Twenty-year results of McKee-Farrar versus Charnley prosthesis.

The results of 107 consecutive McKee-Farrar and 70 Charnley total hip arthroplasties performed in 169 patients between 1975 and 1976 are reviewed. At an average followup of 20 years (range, 19-21 years), 29 patients with 20 McKee-Farrar and 11 Charnley prostheses were available for clinical and radiologic evaluation; 102 patients (107 hips) had died, 3 patients were lost to followup, and 5 patients (6 hips) were unavailable for review because of medical problems. There were 5 revisions for sepsis and 1 Girdlestone procedure for recurrent dislocation. Sixteen McKee-Farrar and 8 Charnley prostheses were revised for aseptic loosening, giving a 20-year aseptic probability of survival of 77% and 73%, respectively. Radiographic signs of loosening were present in 52% of the surviving prostheses. Clinical scores showed weak correlation with the radiographic loosening in both groups, and 18 McKee-Farrar and 8 Charnley prostheses were still considered satisfactory by the patients. The mean annual linear polyethylene wear was 0.12 mm. Osteolytic lesions were observed in association with 2 McKee-Farrar and 5 Charnley prostheses in surviving hips. The long term results of the McKee-Farrar prosthesis are comparable with those of the low friction arthroplasty in this series. Wear of the polyethylene bearing and accumulation of polyethylene particles in the periprosthetic tissue may become an increasing problem. Second generation all metal implants seem to be worth considering in patients with long life expectancy.