Survivorship of Uncemented Proximally Porous-Coated Femoral Components

Three hundred seventy-five consecutive total hip arthroplasty revisions done using proximally porous-coated femoral components of 6 designs were reviewed a mean of 4.7 years after surgery. Fifty-nine hips have been rerevised for aseptic femoral loosening, and 4 for osteolysis. Moderate or severe pain was present in 23% of surviving hips, and radiographic evidence of femoral loosening was present in 38% of surviving hips at the most recent followup. At 8 years, survivorship free of revision for aseptic femoral failure (for loosening or osteolysis) was 58% (95% confidence intervals, 44.3%, 69.6%); survivorship free of aseptic femoral loosening (revision for aseptic loosening or radiographic loosening) was 20% (95% confidence intervals, 12%, 27%); and survivorship free of symptomatic femoral loosening (revision for aseptic loosening or radiographic femoral loosening with moderate or severe pain) was 45% (95% confidence intervals, 32.3%, 56%). More severe preoperative bone loss correlated with poorer survivorship free of aseptic loosening and subsidence of > or = 5 mm. Differences among the prosthetic-type groups with respect to patient's age, gender, and bone loss severity precluded direct comparison of performance for each prosthetic type; however, all the prostheses had a significant rate of rerevision and aseptic loosening. Stable long-term fixation with the proximally porous-coated femoral components used in this series was not achieved on a predictable and reproducible basis. The damaged, weakened bone often present in the proximal femur during revision probably does not provide an optimal environment for sturdy initial or long-term biologic fixation of these devices that rely on the proximal femoral bone for fixation.