Hip resurfacing results for osteonecrosis are as good as for other etiologies at 2 to 12 years.

UNLABELLED: A bone-conserving prosthetic solution, such as hip resurfacing arthroplasty, is desirable for patients with osteonecrosis (ON) of the femoral head because of their young age. However, many surgeons are reluctant to perform hip resurfacing for ON because of large femoral head defects. To ascertain whether this reluctance is warranted, we determined the mid- to long-term effects of ON on the survivorship, radiographic implant fixation, and disease-specific and quality-of-life scores of hip resurfacing. We compared the results of metal-on-metal resurfacing performed for ON of the hip (including large lesions) with those of resurfacing performed for other causes. The ON group had 70 patients (85 hips) and the control group 768 patients (915 hips) including all other etiologies operated on during the same period. The ON group was younger and had a greater incidence of femoral defects, a smaller component size, and a lower body mass index, three variables previously shown to reduce survivorship in hip resurfacing. We observed no difference in survivorship between the ON group and the control group even after adjusting for head size, body mass index, and defect size. Pain relief, walking, and function scores were comparable postoperatively. The activity level was lower in the ON group. Our data suggest ON is not a contraindication for resurfacing even with large femoral head defects. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.