I. Postoperative rehabilitation stage 1 (within 2 weeks after surgery) Rehabilitation principles: this period is the early stage after surgery, there is a more obvious inflammatory reaction at the surgical site, and the joint capsule and muscle and tendon tissues have not yet healed. The focus of rehabilitation treatment is to reduce local inflammatory reaction, reduce swelling and pain, promote blood circulation, prevent infection, and prevent deep vein thrombosis in the lower limbs. Rehabilitation goal: to reduce post-surgical pain and swelling, with no significant swelling around the hip 2 weeks after surgery. Conduct muscle strength and mobility training at an early stage to avoid joint adhesions and muscle atrophy. Static training should be the main focus. 2 weeks after surgery, hip extension should be normal and flexion should reach 90°. (1) After surgery, the affected limb is placed in an abducted neutral position with a pillow placed between the legs and a pillow placed on the outside of the thigh to prevent external rotation. (2) After the anesthesia is released, active flexion and extension of the toe and ankle joint can be started, and ankle pump training can be performed: 5 minutes/group, 1 group/hour to promote blood and lymphatic reflux, reduce swelling and prevent deep vein thrombosis. (3) Muscle training: isometric contraction training of quadriceps, N cord and gluteal muscles was started on the 1st postoperative day: >300 reps/day. Do as many as possible without increasing pain. Start double bridge exercise exercises 1 week after surgery. Supine with feet apart and knees bent to elevate the glutes. 10 seconds/reps, 10 reps/day. Progressively carry out skinned resistance exercises for quadriceps and N cord muscles as appropriate. Muscle training should be performed without pain, and the frequency and intensity of exercises should be increased as appropriate according to the patient’s condition. (4) Joint mobility exercises: passive joint mobility exercises of the affected limb were started on the 1st postoperative day. CPM machine training, 2 times/day, 30 minutes/time. The mobility angle was gradually increased without pain or slight pain, and the flexion was less than 90°, and ice was applied for 20-30 minutes after the training. Active knee flexion and hip flexion exercises and hip abduction exercises were started on the 3rd postoperative day, avoiding internal retraction and internal rotation movements. (5) Weight bearing and position transfer: the patient should turn over to the healthy side, and a pillow should be held between the two legs. On the 3rd postoperative day, train the transfer from lying to sitting position in bed. One week after surgery, stand with the help of double crutches and practice walking with the help of double crutches or walker. The cemented type can be 100% weight-bearing and the non-pre-cemented type 20% weight-bearing, and gradually increase to 100% weight-bearing after 6 weeks. For mixed type, refer to non-cemented patients. (6) Pneumatic circulation pump treatment for the affected limb: promote blood circulation, reduce swelling and prevent deep vein thrombosis. Second, the second stage of postoperative rehabilitation (2-4 weeks after surgery) Rehabilitation principles: the skin has healed during this period, and the joint capsule, muscles and tendons have basically healed 3 weeks after surgery. The focus of rehabilitation treatment is to increase the strength of the muscles around the hip and the stability of the joint, and to increase the mobility of the joint. Rehabilitation goal: 4 weeks after surgery, periprosthetic muscle strength reaches grade IV-V, active hip extension is normal, hip flexion reaches 90°, and passive hip flexion reaches 110°. Normal weight-bearing standing and basic normal gait for non-cemented prosthesis patients (holding double crutches). (1) Muscle strength exercise Strengthen straight leg lift muscle strength training, straight lift after knee extension to bed or 30°, hold for 10 seconds, 10-20 times/group, 2 groups/day. Continue to strengthen the quadriceps, N cord muscle and gluteus muscle of the leather band resistance muscle strength training. (2) Active joint flexion and extension training Slowly and forcefully, flex the knee and hip with maximum active flexion, hold for 10 seconds and then slowly straighten. 10-20 times/group, 2 groups/day. Gradually increase the angle. Active hip extension training: single bridge exercise. Straight leg elevation of the healthy limb, knee and hip flexion of the affected limb, 10-20 times/group, 2 groups/day. 4 weeks after surgery, active hip extension was normal, hip flexion reached 90°, passive hip flexion reached 110°. Knee flexion and extension were normal. Start bicycle training, gradually increase the load and gradually reduce the height of the seat. 10-30 minutes/time, 2 times/day. (3) Balance and gait training Patients with cemented type continue standing balance training, and use computerized balance device for training if possible. The difficulty of training is from easy to difficult. Gait training from 4:00-3:00-2:00 gait. Non-cemented type partial weight-bearing, from ¼weight-½weight-100% weight gradually transition. Weight bearing on the affected limb on a health scale may be used to clarify the sensation of partial weight bearing. Weight loss gait training is performed using a weight loss trainer when available. In the 2nd-4th postoperative weeks, practice going up and down the stairs as appropriate, starting with the healthy side first when going up the stairs and the affected side first when going down the stairs. Bone cement type start to perform static squatting exercises with both legs against the wall. Third, the third stage of postoperative rehabilitation (the 5th-12th weeks after surgery) Rehabilitation principles: this period is the middle and late stage after surgery, the focus of rehabilitation is to further strengthen the muscle strength and joint stability around the hip, try to restore joint function, self-care of daily life, and gradually resume sports. Rehabilitation goal: 6 weeks after surgery, the periprosthetic muscle strength reaches grade V, and the active hip flexion and extension is normal. Normal gait at 8 weeks postoperatively, normal daily living ability at 12 weeks postoperatively, and able to perform appropriate sports. (1) Continue to perform paretic resistance muscle strength exercises for quadriceps, N cord and gluteus. Use the hip isometric resistance trainer to perform peripatellar resistance muscle strength exercises with progressive increase in resistance according to the condition of the affected limb. Resistance power cycling training with angle training; gradually increase the angle of the squat with increasing strength, 2 minutes/repetition, 10 seconds interval, 5-10 reps/set, 2-3 sets/day. Straddle training, including anterior-posterior and lateral straddle training. 20 reps/per set, 1 minute rest between sets, 4-6 sets in a row, 2 times/day. One-legged squat training on the affected side after the muscle strength is better. 20-30 times/group, 1 minute rest between groups, 2-4 groups/time, 2 times/day. (2) Continue active hip flexion and extension training, gradually increase the angle. Active hip mobility was basically normal at 8 weeks after surgery. (3) Continue the balance and gait training: non-cemented patients start the standing balance training 6 weeks after surgery. The training can be carried out with a computerized balance apparatus, and the difficulty of the training is from easy to difficult. Gait training for non-cemented patients should be carried out gradually without crutches. (4) At 12 weeks after the operation, the patients can take care of themselves in daily life, and gradually resume physical activities when the joint mobility and muscle strength around the hip are basically normal. Patients can walk, swim, bike, golf and other sports according to their own situation.