Comparative long-term survivorship of uncemented acetabular components in revision total hip arthroplasty.

BACKGROUND

It is unknown whether the long-term survival of uncemented acetabular components in revision total hip arthroplasty varies according to component type. The purpose of this study was to compare the survivorship of historical and current uncemented acetabular components following revision total hip arthroplasty.

METHODS

The study population included 3236 patients who underwent 3448 revision total hip arthroplasty procedures with an uncemented acetabular component at a large United States medical center between January 1, 1984, and December 31, 2004. Patients were actively followed up at regular intervals to ascertain details of subsequent revision surgical procedures, including cup (metal shell plus liner) and liner revisions. The overall survival and the cause-specific survival of ten different acetabular components were compared with use of Cox proportional-hazards regression models, adjusting for age and sex.

RESULTS

A total of 605 repeat revisions, including 386 cup revisions, were performed. The corresponding overall survival rate at fifteen years was 69% (95% confidence interval [CI], 67% to 72%). Compared with titanium wire mesh designs, cup revision for aseptic loosening was significantly more common with beaded designs (hazard ratio [HR], 2.01; 95% CI, 1.44 to 2.80) but less common with trabecular metal designs (HR, 0.25; 95% CI, 0.06 to 1.04). There were no liner revisions for wear and/or osteolysis during a median of 5.2 years of follow-up of 534 total hip arthroplasties with cross-linked polyethylene liners, resulting in a significantly lower risk of wear-related revision with cross-linked polyethylene compared with conventional liners. Femoral head size and use of an elevated liner were not associated with the risk of repeat revision.

CONCLUSIONS

In the setting of revision total hip arthroplasty, cup survival was worse with beaded acetabular designs compared with titanium wire mesh or highly porous designs. Cross-linked polyethylene liners were associated with a reduced risk of wear-related liner revision.