Background: Characteristically, osteonecrosis affects younger patients who typically refer to the orthopedic surgeon for the first time in the third to fifth decades of life, in the late stages of the disease. Femoral metal-on-metal hip resurfacing is as an alternative to conventional total hip arthroplasty in treating osteoarthritis of the hip. Since there are already many reports regarding the successful outcome of resurfacing in advanced osteoarthritis, the purpose of this study was to analyze the clinical outcomes of this procedure in patients with osteonecrosis of the femoral head and to compare them with a matched group of patients with osteoarthritis.
Material/Methods: This retrospective cohort study evaluated a consecutive series of 52 patients with end-stage osteonecrosis (28 patients) and osteoarthritis (24 patients) of the femoral head, managed by metal-on-metal hip resurfacing in a referral orthopedic center from Feb 2002 to May 2007. Pain, function and deformity were evaluated with the use of the Harris hip score after the operation. Patients were clinically followed for a mean of 41 months.
Results: The patients in the osteoarthritis group had a significantly higher mean age than those in the osteonecrosis group (47.88±12.6 vs 30.86±7.5, p=0.003).
The clinical outcomes were similar for both groups. There was no significant difference in mean Harris hip score (p=0.347) and hip joint range of motion (p=0.346) between osteonecrosis and osteoarthritis groups after surgery.
Conclusions: On the basis of these initial findings, we recommend MOM resurfacing as a viable treatment option for patients with advanced stages of osteonecrosis.

Keywords: Osteonecrosis - surgery, Osteoarthritis - surgery, Metals, Hip Prosthesis, Arthroplasty, Replacement, Hip - methods, Time Factors