Long-term review of ring total hip arthroplasty.

In a five- to 12-year follow-up survey of 179 sequential cementless Ring metal-on-metal total hip arthroplasties, 55 (31%) of the patients were found to have died as a result of nonorthopedic conditions. Analysis of the records demonstrated that 20% of these patients had had poor results attributable to pain. Of the remaining 124 patients, 116 (94%) attended for full clinical and radiologic review yielding a total of 154 hips. Using Ring's classification, 75 hips were judged to have excellent or good results. Forty-one hips were graded as fair or poor as a result of pain, and an additional 15 hips were revised for symptomatic loosening. There were five cases of Brooker Grade IV periarticular ossification, four cases of gross metal reaction requiring prosthetic removal, and two cases of infection. There was considerable variation in the radiographic appearance of the hips, and at times radiographic changes were inconsistent with clinical symptoms. Eleven of the revised hips were converted to longer and larger-diameter uncemented Ring femoral components. Nine of these yielded only fair or poor results at the time of review, whereas both cases in which the femoral component was cemented were associated with good results.