I. Postoperative Day 1 – Week 1 To prevent joint swelling, prolonged standing and walking should be avoided. Performing heat therapy is prohibited. 1. Ankle pump, do as much as possible. 2. Sitting knee extension (affected heel padded, toe up, knee vacated below), 30 minutes/time, 2 times/day, 2 weeks to reach full extension. 3. Muscular strength exercises: straight leg raising exercises. 4. Progressive weight-bearing to achieve pain-free unilateral weight-bearing of the affected limb. 5. Mobility exercises (can be started after removal of the cotton leg dressing after surgery): active flexion 0-90 degrees. 6.Ice pack (ice water mixture): ice pack for 20 minutes after mobility exercises. If you feel swelling, pain and fever in the joint, ice pack can be applied 2-3 times a day. II. 2-3 weeks after surgery (7-10 days after surgery to outpatient clinic for review and removal of stitches) Avoid repeatedly going up and down stairs until the lower limb strength is fully recovered (to control swelling). It is important to note that exercises and functional activities should be done to avoid pain. (i) Postoperative week 2 1. Mobility exercises and ice: active flexion 0-120 degrees 2. Strengthening muscle strength exercises (straight leg lift under resistance) 3. When walking without pain, you can take off the crutches. (ii) Postoperative week 3 1. Mobility exercises and ice: 0-140 degrees of active flexion. 2. Strengthen active flexion and extension exercises. 3. Start static squatting exercises. 4. Strive to achieve normal gait walking without pain. (a) Postoperative week 4-6 1. Mobility exercises and icing: the active and passive flexion angle is gradually the same as that of the healthy side. 2. Strengthen the muscle strength and start the knee exercises of 45 degree single leg semi-squat flexion and extension on the affected side. 3. Start step-up and step-down exercises. (2) Postoperative period 6-8 weeks 1. Fully resume all activities of daily life. 2, strengthen muscle strength and flexibility exercises, and gradually resume sports (jogging, swimming, rope skipping) Explanation of terms: ankle pump: hard, slow, full range of flexion and extension of the ankle joint static squat: legs apart, the distance between the two feet is slightly wider than the shoulders, the body remains upright position, can not lean forward, toes and knees are forward, not “inside and outside the eight”. At this point, both knees began to bend squat. The bending angle of both knees varies according to the patient’s physical condition and muscle strength. If the patient’s physical condition is good, good thigh muscle strength, squatting angle can reach 90 degrees; if the patient’s body and thigh muscle strength is weak, both knees can be lightly bent, this time the patient squatting position is higher, the patient more effort, with the practice of muscle strength and then increase the angle of bending the knee to the maximum angle of pain-free (not more than 90 degrees), 2 minutes -5 minutes / time, interval of 5 seconds, 5-10 times in a row / group. 5-10 consecutive times/group, 2-3 groups/day.