AVASCULAR NECROSIS OF THE HIP TREATED BY HEMIARTHROPLASTY - RESULTS IN RENAL-TRANSPLANT RECIPIENTS

Osteonecrosis of the femoral head is a common complication in renal transplant recipients. Despite the young age of these patients, replacement arthroplasty is often used in treating symptomatic individuals. Between 1983 and 1990, 22 cemented biarticular hemiarthroplasties were performed in 16 consecutive patients with advanced osteonecrosis of the hip. The average interval from initial transplant to arthroplasty was 28 months (range, 11-63 months). The mean age at the time of arthroplasty was 40 years (range, 21-66 years), and all patients were treated with steroids and immunosuppressants at the time of surgery. The average preoperative Harris hip score was 27 points (range, 4-46 points). The mean follow-up period was 40 months (range, 24-71 months). All patients had improvement in pain. Eighty percent of the patients reported a slight or mild limp, although only 25% demonstrated a positive Trendelenburg sign. The average postoperative Harris hip score was 88 points (range, 71-96 points), with 9 hips rated excellent, 12 good, and 1 fair. One patient fractured her acetabulum 26 months after arthroplasty, which resulted in progressive subluxation of the prosthesis. It was revised to a total hip arthroplasty. Another patient developed symptomatic aseptic loosening after 30 months. Apart from this patient there was no other radiologic evidence of loosening in the remainder of the series. Only one patient had demonstrable acetabular protrusion. Twenty percent of the hips had asymptomatic heterotopic ossification. The early results of using a cemented, biarticular hemiarthroplasty in this young group of renal transplant recipients appear encouraging. There was no evidence that this prosthesis causes accelerated acetabular erosion or early loosening. It also has the advantage of preserving acetabular bone stock, which facilitates future revision.