Abstract: Objective To compare the clinical outcomes of high tibial closed osteotomy and open osteotomy, as well as the changes in posterior tibia slope and patellar height. Methods A total of 120 patients (155 knees) with high tibial osteotomy performed from January 2017 to June 2018 were collected. Twenty cases (25 knees) used lateral tibial closed wedge osteotomy (LCWHTO), and 100 cases (130 knees) used medial tibial open wedge osteotomy (MOWHTO). The follow-up time was 20.7 months and 18.9 months respectively. Lysholm score and joint mobility (ROM) were evaluated at the last follow-up. The changes of mechanical axis deviation (MAD), proximal medial tibial angle (MPTA), posterior tibia slope(PTS) and M-K index were compared between the two groups of patients. Results In the LCWHTO group, the M-K index was 0.79±0.07 after operation and 0.78±0.08 after operation. There was no change before and after operation 0.78±0.05 before MOWHTO operation was significantly higher than 0.75±0.05 after operation (P＜0.05). The postoperative PTS in the LCWHTO group was 8.1°±3.4°, which was significantly lower than the preoperative 10.8°±3.0° (P＜0.05); the postoperative PTS in the MOWHTO group was 10.9°±4.0°, and 10.2°±3.1° before operation. No change before and after operation. Conclusions Both LCWHTO and MOWHTO can obtain satisfactory clinical outcomes. LCWHTO reduces PTS and has no effect on the patellar height. MOWHTO has no effect on PTS, but it reduces the patellar height. The choice of osteotomy should be individualized according to the characteristics of the patients.

Key words: high tibial osteotomy, opening wedge, closing wedge, posterior tibial slope, patellar height