Metal-on-metal hip resurfacing compares favorably with THA at 2 years followup.

Metal-on-metal total hip resurfacing is a bone-conserving reconstructive option for patients with advanced articular damage. While intended to address several problems with conventional THA, the safety and efficacy is not well established. We therefore retrospectively compared the outcomes of 52 patients (57 hips) with resurfacing arthroplasty to 84 patients (93 hips) with cementless primary THAs. The patients had a minimum 2-year followup (mean 3 years). The patients with resurfacing arthroplasty had a mean age of 47 years (range, 22-64) while those with cementless primary THA had a mean age of 57 years (range, 17-92). After controlling for age, gender, and preoperative differences, the total Harris Hip Scores (HHS), function scores, and pain scores were similar between the two groups. However, the resurfacing group had higher activity scores (14 versus 13, p < 0.001) and range of motion (ROM) scores (5.0 versus 4.8, p < 0.001). The complication rates (5.3% for resurfacing versus 14.0% for THA) and reoperation rates (3.5% for resurfacing versus 4.3% for THA) were similar. The total hip arthroplasty and metal-on-metal resurfacing groups both showed improvement in HHS, pain, activity, and ROM and had similar early complication and reoperation rates.