Mid-term results of ReCap/Magnum/Taperloc metal-on-metal total hip arthroplasty with mean follow-up of 7.1 years

Introduction: Despite enthusiasm for metal-on-metal bearings, disappointing short-to mid-term outcomes has all but halted the use of this bearing articulation. This review presents mid-term results for the ReCap Magnum total hip replacement. Patients and methods: This prospective study evaluated 79 ReCap/Magnum/Taperloc total hip replacements with mean follow-up of 7.1 (range 3.7-9.2) years. 43 were female and 36 male. Metal ions were measured and radiographic measurement included a 'margin of safety' angle to quantify risk of edge loading. When a clinical suspicion of adverse reaction to metal debris was present, patients had metal artefact reduction sequence MRI. Harris Hip Score and Oxford Hip Score evaluated functional outcome and SF-12 and EQ-5L-5D assessed quality of life at final follow-up. Results: 7 hips were revised indicating 91.1% survivorship at 7.1 years. Postoperative Harris Hip Score and Oxford Hip Score significantly improved. Females and symptomatic patients predicted increased metal ions. Margin of safety correlated with postoperative Oxford Hip Score. Symptomatic hips and positive MRI showed reduced survivorship. Conclusions: Compared to more traditional bearings like metal or ceramic on polyethylene the overall outcome of this ReCap/Magnum/Taperloc study cohort is modest. It is felt that further failures will occur in this group therefore cautious interpretation of the results is justified given the potential for reduced survival outcomes.