Radiographic assessment
Bilateral knee and full-length lower limb standing X-rays were taken before the surgery, and bilateral knee radiographs were taken 24 h after surgery. Postoperative full-length lower limb standing X-rays were taken at the first follow-up. The mechanical femorotibial angle of both knees was measured using the full-length lower limb standing radiograph via digital image viewer software (General Electric Centricity Digital Imaging and Communications in Medicine Viewer 3.1.4., Chicago, Illinois, United States). One independent radiologist performed all radiographic evaluations twice to reduce intraobserver bias. The ICC was 0.76.