(1) Brace braking and weight-bearing: 24-hour brace protection at 0°; partial to full weight-bearing under brace protection at 0° and double crutch support as tolerated (2) Muscle strength training: 15 min 2 times/day isometric contraction of quadriceps; 15 min 2 times/day isometric contraction of N cord; 15 min 2 times/day isometric contraction of hip adductor. (3) Mobility training: patellar movement (internal, superior and inferior) 15 min 2 times/day; passive knee movement from the 2nd week, increasing knee flexion mobility by 15° daily to reach knee flexion ≥90°. (1) Brace braking and weight-bearing: remove the brace at rest, and perform full weight-bearing with a single crutch under the protection of the brace (0-30° position) during activities. (2) Muscle strength training: quadriceps exercise with brace, resistance contraction of N cord muscle, heel lift training. (3) Mobility training: full range of passive activities (4) proprioceptive training: stationary bicycle for 15 min 2 times/day (non-resistance). (1) Brace braking and weight-bearing: full weight-bearing walking exercise with the brace protection (0-30° position). (2) Muscle strength training: (as above) (3) Mobility training: passive activity up to 150° (4) Proprioceptive training: stationary bicycle 15 min 2 times/day; balance board or cushion (single leg, brace protection) 15 min 2 times/day (4) After 4 months postoperatively: remove brace, full weight bearing, active full range of knee activities (flexion and extension, half squat, lateral stepping, etc.), 6 months Start jogging at a uniform speed and return to normal exercise at about 1 year. Note: Rehabilitation may aggravate the swelling of the lower extremity, so please rest with the lower extremity padded in a lying position, and apply ice for 1 week after surgery, and then immediately after exercise.