Revision surgery for failed surface arthroplasty of the hip.

In 17 cases of revision surgery performed for failed surface arthroplasty of the hip at UCLA medical center, the minimum follow-up period was six months (average, 22 months). Causes of failure included aseptic loosening (15), sepsis (1), and unexplained pain (1). High-risk groups include those with deficiencies of bone stock, congenital dysplasia, coxa vara, and osteonecrosis. Nine hips were resurfaced and eight converted to conventional arthroplasties. The clinical results of revision and conversion were comparable with those of conventional revision surgery but less satisfactory than those of primary surgery. Fewer technical problems and complications were encountered when compared with conventional revision. The length of operation and blood loss were less, and there were no instances of sepsis, nerve palsy, instability, or femoral fracture. The major complication has been recurrent loosening, with a 17% incidence of failure requiring conversion to conventional replacement. The results, as in conventional revisions, have been suboptimal. The technical complexities have been many, especially with respect to femoral and acetabular revision.