To evaluate the clinical and radiographic outcomes of high tibial open wedge osteotomy combined with arthroscopic surgery in patients with medial unicompartmental osteoarthritis.

Between January 1999 and May 2002, 29 patients with 30 cases were treated with high tibial open wedge osteotomy combined with arthroscopic surgery for the treatment of osteoarthritis. The mean age of the study group was 44.7 years old (range, 20 to 56 years old). 4 cases with more than 1 cm openings were treated by autologous bone grafts, and another 26 cases were treated by Puddu plates alone after osteotomy. The clinical assessment was performed using the Hospital for Special Surgery (HSS) knee rating system. The radiologic analysis was performed by measurement of the femorotibial angle and posterior inclination of the tibial articular surface.

The mean knee rating score by the HSS knee rating system improved from 64.7 points (range, 52.0 to 69.5 points) to 82.4 points (range, 78 to 90) at the last follow-up. Radiologic bone union was accomplished in all cases. Preoperative varus angles of 6.3 ° (range, 3.5 to 8.0 °) and posterior inclinations of 6.6 ° (range, 5.0 to 7.3 °) improved, on average, to postoperative valgus angles of 8.2 ° (range, 5 to 10 °) and posterior inclinations of 7 ° (range, 5.0 to 8.5 °). At the last follow-up valgus angles had improved, on average, to 7.3 ° (range, 4.5 to 9.0 °).

High tibial open wedge osteotomy combined with arthroscopic surgery significantly improved knee joint function.