SURVIVORSHIP OF UNCEMENTED PROXIMALLY POROUS-COATED FEMORAL COMPONENTS

Three hundred seventy-five consecutive total hip arthroplasty revision s 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. Mo derate or severe pain was present in 23% of surviving hips, and radiog raphic evidence of femoral loosening was present in 38% of surviving h ips at the most recent followup. At 8 years, survivorship free of revi sion for aseptic femoral failure (for loosening or osteolysis) was 58% (95% confidence intervals, 44.3%, 69.6%); survivorship free of asepti c femoral loosening (revision for aseptic loosening or radiographic lo osening) was 20% (95% confidence intervals, 12%, 27%); and survivorshi p free of symptomatic femoral loosening (revision for aseptic loosenin g or radiographic femoral loosening with moderate or severe pain) was 45% (95% confidence intervals, 32.3%, 56%). More severe preoperative b one loss correlated with poorer survivorship free of aseptic loosening and subsidence of greater than or equal to 5 mm. Differences among th e prosthetic-type groups with respect to patient's age, gender, and bo ne loss severity precluded direct comparison of performance for each p rosthetic type; however, all the prostheses had a significant rate of rerevision and aseptic loosening. Stable long-term fixation with the p roximally porous-coated femoral components used in this series was not achieved on a predictable and reproducible basis. The damaged, weaken ed bone often present in the proximal femur during revision probably d oes not provide an optimal environment for sturdy initial or longterm biologic fixation of these devices that rely on the proximal femoral b one for fixation.