Assessment of longterm benefit of total hip replacement in patients with ankylosing spondylitis.

Clinical and radiographic follow-up examinations were obtained on 12 patients with ankylosing spondylitis (AS) who had undergone total hip replacement (THR). Four of these patients had bilateral THRs performed. The mean follow-up of these 16 THRs was 89 months (range 7-144 months). The THR had achieved excellent pain relief in 15 hips. Postoperative ankylosis did not occur. One arthroplasty has to be removed because of the development of protrusio acetabulum.. Radiographic follow-up was obtained in 14 hips. Six were found to have moderate periarticular ossification which did not significantly affect function. In our experience the risk of postoperative periarticular ossification developing in patients with AS is not a contraindication to hip replacement.