Twenty-Year Follow-up of the AGC Total Knee Arthroplasty

The long-term successes of total knee arthroplasty (TKA) are multifactorial, including patient, surgical, and implant factors. The purpose of this study was to examine the 20 year follow-up of the AGC (Biomet, Warsaw, Ind) TKA. A total of 7760 AGC TKAs were performed from 1983 to 2004, and knees with minimum 2-year follow-up were studied. The 20-year survivorship was 97.4% with no implants being revised for polyethylene wear or osteolysis. Age below 70 years was associated with increased survival (99.5%) (P = .0002), whereas preoperative valgus alignment (94%) (P = .0015) and a diagnosis of osteonecrosis (95.6%) (P = .0409) decreased survivorship. Age less than 55 years (P = .0788), preoperative varus alignment (P = .1250), rheumatoid arthritis (P = .2085), and sex (P = .7540) were not statistically associated with failure. We attribute the success of the AGC implant to its relatively unconstrained articular geometry and the durability of a nonmodular metal-backed tibial component with compression-molded polyethylene.