predicting the safe range of motion. In our experience the navigated short stem prosthesis offered a good intraoperative handling and good preliminary results.
The use of metal on polyethylene articulations was a key development in establishing total hip arthroplasty as a successful and reproducible treatment for end stage osteoarthritis. In order to ensure implant durability in relatively younger populations, there is a need for alternative, wear resistant bearing surfaces. Oxidized Zirconium (Oxinium, Smith & Nephew, Inc., Memphis, TN) is a relatively new material that features an oxidized ceramic surface chemically bonded to a tough metallic substrate. This material has demonstrated the reduced polyethylene wear characteristics of a ceramic, without the increased risk of implant fracture. The purpose of the current investigation was to assess early clinical outcomes following primary total hip arthroplasty with Oxinium versus Cobalt Chrome femoral heads.
One-hundred primary THA procedures were prospectively performed in 100 patients. There were 52 males and 48 females. Using a process of sealed envelope randomization, patients were divided into 2 groups. Group 1 consisted of fifty patients, each receiving primary THA implants with an Oxinium femoral head (OX). The mean age of each patient was 51 years (SD 10.8, Range 22–74) with 26 males and 24 females. Group 2 also consisted of 50 patients. Within this group again each patient received primary THA implants however with a cobalt-chrome femoral head (CC). Demographics were similar with mean age 51 years (SD 11.0, Range 19–76) and again 26 males and 24 females.
The current study reports clinical outcome measures for both the OX and CC groups at a minimum follow-up of 2 years postoperatively. At the time of latest follow-up, stem survival for both groups was 98%. There was a significant improvement in all clinical outcome scores between preoperative and 2 year postoperative time periods for both bearing groups (p< 0.003). There were no significant differences between bearing groups for any of the clinical outcome scores at final follow-up (p> 0.159). Mean Harris Hip Scores at 2 years postoperatively were 92 and 92.5 for OX and CC, respectively (range; 65–100 OX, 60–100 CC). For SF-12, both the Physical Component Summary Scale (PCS) and the Mental Component Summary Scale (MCS) are reported. Mean PCS scores at final follow-up were 45.2 and 49.21 for OX and CC (range; 27.1–56.7 OX, 26.3–61.8 CC). Mean MCS scores were 53.8 and 52.57 for OX and CC (range; 39.2–65.5 OX, 34.3–64 CC). Mean final WOMAC scores are reported as 84.9 and 87 for OX and CC, respectively.
The current data suggest that total hip arthroplasty utilizing Oxinium femoral heads is safe and effective. Additional follow-up of the current cohort will be performed in order to fully assess mid- to long-term clinical outcomes.
Treatment of recurrent total hip arthroplasty (THA) dislocation is always a surgical challenge. Numerous treatments have been developed, but until now there is no gold standard. The goal of our study was to evaluate the results of a non-constrained tripolar implant (Novae) in this indication.
Radiological examination was performed numerically with the software Imagika®
Pore size was between 800 and 1500 microns with an overall porosity of 60%. The pore depth of the interconnecting surface structure reached up to 3000 microns.
The purpose of this retrospective study is to report the long term results of Spongiosa Metal I cement less total hip prosthesis in Japan.
The all evaluated prosthesis combined 28mm ceramic head and polyethylene inlay.
2 cups and 1 stem were revised by aseptic loosening.
2 stem breakage and 7 ceramic head fracture were seen while following up.
85% of the patients had retained the original prostheses (cup, stem, ceramic head, and inlay).
Survival rate was investigated by Kaplan-Meier method.
Survival rate for the cup component was 95%, and for the stem component was 93%.
We thought that beating with the hammer when we install the ceramic head to the taper was one problem.
On the other hand, few aseptic loosening was seen while following up.
These results suggest that spongiosa metal system can bear for long term of use.
Main reason for the revision surgery is ceramic head fracture.
We are convinced with this spongiosa metal surface can bear long term of use.
Navigation technology is a new tool which can help surgeons to a more accurate hip component implantation and a better reproducibility of the procedure.
The purpose of this study was to compare conventional and navigated technique and a new developed straight hip stem for uncemented primary total hip replacement.
The results of two consecutive implantation series of 42 patients (non navigated) and 42 patients (navigated) were analysed for implant positioning and short term complications. Non navigated components were implanted through conventional incision (15 cm), navigated component by minimal invasive surgery (5 cm). All surgeries were performed through Hardinge approach and by a single senior surgeon.
Radiographic analysis of cup position showed a significant improvement with reduced radiological inclination (53° non navigated/44° navigated, p< 0.001) and higher anteversion (7° non navigated/12° navigated, p< 0.001). The mean postoperative limb length difference was 6.2 mm (SD 9.0, non navigated) and 4.4 mm (SD 6.4, navigated). Intraoperative and early postoperative complications were not different. No dislocation occurred in both groups. There was one intraoperative trochanter fracture which was not revised (non navigated) and one revision because of a periprosthetic fracture caused by fall down during rehabilitation (navigated).
We conclude that acetabular implant positioning can be significantly improved by the use of navigated surgery technique even in minimal invasive surgery condition. The data for postoperative limb length difference was still similar but within the expected range in both groups. Navigation technology seems essential for minimal invasive surgical procedure yielding help and security to the surgeon. The effect of improved cup positioning on mid and long term results for both groups have to be further investigated.
None of the patients required cup revision for aseptic loosening. Complications included 12 dislocations and 3 deep infections resulting in 2 total revisions. In 3 patients the stem was revised for aseptic loosening at a mean of 63 months. At 10-years the survivorship was 98.6% (95% CI 96.7; 99.4) with endpoint revision for any cause.
Mean total wear was 0.89 mm (±0.5). 32 cups (18.8%) with a cup inclination > 45° had a mean wear of 1.06 mm (±0.5), whereas 138 cups (81.2%) with inclination < 45° had a mean wear of 0.86 mm (±0.5), p=0.036. In 16 cases osteolytic defects around the stem were present. The outcome scores at 10 years were: HHS 85.9 (±14.1), WOMAC pain 70.7 (±24.7), WOMAC function 68.8 (±24.5), SF-12 physical score 40.3 (±9.2) and mental score 47.0 (±10.4). Ninety-four percent of the patients were satisfied or very satisfied.
The proximally hydroxyapatite coated neck retaining Freeman hip stem (Finsbury Orthopaedics, Leather-head, United Kingdom.) was first implanted in 1989. The outcome of the first 100 stems, in 52 men (6 bilateral) and 40 women (2 bilateral) has been reported to ten years, we have extended the follow-up of this series to 17 years.
The mean age was 58.9 years (19 to 84). The diagnosis was osteoarthritis for 70 hips, rheumatoid arthritis for seven hips, post-traumatic arthritis for 14 hips and either avascular necrosis, septic arthritis or developmental hip disorder in nine hips.
The total hip replacements implanted during the period of study (January 1989 to March 1992) were all secured without cement for either component. The acetabular components comprised press-fitted screw-in Rotalok implants (Corin Medical, Cirencester, United Kingdom) or SLF components (Finsbury). All operations were performed using an anterolateral approach with retention of the femoral neck. Three patients have been lost to follow-up, but are included up to their last clinical follow-up.
There have been 40 re-operations for revision of the acetabular component due to aseptic loosening. However, in all but four of these cases the stem was not revised. In two of these the stem revisions were for damage to the trunion following fracture of the modular ceramic head producing fretting against the ceramic debris and acetabular component. In the other two, revision was due to surgeon preference and in both cases well fixed femoral components were extracted at the time of acetabular revision. Osteointegration of these two stems was evidenced by the adherent bone at the time of removal. There has been only one case of aseptic loosening occurring at 14 years. This was found to be rotationally loose at revision and in hindsight was undersized having migrated distally 7.6mm in the first year before stabilising. The survivorship for the stem at 17 years is 98.5% (95% CI; 94.6% to 100%) with 52 patients at risk, all of whom have satisfactory clinical and radiological outcomes. The Freeman uncemented neck retaining proximally hydroxyapatite coated stem has excellent survival results to 17 years.
During the last decade, outcome assessment in orthopaedic surgery has increasingly focused on patient self-report questionnaires. The Oxford Hip and Knee Scores (OHS and OKS) were developed for the self-assessment of pain and function in patients undergoing joint replacement surgery. These scores proved to be reliable, valid, and responsive to clinical change, however, no German version of these useful measures exists. We therefore cross-culturally adapted the OHS and OKS according to the recommended forward/backward translation protocol and assessed the following metric properties of the questionnaires in 105 (OHS) and 100 (OKS) consecutive patients undergoing total hip or knee replacement in our clinic: feasibility (percentage of fully completed questionnaires), reliability (intraclass correlation coefficients (ICC) and Bland and Altman’s limits of agreement), construct validity (correlation with the Western Ontario and McMaster Universities Index (WOMAC), Harris Hip Score (HHS), Knee Society Score (KSS), Activities of Daily Living Scale (ADLS), and Short Form (SF-)12), floor and ceiling effects, and internal consistency (Cronbach’s alpha, CA). We received 96.6% (OHS) and 91.9% (OKS) fully completed questionnaires. Reliability of both questionnaires was excellent (ICC > 0.90). Bland and Altman’s limits of agreement revealed no significant bias. Correlation coefficients with the other questionnaires ranged from −0.30 (SF-12 Mental Component Scale) to 0.82 (WOMAC) for the OHS, and from −0.22 (SF-12 Mental Component Scale) to −0.77 (ADLS) for the OKS. For both questionnaires, we observed no floor or ceiling effects. The internal consistency was good with a CA of 0.87 for the OHS and 0.83 for the OKS. In conclusion, the German versions of the OHS and OKS are reliable and valid questionnaires for the self-assessment of pain and function in German-speaking patients with hip or knee osteoarthritis. Considering the present results and the brevity of the measures, we recommend their use in the clinical routine.
The goal of this study was to develop and validate a short, evaluative self-report questionnaire for the clinical self-assessment of patients with hip osteoarthritis (OA). If used together with other self-report outcome tools (e.g. generic or physical activity measures), such a short joint-specific questionnaire could avoid an increased burden to the patients and decrease the risk of data loss. All items of the new score (Schulthess Hip Score, SHS) were generated solely on patient perceptions, for item removal we used the clinical severity-importance rating and inter-item correlation methods. The final score consisted of only five items. We then assessed the following metric properties of the SHS in 105 consecutive patients with symptomatic hip OA (mean age, 63.4 ± 11 years, 48 women) undergoing total hip arthroplasty (THA) in our clinic: proportion of evaluable questionnaires, reproducibility, internal consistency, concurrent validity, and responsiveness. 97% of the questionnaires were evaluable. Reproducibility of the SHS was excellent (intraclass correlation coefficient (ICC) 0.90; standard error of the measure (SEM) 6.4). Exploratory factor analysis indicated that all items loaded on only 1 factor which accounted for 69.4% of the total variance. Cronbach’s alpha was 0.88. Evidence of convergent validity was provided by moderate to high correlations with scores and subscales of the WOMAC (r = 0.58–0.78), Oxford Hip Score (r = 0.78), Harris Hip Score (r = 0.37), SF-12 physical component scale (r = 0.57), UCLA activity scale (r = 0.48), and Tegner score (r = 0.53). Evidence of divergent validity was provided by a lower correlation with the SF-12 mental component scale (r = 0.37). The SHS proved to be responsive with an effect size (ES) of 2.15 and a standard response mean (SRM) of 1.74 six months after THA. Taken together, the results of this study provide evidence to support the use of the five-item self-report SHS in patients with hip osteoarthritis. Considering the brevity of this score, it could be easily used together with other measures such as generic and physical activity assessment tools, without overburdening patients with an inordinate number of items and questions.
an abnormal alpha angle (>
49°) measured on the elongated femoral neck x-ray, a positive cross-over sign or pro-trusio acetabuli in the AP pelvis x-ray, the presence of diminished anteversion in the femur (<
10°) or a retroverted femur (<
0°) in the CT scan, associated with a positive hip impingement test and lack of internal rotation at 90 degrees of flexion.
We documented the type of FAI, the presence of acetabular dysplasia, coxa valga, coxa vara and the femoral version measured on the CT scan. The degree of osteoarthritis of the hip using the Tönnis classification was documented as well.