1, the first week after surgery: straight leg elevation training: supine position, knee straight, elevate the lower limb to 30-45 degrees, maintain for 10 seconds and then lower, repeatedly. Do this twice daily for 30-60 minutes each time. Weight-bearing activities and knee extension and flexion activities can be performed if pain allows. 2.Week 2-3 after surgery: straight leg raising training, 2 times a day, 30 minutes each time. On this basis, knee extension and flexion mobility training should be strengthened, generally requiring 90 degrees of flexion by the third week after surgery. 3.Four weeks after surgery: further increase the knee flexion mobility, generally require the knee flexion to exceed 120 degrees at 6 weeks after surgery, twice a day for 15 minutes each time, while leg compression training to ensure that the knee joint can be fully straightened. The supine straight leg raising activity was replaced with active knee extension in the seated position. Begin with empty leg exercises, and after some recovery of muscle strength, practice hanging weights at the ankle until you can hang 5KG weights at the ankle. The training time was 15 minutes twice a day. Increase the one-legged weighted half-squat training on the affected side, with a half-squat range of 0-45 degrees. Begin with a double-legged half-squat, then transition to a single-legged half-squat on the affected side, twice daily for 30 minutes each time.