Rehabilitation training principles: painless, ice, slow movement muscle 1, swing the instep up and down, contract the calf muscles (ankle pump). 2, Tighten the thigh muscles when the knee is straightened, lasting 5~10 seconds. 3, Straight leg raise, 30~50 degrees, for 5~10 seconds. Mobility Heel slide, seated knee flexion and extension (passive). Within 1 week: can fully straighten the knee joint (0°). Within 6 weeks: normal flexion angle is achieved or approached. Weight bearing, walking Partial weight bearing with crutches. Criteria for abandonment of crutches: can straighten, 100° of flexion, can lift straight leg, no swelling, no pain when walking. Cold compress: Within 1 week: every 2-3 hours, about 5-6 times/day, no ice at night. After 1 week: according to the degree of swelling, the frequency can be appropriately reduced, about 2~3 times/day. Throughout the rehabilitation phase: ice packs immediately after each mobility training. 10-15 minutes each time Postoperative suture removal: about two weeks after the operation, the surgeon outpatient review, suture removal.