What is the learning curve associated with a hip resurfacing?

There is a paucity of literature on the minimum number of cases necessary to become an expert surgeon in hip resurfacing arthroplasty (HRA). Thus, we aimed to describe (I) the learning curve of a primary hip replacement; (II) the learning curve of HRA using different end-points (complications, joint survival, component alignment and patient-reported outcome measures); and (III) what the minimum number of cases performed per year should be to maintain competency. A comprehensive literature search was performed reviewing joint arthroplasty registries, case-controlled studies, and case-series that have reported on the above. The reported learning curve necessary to decrease the overall complication rate in primary total hip arthroplasty (THA) is 90 cases. Additionally, the literature suggests that at least 35 primary THA cases per year is the recommended number above which complications reduce significantly. There is no doubt that only surgeons trained in primary hip replacement should perform HRA of the hip. On average, a learning curve of 50 cases has been described. Following this threshold, less complications, better radiographic assessment and superior patient reported outcomes have been described. It is the authors’ opinion that at least 25 cases should be performed annually, which is in line with other highly specialized surgical procedures.