LONG-TERM RESULTS OF PRIMARY TOTAL KNEE REPLACEMENT IN PATIENTS WITH HEMOPHILIA

Abstract

Background: The outcome of total knee replacement in patients with hemophilia has been variable. Several authors have suggested a relationship between high rates of late infection following total knee replacement in patients with hemophilia and a positive HIV status. The objective of this study was to evaluate the results of primary total knee replacements performed in a large group of hemophilic patients at a single institution by the same primary surgeon. Methods: The results of ninety primary total knee replacements performed in sixty-eight hemophilic patients between 1975 and 2001 were reviewed retrospectively. The HIV status and the CD4 count at the time of the surgery were recorded for fifty-three patients (seventy-one knees). Knee Society clinical and functional scores were determined for twenty-nine patients (thirty-eight knees) who were available for follow-up. Prosthetic survival was calculated with use of Kaplan-Meier survivorship analysis. Results: The overall prevalence of infection was 16%. Twelve knees required removal of components, and the reason for the removal was late infection in nine of them. The prevalence of infection in HIV-positive and HIV-negative patients was 17% and 13%, respectively (p = 0.5). When component removal for any reason, survival free of infection at any point, and mechanical failure were considered to be the end points, the ten-year survival rates were 83%, 77%, and 96%, respectively. The Knee Society clinical score was excellent or good for 80% of the knees, and the Knee Society functional score was excellent or good for 97% of the knees. Conclusions: Despite the anatomical challenges, the mechanical survival of total knee replacements in patients with hemophilia is quite good. However, the prevalence of infection after the total knee replacements was high. The prevention of late infection would substantially improve the long-term outcome of total knee replacements in this patient population. Level of Evidence: Therapeutic study, Level IV. See Instructions to Authors for a complete description of levels of evidence.