I. Points to note before rehabilitation 1. The presence of anterior knee pain during functional exercises is inevitable. If the pain can subside to the original level within half an hour of the exercise stopping, it will not cause damage to the tissue and should be tolerated. 2, plyometric exercises should be concentrated until the muscles feel sore and fatigued, and then proceed to the next group after sufficient rest. The number of exercises, time, load depending on their own situation, and should be practiced at the same time the healthy side. The improvement of muscle strength and muscle capacity is the key factor of joint stability, and it is expected to be practiced carefully. 3, in addition to the surgical limb brake protection, the rest of the body parts (such as the upper limb, waist and abdomen, the healthy side of the leg, etc.) should be practiced as much as possible to ensure physical quality, improve the overall level of circulation and metabolism, and promote the recovery of the surgical local. 4, early joint mobility (flexion, extension) exercises, only once a day, and strive to improve the angle can be, avoid repeated flexion and extension, multiple exercises. If the flexion angle does not progress for a long time (>2 weeks), there is a possibility of joint adhesions, so we should pay great attention to it and consult the attending physician in time. 5. Apply ice for 20~25 minutes each time, 4~6 times a day. If the joint is swollen and hot, the number of ice packs can be increased. It can be increased 1 time after exercise. 6.The swelling of the joint will accompany the whole exercise process, and it is normal that the swelling does not increase with the angle exercise and activity, until the angle and muscle strength basically return to normal swelling will gradually subside. Sudden increase of swelling should adjust the exercise and reduce the amount of activity, and consult the attending doctor when it is serious. Rehabilitation procedure 1. Protection period: 1 day to 4 weeks after surgery Purpose: to reduce pain and swelling; early muscle strength exercises; early weight-bearing; early mobility exercises to avoid adhesions and muscle atrophy. 2.Resumption of weight-bearing period: 5~8 weeks after surgery This period should not be too much walking, otherwise it will easily lead to joint swelling and fluid accumulation, which will affect functional recovery and tissue healing. 3.Resume activity period: 9 to 12 weeks after surgery Eight weeks after surgery, the knee can be passively flexed more than 120° and active knee activity can be practiced on its own. 4. Resumption of movement period: 3 months later Purpose: Full resumption of movement or strenuous activity. Gradually resume strenuous activities, or special training. Strengthen the muscle strength and the stability of the joint in running and jumping. Through the test, the affected muscle strength reaches 85% or more of the healthy side, no pain in sports, no obvious swelling, then can fully resume sports.