Postoperative rehabilitation: The affected knee was immobilized for 12 weeks using an external fixation brace. After the postoperative anesthesia effect, the patient was instructed to perform muscle exercises, such as ankle pump, quadriceps tendon isometric exercises, straight leg raise exercises, etc. After 1 week of postoperative period, when the inflammation gradually subsided, the brace was temporarily removed and the patient was instructed to passively practice knee flexion in bed, gradually increasing the flexion angle by 15 to 25 degrees per week, and after 4 weeks the knee could be flexed to about 90 After 4 weeks, the knee can be flexed to about 90°; during this period, the patient must wear a brace on the floor, be fixed in the straight position and walk with a cane. Weeks 4-8: Instruct the patient to practice muscle strength exercises; instruct the patient to actively practice knee flexion in bed, gradually increasing the practice angle to the extent that no pain is apparent; adjust the angle of the brace worn on the floor, increasing by 15° per week, and adjust the angle of the brace to 60° by week 8, and walk with crutches. Weeks 8-12: Instruct the patient to exercise the functional activities of the affected knee, such as leg hooking in the prone position, squatting with the back against the wall, etc.; adjust the angle of the brace on the ground by 15° per week, and adjust the angle of the brace to 120° by week 12, and walk with crutches.