Higher cumulative revision rate of knee arthroplasties in younger patients with osteoarthritis.

This study was designed to test the hypothesis that younger patients treated for osteoarthritis and similar conditions using total knee arthroplasty and unicompartmental knee arthroplasty have a lower implant survival rate when compared with older patients. Previous studies have been done on a small number of patients and only included the younger patients. In many cases patients treated for rheumatoid arthritis have been included in the studies and exceptional survival rates have been reported. The current study compared the cumulative revision rate of the components in 33,251 patients older than 60 years and 2606 patients younger than 60 years treated with total knee arthroplasty or unicompartmental knee arthroplasty for osteoarthritis or similar conditions. Cox regression was used to compare the risk for revision between the two age groups and between gender and the effect of year of operation. The results showed a higher cumulative revision rate for the group of younger patients in all statistical analyses and the risk ratio for revision was significantly lower for the group of older patients. The risk for revision decreased for both groups when considering the year of surgery. This is probably attributable to better implant components and surgical techniques.