(a) Postoperative day 1 Start moving toes and ankle dorsiflexion and dorsiextension exercises (30′ interval) as much as possible without increasing pain, i.e., do leg extension exercises to tighten and relax the thigh muscles, contract 500 times a day, spread out to morning, noon and night. Each time slowly hold for 5-10 seconds. Start straight leg raising exercises: 1 set of 10-20 times per day, each leg raising lasts 1-3 minutes. After 24 hours postoperatively, you can walk on the ground with the help of crutches, but only for necessary activities such as going to the toilet. (B) 2-6 days after surgery 1. Continue quadriceps isometric exercises. 2.Continue straight leg raising exercises, 3 sets per day, 10-20 times per set, each leg raising lasts 1-3 minutes. 3.Start back leg raising exercises, lying prone (face down), straight leg raising after knee extension until the toe is 125px from the bed, hold for 5 seconds. 30 times/set, 3-4 sets/day. If the pain and swelling is not obvious, you can support the single crutch or do not use the crutch to go down to the ground, but do not encourage more walking, limited to the toilet. 4.Start single-leg standing balance exercise: 5min/set, 2-3 times/day. 5.Bedside flexion and extension knee exercise: active knee flexion up to 90°. (C) 1 week after surgery 1.Continue the above exercises. 2.Active flexion greater than 90°, can walk short distance without crutches. 3.Increase the resistance muscle training as the situation allows. (D) 1-6 weeks after surgery Strengthen mobility and muscle exercises; improve joint control and stability; start to resume daily activities. Care should be taken to control the amount of exercise to avoid joint swelling and fluid accumulation. If the joints feel swollen and warm after the exercises, ice should be applied promptly! 1.Continue to strengthen the above functional exercises. 2.Active flexion 120-130°. 3.No significant swelling or pain in the joint, then you should walk with a normal gait as much as possible. 4.Resistance knee extension exercise: use sandbag as the load (1kg), if there is joint swelling and pain after the exercise, you can apply ice. 5.Start squatting against the wall: back against the wall, feet shoulder-width apart, toes and knees forward, no “internal and external figure of eight”, gradually increase the angle of squatting (less than 90°), each time for about 20 seconds, each interval of 5 seconds, 5-10 times/group. 2-3 groups/day. (E) 6-8 weeks after surgery 1.Can actively flex and extend up to the same as the healthy side, and no pain. 2.Can complete all daily activities. Such as going up and down stairs, riding a bicycle. 3.Start pedaling exercises. 4.Start swimming. (6) 2 months-3 months after surgery Purpose: To fully resume all daily activities. Strengthen muscle and joint stability, and gradually resume exercise. Attention should be paid to the specific situation to avoid joint damage. 1.Start jogging. 2.Start lateral straddle jump exercises. 3.Athletes begin to practice basic movements in special sports, and wear knee pads for protection when necessary during exercise. Caution: It is normal to have pain during the rehabilitation process. If there is persistent swelling, increased skin temperature with fever; or if the joint mobility does not progress, contact the attending physician in a timely manner.