Introduction

Hips following in-situ pinning for slipped capital femoral epiphysis (SCFE) have an altered morphology of the proximal femur with cam type deformity. This deformity can result in femoroacetabular impingement and early joint degeneration. The modified Dunn procedure allows to reorientate the slipped epiphysis to restore hip morphology and function.

Introduction. A key outcome measured by national joint registries are revision events. This informs best practice and identifies poor-performing surgical devices. Although registry data often record reasons for revision arthroplasty, interpretation is limited by lack of standardised definitions of revision reasons and objective assessment of radiologic and laboratory parameters. Our study aim was to compare reasons for unicompartmental knee arthroplasty (UKA) revision reported to the New Zealand Joint Registry (NZJR) with reasons identified by independent clinical review. Methods. A total of 2,272 patients undergoing primary medial and lateral UKA at four large tertiary hospitals between 2000 and 2017 were included. A total of 158 patients underwent subsequent revision with mean follow-up of 8 years. A systematic review of clinical findings, radiographs and operative data was performed to identify revision cases and to determine the reasons for revision using a standardised protocol. These were compared to reasons reported to the NZJR using Chi-squared and Fisher exact tests. Results. Osteoarthritis progression was the most common reason for revision on systematic clinical review (30%), however this was underreported to the registry (4%, p<0.001). A larger proportion of revisions reported to the registry were for ‘unexplained pain’ (30% of cases vs. 4% on clinical review, p<0.001). A reason for revision was not reported to the registry for 24 (15%) of cases. Discussion and Conclusion. We found significant inaccuracies in registry-reported reasons for revision following UKA. These included over-reporting of ‘unexplained pain’, under-reporting of osteoarthritis progression, and failure to identify a reason for revision. Efforts to improve registry capture of revision reasons for UKA should focus on increasing accuracy in these three areas. This could be addressed through standardised recording methods and tailored revision reason options for UKA for surgeons to select when recording the reasons

Source of the study: University of Auckland, Auckland, New Zealand. Unicompartmental knee arthroplasty (UKA) is effective for patients with isolated compartment osteoarthritis, however the procedure has higher revision rates. Long-term survivorship and accurate characterisation of revision reasons are limited by a lack of long-term data and standardised revision definitions. We aimed to identify survivorship, risk factors and revision reasons in a large UKA cohort with up to 20 years follow-up. Patient, implant and revision details were recorded through clinical and radiological review for 2,137 consecutive patients undergoing primary medial UKA across Auckland, Canterbury, Counties Manukau and Waitematā DHB between 2000 and 2017. Revision reasons were determined from review of clinical, laboratory, and radiological records for each patient using a standardised protocol. To ensure complete follow-up data was cross-referenced with the New Zealand Joint Registry to identify patients undergoing subsequent revision outside the hospitals. Implant survival, revision risk and revision reasons were analysed using Cox proportional-hazards and competing risk analyses. Implant survivorship at 15 years was comparable for cemented fixed-bearing (cemFB; 91%) and uncemented mobile-bearing (uncemMB; 91%), but lower for cemented mobile-bearing (cemMB; 80%) implants. There was higher incidence of aseptic loosening with cemented implants (3–4% vs. 0.4% uncemented, p<0.01), osteoarthritis (OA) progression with cemMB implants (9% vs. 3% cemFB/uncemMB; p<0.05) and bearing dislocations with uncemMB implants (3% vs. 2% cemMB, p=0.02). Compared with the oldest patients (≥75 years), there was a nearly two-fold increase in risk for those aged 55–64 (hazard ratio 1.9; confidence interval 1.1-3.3, p=0.03). No association was found with gender, BMI or ASA. Cemented mobile-bearing implants and younger age were linked to lower implant survivorship. These were associated with disease progression and bearing dislocations. The use of cemented fixed-bearing and uncemented mobile-bearing designs have superior comparable long-term survivorship

Introduction & Objective. Labral refixation has established as a standard in open or arthroscopic treatment for femoroacetabular impingement (FAI). The rationale for this refixation is to maintain the important suction seal in the hip. To date, only few short-term results are available which indicate a superior result in FAI hips with labral refixation compared to labral resection. Scientific evidence of a beneficial effect of labral refixation in the long-term follow-up is lacking. Aim of this study was to evaluate if labral refixation can improve the cumulative 10-year survivorship in hips undergoing surgical hip dislocation for FAI compared to labral resection. Methods. We performed a retrospective comparative study of 59 patients treated with surgical hip dislocation for symptomatic FAI between December 1998 and January 2003. We analyzed two matched groups: The ‘resection’ group consisted of 25 hips that were treated consistently by excision of the damaged labrum. The ‘refixation’ group consisted of 34 hips that were treated with labral reattachment. Correction of the osseous deformity (rim trimming/femoral osteochondroplasty) did not differ between the two groups. We then evaluated the clinical (Merle d'Aubigné score) and radiographical results (according to Tönnis) at a follow-up of ten years. We calculated a cumulative Kaplan-Meier survivorship curve with the following factors as endpoints: conversion to total hip arthroplasty (THA), radiographic evidence of osteoarthritis progression, or a poor clinical result (defined as Merle d'Aubigné score of less than 15). The two curves were compared using the Log-rank test. Results. Hips with labral refixation had a significantly higher survivorship (78%, 95% confidence interval [CI] 64–92%) at ten years compared to labral resection (46%, 95% CI 26–66, p=0.008). 7 (20.6%) patients in the refixation group reached an endpoint: 2 with THA; 5 with a poor clinical result, and 5 with progression of OA. 15 (60.0%) patients in the resection group reached an endpoint: 3 with THA; 12 with a poor clinical result, and 4 with progression of OA. Conclusion. This is the first study proving that labral refixation leads to significantly better results in patients 10 years after open surgical hip dislocation for FAI. It seems advisable to preserve the labrum in this patient population whenever possible

The suggestion of a meniscal tear produces a pavlovian response in the orthopaedic surgeon. However, meniscal signal anomalies and associated changes become common with age in symptom free knees. T he issue for the IME requested to assess workers with painful knees is to determine if the MRI changes represent a painful injury and if the treatment planned (usually arthroscopy) may, in fact, be harmful. MRI signal changes are assessed on the likelihood they predict for unstable meniscal tears. Some patterns of meniscal tears are benign. Associated changes such as baker's cyst and ligament thickening are also common but are poor predictors of symptomatic tears. Preclinical osteoarthritis has a high incidence of associated meniscal change and arthroscopic menisectomy may accelerate osteoarthritis progression. Clinical tests have variable specificity and sensitivity but in combination with an understanding of the patterns of MRI signal can be combined to predict which meniscal tears would benefit from arthroscopic surgery, which injuries would do as well with non-operative treatment and which patterns predict deterioration after surgery. As the views of the IME are often contrary to the surgeon, a comprehensive bibliography is provided for any who need to argue their case. As the topic is information and image dense, a CD ROM will be distributed

INTRODUCTION. The literature suggests a survivorship of unicompartmental knee arthroplasties (UKA) for spontaneous osteonecrosisof the knee range from 93% to 96.7% at 10 to 12 years. However, these data arise from series reporting 23 to 33 patients, jeopardizing meaningful conclusions. OBJECTIVES. Our purpose is to examine a long term survivorship of UKA's in a larger group of patients with SPONK, along with their subjective, symptomatic and functional outcome; to determine the percentage of failures and the reasons for the same in an attempt to identify relevant indications, contraindications, and technical parameters in treating SPONK with a modern implant design. METHODS. We retrospectively evaluated 84 patients with late-stage spontaneous osteonecrosis of the knee who had a medial UKA from 1998 to 2005. All patients had preoperative MRI to confirm the diagnosis, exclude metaphyseal involvemente, and confirm the absence of major degenerative changes in the lateral and patellofermoal compartment. Mean age at surgery was 66 years and mean body mass index was 28.9. A Kaplan-Meier survival analysis was conducted using revision for any reason as the end point. The minimum followup of 63 months (mean, 98 months; range, 63–145 months). RESULTS. The 10-year survivorship was 92%. Ten revisons were performed and the most common reasons for revision were subsidence of the tibial component (four) and aseptic loosening of the tibial component (three). No patient underwent revision for osteoarthritis progression in the lateral or patellofemoral compartment. There was a statistically significant difference between postoperative VAS, KSS, WOMAC, Oxford, Range of Motion and Tibial Slope (overcorrected by 3.7 degrees, p< 0.0023) between the survivors and the failures. CONCLUSION. SPONK may be an optimal indication for UKA provided secondary osteonecrosis of the knee is ruled out; pre-operative MRI is performed to document involvement of other compartments, status of the ligaments and depth of lesion; and there is no over-correction in any plane