High tibial osteotomy with fixation by a blade plate for medial compartment osteoarthritis of the knee.

Surgical techniques were described on tibial osteotomy above the tuberosity, the fragments of which were fixed with a Koshino blade plate. Postoperative clinical results on 176 knees with medial compartment osteoarthritis of 138 patients with an average age of 62.1 years were excellent in 110 and good in 55 knees with an average of 5.5 years' follow-up. The best knee score was obtained in the knee with postoperative limb alignment of 6 to 15 degree valgus angulation (standing). The results were satisfactory, especially in postoperative management, which was much easier with the Koshino blade plate fixation than with other methods. The sinking of the osteotomy site was checked through observation of screw movement in the slot of the plate during postoperative management in 53 selected knees, and the averaged distance of sinking was 3.9 +/- 2.5 mm. The time of mechanical bone union judged by cessation of sinking averaged 12.9 +/- 6.2 weeks after osteotomy.