Primary Stanmore total hip arthroplasty with increased cup loosening in rheumatoid patients.

We studied all Stanmore total hip arthroplasties (THA, n=325) implanted at our center between 1980 and 1990. Seven patients (seven hips), followed for less than 12 months, were excluded. Five hips were lost at follow-up. The mean follow-up was 117 (12-252) months. A total of 18 hips were revised, with median time between operation and revision 163 months. With revision as endpoint, a survival rate analysis was calculated. The mean survival for all hips was 82% at 18 years (95% confidence interval 64-101%). For hips with rheumatoid arthritis, the survival rate was 58%, whereas in osteoarthritic hips the rate was 95% after 18 years. A high proportion of acetabular loosening was seen in rheumatoid hips.