The outcome and survival of metal-on-metal hip resurfacing in patients aged less than 50 years: a prospective observational cohort study with minimum ten-year follow-up.

AIMS: The aim of this study was to report the implant survival and patient-reported outcome measures (PROMs) in a consecutive series of patients aged less than 50 years at the time of arthroplasty using the Birmingham Hip Resurfacing system (BHR), with a minimum follow-up of ten years. PATIENTS AND METHODS: A total of 226 patients with osteoarthritis of the hip, who underwent BHR and presented to a single surgeon, were included in the study. Survival of the implant was confirmed by cross-checking with the Australian Orthopaedic Association National Joint Replacement Registry. Kaplan-Meier survival curves with 95% confidence intervals (CIs) were constructed. Pre- and postoperative PROMs were compared with t-tests, and postoperative scores were compared using anchor analysis with age and gender matched normative data. RESULTS: At median follow-up of 12 years (interquartile range (IQR) 10 to 13), six BHRs were revised, with a cumulative rate of survival of 96.8% (95% confidence interval (CI) 94.2 to 99.4) at 15 years, and with a significantly lower (p = 0.019) cumulative rate of revision than the national average for the same device at ten years. Most revisions (n = 4) were undertaken early, less than three years postoperatively, and occurred in women. Patient-reported general health (Veteran's Rand-36), disease state (Western Ontario and McMaster Universities Osteoarthritis Index), function (modified Harris Hip Score) and level of activity (Tegner activity score) maintained significant (p < 0.01 for each) improvements beyond ten years postoperatively and were equal to, or exceeded, age- and gender-matched normative data in more than 80% of the patients. CONCLUSION: Longer term PROMs after BHR, from a single surgeon, for patients aged less than 50 years remain under-reported. We found that the outcome after a BHR, at a minimum of ten years postoperatively, remained satisfactory, particularly for self-reported hip function.

Patient outcomes using Wii-enhanced rehabilitation after total knee replacement - the TKR-POWER study.

BACKGROUND: Home-based rehabilitation following total knee replacement surgery can be as effective as clinic-based or in-patient rehabilitation. The use of the Nintendo Wii has been postulated as a novel rehabilitation tool that adds an additional focus on balance and proprioception into the recovery protocol. The aim of the proposed clinical trial is to investigate the effectiveness of this novel rehabilitation tool, used at home for three months after total knee replacement surgery and to assess any lasting improvements in functional outcome at one year. METHODS/DESIGN: This will be a randomised controlled trial of 128 patients undergoing primary total knee replacement. The participants will be recruited preoperatively from three surgeons at a single centre. There will be no change to the usual care provided until 6 weeks after the operation. Then participants will be randomised to either the Wii-Fit group or usual rehabilitative care group. Outcomes will be assessed preoperatively, a 6-week post surgery baseline and then at 18 weeks, 6 months and 1 year. The primary outcome is the change in self-reported WOMAC total score from week 6 to 18 weeks. Secondary outcomes include objective measures of strength, function and satisfaction scores. DISCUSSION: The results of this clinical trial will be directly relevant for implementation into clinical practice. If beneficial, this affordable technology could be used by many patients to rehabilitate at home. Not only could it optimize the outcomes from their total knee replacement surgery but decrease the need for clinic-based or outpatient therapy for the majority. TRIAL REGISTRATION: (ACTRN12611000291987).

Can tibial coverage in total knee replacement be reliably evaluated with three-dimensional image-based digital templating?

OBJECTIVES: There remains a lack of data on the reliability of methods to estimate tibial coverage achieved during total knee replacement. In order to address this gap, the intra- and interobserver reliability of a three-dimensional (3D) digital templating method was assessed with one symmetric and one asymmetric prosthesis design. METHODS: A total of 120 template procedures were performed according to specific rotational and over-hang criteria by three observers at time zero and again two weeks later. Total and sub-region coverage were calculated and the reliability of the templating and measurement method was evaluated. RESULTS: Excellent intra- and interobserver reliability was observed for total coverage, when minimal component overhang (intraclass correlation coefficient (ICC) = 0.87) or no component overhang (ICC = 0.92) was permitted, regardless of rotational restrictions. CONCLUSIONS: Measurement of tibial coverage can be reliable using the templating method described even if the rotational axis selected still has a minor influence.

Different changes in slope between the medial and lateral tibial plateau after open-wedge high tibial osteotomy.

PURPOSE: In contrast to radiographic measurements, MRI provides multiple slices of the knee joint in the sagittal plane, making it possible to assess the medial and lateral tibial slope separately. The purpose of this study is to investigate the effect of medial open-wedge high tibial osteotomy (MOWHTO) on bony and meniscal slope in the medial and lateral tibiofemoral compartments. It was hypothesised that greater changes on the medial tibial plateau would be observed compared with the lateral one. METHODS: A retrospective analysis of prospectively collected data was performed on pre- and post-operative MRIs from 21 patients (17 men and 4 women; age 52 ± 9 years). Inclusion criteria were varus alignment, medial compartment osteoarthritis and election for a primary MOWHTO. Each patient had a preoperative and a post-operative high-resolution MRI (3Tesla, Magnetom Trio, Siemens AG) at an average follow-up of 2.1 years. A previously published method was used to measure bony and meniscal slope for each compartment. The difference between pre- and post-operative tibial slope for both compartments was calculated and associated with the amount of frontal correction. RESULTS: There was a significant increase in bony tibial slope in both compartments following MOWHTO. When a change in bony tibial slope was detected in an individual patient, the change was larger in the medial compartment, with the average change also significantly greater (p < 0.01) in the medial compartment (2.4° ± 1.3°) compared with the lateral compartment (0.9° ± 1.1°). There was also a significant increase (p < 0.01) in the lateral tibial meniscal slope of 0.9° ± 1.4°, which was equivalent to the change in the bony lateral slope. The amount of frontal correction was not significantly associated with the amount of change in slope. CONCLUSIONS: The results suggest that the modification of the bony slope is larger in the medial compartment after MOWHTO, which is likely related to the location of the hinge on the lateral tibial cortex. These findings suggest that consideration of the medial and lateral tibial slope intra-operatively could be important to identify the optimal location of the hinge. However, further studies are required before recommending any modification to the surgical technique, as the potential clinical consequences of tibial slope alterations remain unknown. LEVEL OF EVIDENCE: IV.