More than Ten Years of Follow-up Results of Total Condylar Knee Prosthesis

Abstract

Sixty-one patients (83 joints) were available for this study, with a minimum of 10 years of follow-up. The average follow-up period was 146.5 months. In all cases, the tray of the tibial component was composed of polyethylene. The average weight of the rheumatoid arthritis patients was 45.8 kg and that of osteoarthritis patients was 54.1 kg. Clinical evaluation revealed that the greatest improvement was in pain relief. Range of motion revealed that extension improved from the preoperative mean of-12.6° to -2.3° postoperatively, while the flexion angle decreased from 106.3° to 92.4°. Postoperative radiographic evaluation was done on the appearance of radiolucent lines along the bone cement-bone interface of the tibial component. Radiographs taken 10 years after operation showed that 25.3% of the joints were grade I, 34.9% were grade II, 24.1% were grade III, and 15.7% were grade IV. Survivorship analysis, using aseptic loosening and deep infection as end-point criterion, gave a 10-year probability of survival of 98%. The long-term results of this series were very satisfactory. We found that total condylar knee arthroplasty was a safe, durable, and favorable procedure. One reason for this might be that the average weight of the patients in this study was considerably less than that reported outside Japan.