Comparative study between patients with osteonecrosis and osteoarthritis after hip resurfacing arthroplasty.

The purpose of this study was to compare the clinical outcomes of osteonecrosis (ON) and osteoarthritis (OA) patients after metal-on-metal hip resurfacing arthroplasty (HRA). We retrospectively reviewed our database and identified a study group of 122 HRA cases with the primary diagnosis of ON. A control group of 122 OA cases were randomly selected by a computer program to match the surgical date, gender and the femoral component type and size with the study group. We compared the results between these two groups and also compared the clinical outcome between cemented and uncemented HRA in ON cases. Overall survivorship, using any revision as an endpoint, was 88% for ON, compared to 100% for OA at ten years. There were no femoral failures in 47 uncemented femoral cases. Our study suggests that HRA may not be suitable for everyone, such as ON patients.