Abstract
Eleven unicompartmental knee arthroplasties in 10 patients who had continued to have progressive medial compartmental osteoarthritis after a high tibial osteotomy were evaluated retrospectively. The age at osteotomy was 63 years and the average interval between osteotomy and arthroplasty was 6.6 years (range : 1.5-17.5) . The average length of follow-up after arthroplasty was 6.4 years. The knee score of the Japanese Orthopaedic Association was 56 points at osteotomy, 56 points at arthroplasty, and 75 points at the final follow-up. Limb alignment was investigated with the standing femoro-tibial angle. Angulation averaged 185 degrees at osteotomy, 183 degrees at arthroplasty, and 178 degrees at follow-up. Radiographic examination showed that one patient had loosening of the tibial component, but no other loosening was identified. Radiographic progress of osteoarthritis was seen in 9 of 11 knees at the time of arthroplasty. Compared with the procedures for total knee arthroplasty, those for unicompartmental arthroplasty were notably easier to perform even in knees after a failed tibial osteotomy.
