Fig. 1

Perioperative change of the joint line convergence angle (JLCA) preoperatively (Pre-op), immediately under general anesthesia postoperatively (0 day), 2 days, and 1 month postoperatively in closed wedge high tibial osteotomy (CWHTO; a) and opening wedge high tibial osteotomy (OWHTO; b). Decrease of the JLCA by opening of the medial joint space and closing of the lateral joint space is shown at 0 day in CWHTO (a) and at 2 days in OWHTO (b), and it is maintained thereafter