REVISION OF UNICOMPARTMENTAL ARTHROPLASTY OF THE KNEE - CLINICAL AND TECHNICAL CONSIDERATIONS

In 73 unicompartmental arthroplasties of the knee that were revised, t he major causes of failure were progression of arthritis and implant f ailure. The interval between the primary and revision averaged 56 mont hs. Eighty-eight percent were revised to a variety of total condylar p rostheses. Bone loss was classified by defect at the end of preparatio n. In 31 patients, there were none; in 17, the defect was in either th e femur or the tibia; and in 25, there were defects in both the femur and the tibia. Forty-seven of these defects were small and contained, presenting little problem. Twenty defects were either large, contained , or peripheral, requiring reconstruction. Fifteen knees were lost as a result of death (but there had been satisfactory knee function); 2 w ere lost to follow-up evaluation, and 3 have required further revision . Seventy-nine percent of the surviving knees had excellent or good kn ee function at an average follow-up period of 56 months.