Fig. 6

A 61-year-old male patient showed left knee osteoarthritis with hip-knee-ankle angle 7.3° genu varum deformity. The ankle joint line obliquity was 9.13°. B The conventional mechanical axis after opening-wedge high tibial osteotomy (OWHTO). C The true mechanical axis after OWHTO. D The postoperative weight-bearing line (WBL) ratio in the hip-to-talus radiograph after OWHTO was 61.1%, and that of the WBL ratio in the hip-to-calcaneus radiograph after OWHTO was 62.3%. There was no significant difference between the conventional mechanical axis and the true mechanical axis