We radiologically evaluated 46 knees undergoing interlocking wedge osteotomy for osteoarthritis between 1998 and 2000 at Kyushu Kosei-Nenkin Hospital. They started ROM exercise by CPM one week after the operation and partial weight bearing at three weeks. Their JOA Score significantly improved from 62.1 to 83.3, %MA improved from 12.0% to 66.3% ant FTA improved from 181.3° to 168.5° seven cases who had loss of correction of osteotomy, of which three had loss of correction within two months after operation, and four cases after two months. The etiology of loss of correction is considered to be bone weakness of the medial malleolous and insufficient lateral staple fixation for maintaining correction during bone union.
