Note: Any postoperative rehabilitation program needs to be individualized according to the individual situation. Pre-operative stage 1, knee flexion and extension training; 2, muscle training: learn ankle pump, quadriceps isometric contraction training methods; 3, walking training with the aid of a walker. Second, the first postoperative stage: acute phase (days 1-5) 1, the goal: reduce swelling and pain, as far as possible, flexion and extension of the knee joint; active knee flexion ≥ 80 ° (seated position), straightening ≤ 10 ° (supine position) 2, measures: (1) CPM training: flexion of the knee began to reach 60 °, and gradually increase, 4-6 hours / day; (2) keep the knee in passive extension position 4-6 times a day, each time for 15-30 minutes. (3) Elevation of the affected limb; cold compresses after training (throughout the entire phase of rehabilitation); (4) strength training: isometric contraction of quadriceps, gluteus, N cord muscle, muscles around the ankle joint (ankle pump), straight leg raise, etc.; (5) ROM training: passive, active-assisted, and active movements; knee flexion and extension training; (6) partial weight-bearing training within the pain tolerance range with the assistance of a walker; (7) ADL (7) ADL training. Third, the second postoperative stage (2-8 weeks) 1, the goal: reduce swelling and pain, as far as possible to restore the knee joint activities: active assisted knee flexion ≥ 105 °, active assisted knee extension = 0 °, improve the muscle strength of the lower limbs, restore the normal gait; enhance the ability to independently engage in a variety of activities. 2.Cautions: avoid unassisted walking if there is gait tilt; only when the affected limb has enough muscle strength or good control can the legs be trained to alternate when walking up and down the stairs. 3, measures: (1) patellar luxation: improve patellar mobility; (2) continue ROM training: ROM, gastrocnemius muscle stretching training to improve the knee function; (3) continue muscle training: continue muscle strength training; multi-angle straight leg raising training; gradual closed-chain micro squatting and other training; straightening lag: closed-chain terminal knee training; (4) continue to raise the patient, cold compresses and other decongestive treatment; (5) ROM> 110 °, collapsed car training. (5) When ROM>110°, collapse training (forward and reverse); (6) Quadriceps muscle strength improvement, knee ROM>83°, up and down step training; (7) Balance/ proprioception training; (8) Single leg weight bearing, center of gravity transfer training. Fourth, the third postoperative stage (week 9-16) 1, the goal: maximum recovery of ROM, knee flexion to 117 ° 2, measures: (1) continue patellar luxation; (2) quadriceps strengthening training: gradually increase the height of up and down steps; squatting horse stance, squatting against the wall training; single-leg centrifugal stirrups training; (3) ROM training: quadriceps, N rope muscle stretching training; (4) collapsing the bike (4) Collapse training (forward leaning retrograde collapse training); (5) Balance/ proprioception training; (6) Walking and step up/down training; (7) According to the residual impairment, develop training focusing on the improvement of the residual impairment: terminal flexion/extension of the knee, weak quadriceps muscles, poor balance, etc.