Total Hip Arthroplasty in Advanced Osteonecrosis: Short-Term Results by Metal-on-Metal Hip Resurfacing

Avascular necrosis (AVN) of femoral head, with resultant joint destruction, is a common disabling disease of fourth and fifth decades of life. Metal-on-metal resurfacing is a relatively newer treatment modality for this disease. The aim of this study is to compare the result of resurfacing for osteonecrosis with that of resurfacing for other causes. Twenty eight patients with stage III or IV (Ficat & Arlet) osteonecrosis who underwent metal-on- metal hip resurfacing were compared with 24 cases of grade IV or V (Croft’s) osteoarthritis (OA) who had undergone the same kind of arthroplasty during a 2 year period in Akhtar hospital in Tehran. These cases were matched in terms of gender and age, and were assessed by Harris hip score with 41(±22) months follow-up. The AVN cases had 30.86 (±7.5) and OA cases 47.88 (±12.6) years at surgery. Three patients from each of the above groups had sustained complications of either femoral neck or acetabular cup fracture and had required revision surgery. The average Harris hip score was 94(±7.2) in AVN and 91.2(±9.4) in OA group. The collective hip range of motion was 216(±6.2) in AVN and 196±(5.6) in AO patients. Metal-on-metal hip resurfacing gives similar satisfactory results in avascular necrosis and in osteoarthritis of hip joint in short-term, with no statistically significant difference.