Unicompartmental knee arthroplasty for medial gonarthrosis: 5 to 9 years follow-up evaluation of 77 knees.

A total of 77 knees in 60 consecutive patients were operated on for medial gonarthrosis using a cemented porous coated anatomical (PCA) unicompartmental knee arthroplasty. Their average age was 71.3 years; 11 were men and 49 women. Clinically, the results in 67 knees were rated as being good to excellent, with mean preoperative and postoperative flexion of 123 and 122 deg, respectively. No deep infections or deep venous thrombosis occurred, but there was one dislocation of the femoral component. Overall clinical and radiographic results were satisfactory in 88% at 7.0 years' follow-up. Kaplan-Meier survivorship analysis indicated that the failure rate of unicompartmental knee arthroplasty was 12% at average follow-up. In patients aged 70 years or more, unicompartmental knee arthroplasty for medial gonarthrosis should be considered an excellent alternative to high tibial osteotomy.