Revision Total Knee Arthroplasty Using the PFC Sigma Knee System

ABSTRACT

PURPOSE: We wanted to analyze the causes of revision and the clinical and radiographic results after revision total knee arthroplasty. MATERIALS AND METHODS: Thirty-eight knees in 34 patients underwent revision total knee arthroplasty using the PFC(R) Sigma revision system between March 1999 and May 2005. The average patient age was 71.2 years, and the average follow-up period was 6 years 7 months (range 4 years~10 years 2 months). We evaluated the time interval between the primary and revision arthroplasty and the causes of revision. The clinical outcomes were assessed using the knee score and the functional score of the Knee Society Scoring system (KSS system), and the radiographic measurements were assessed using the roentgenographic method of the American Knee Society. RESULTS: The mean interval between primary and revision arthroplasty was 6 years 3 months. The causes of revision included 25 cases of aseptic loosening and osteolysis, 7 cases of infection, 3 cases of joint stiffness and 3 cases of polyethylene problems. At the follow up, the mean preoperative knee and functional scores improved from 45.1 points to 84.5 and 37.2 to 78.2, respectively. Radiographycally, the average femorotibial angle was corrected from 2.2degrees in valgus to 6.5degrees. The radiolucency score was below 4 in all the cases. The complications after revision arthroplasty were 2 cases of superficial infection and 1 case of wound dehiscence with a skin defect. CONCLUSION: The main causes of revision arthroplasty were aseptic loosening and osteolysis. Satisfactory results were obtained using the posterior cruciate ligament and substituting the PFC(R) Sigma knee system with appropriately selected metal augmentation and an allograft. This study showed favorable results on long term follow-up.