The Müller self-locking cemented total hip prosthesis with polyethylene liner: After twenty years, what did they become?

BACKGROUND: The M.E. Müller (MEM) prosthesis is a self-locking straight stem. Although this prosthesis is widely used, few outcomes have been published thus far. METHODS: We examined long-term outcomes with the MEM cemented self-locking total hip arthroplasty (THA) with a polyethylene liner and 28-mm head. Between 1993 and 1994, 167 patients (173 hips) underwent primary THA implantation and were invited for clinical and radiological review a mean of 20.6 (20.1 - 21.7) years later; 111 patients had a metal and 62 a ceramic head. Hip function was assessed using the Postel Merle d'Aubigné Score. RESULTS: Overall, 121 patients died and six were lost to follow-up. Forty patients (41 hips) were reviewed. Five patients required revision, of whom two were due to acetabular loosening, one to premature haematoma, one to recurrent dislocation and one to femoral fracture. Wear levels were significantly lower with ceramic than metal heads. The majority of radiological or clinical failures were acetabular (7.3 % versus 2.4 % femoral). At the femoral level, osteolysis was observed in seven patients (17 %). Twenty-year survival was 88.67 ± 6.61 % using an endpoint of all-cause revision and 97.9 ± 2.1 % using femoral failure as the endpoint. CONCLUSION: Our retrospective analysis confirms the good results seen with the MEM stem in the literature and support the "French paradox" concept. Failures of these prostheses with a cemented polyethylene cup are largely on the acetabular side and, as such, the cup is the weak link. Improvements in survival will require optimisation of cup fixation and the use of a ceramic head to reduce wear in patients with a long life expectancy.

Determinants of satisfaction 1 year after total hip arthroplasty: the role of expectations fulfilment.

BACKGROUND: Between 7% and 15% of patients are dissatisfied after total hip arthroplasty (THA). To assess predictors and postoperative determinants of satisfaction and expectation fulfilment one year after (THA). METHODS: Before THA surgery, 132 patients from three tertiary care centres and their surgeons were interviewed to assess their expectations using the Hospital for Special Surgery Total Hip Replacement Expectations Survey (THR survey). One year after surgery, patients (n = 123) were contacted by phone to complete a questionnaire on expectation fulfilment (THR survey), satisfaction, functional outcome (Womac), and health-related quality of life (SF 12). Univariate and multivariate analyses were performed. RESULTS: Preoperative predictors of satisfaction were a good mental wellbeing (adjusted OR 1.09 [1.02; 1.16], p = 0.01) and optimistic surgeons expectations (1.07 [1.01; 1.14], p = 0.02). The main postoperative determinant of satisfaction was the fulfilment of patient's expectations (1.08 [1.04; 1.12], p < 0.001). Expectation fulfilment could be predicted before surgery by young age (regression coefficient -0.55 [-0.88; -0.21], p = 0.002), good physical function (-0.96 [-1.82; -0.10], p = 0.03) and good mental wellbeing (0.56 [0.14; 0.99], p = 0.01). Postoperative determinants of expectation fulfilment were functional outcome (-2.10 [-2.79; -1.42], p <0.001) and pain relief (-14.83 [-22.38; -7.29], p < 0.001). CONCLUSION: To improve patient satisfaction after THA, patients' expectations and their fulfilment need to be carefully addressed. Patients with low mental wellbeing or physical function should be identified and specifically informed on expected surgical outcome. Surgeons' expectations are predictive of satisfaction and information should aim to lower discrepancy between surgeons' and patients' expectations.

Comparison of patient and surgeon expectations of total hip arthroplasty.

OBJECTIVES: Analysis of discrepancies between patient and surgeon expectations before total hip arthroplasty (THA) should enable a better understanding of motives of dissatisfaction about surgery, but this question has been seldom studied. Our objectives were to compare surgeons' and patients' expectations before THA, and to study factors which affected surgeon-patient agreement. METHODS: 132 adults (mean age 62.8+/-13.7 years, 52% men) on waiting list for THA in three tertiary care centres and their 16 surgeons were interviewed to assess their expectations using the Hospital for Special Surgery Total Hip Replacement Expectations Survey (range 0-100). Patients' and surgeons' answers were compared, for the total score and for the score of each item. Univariate analyses tested the effect of patients' characteristics on surgeons' and patients' expectations separately, and on surgeon-patient differences. RESULTS: Surgeon and patient expectations' mean scores were high (respectively 90.9+/-11.1 and 90.0+/-11.6 over 100). Surgeons' and patients' expectations showed no systematic difference, but there was little agreement on Bland and Altman graph and correlation coefficient was low. Patients had higher expectations than surgeons for sports. Patients rated their expectations according to trust in physician and mental quality of life, surgeons considered disability. More disabled patients and patients from a low-income professional category were often "more optimistic" than their surgeons. CONCLUSION: Surgeons and patients often do not agree on what to expect from THA. More disabled patients expect better outcomes than their surgeons.