There are many factors that affect the results of ACL and PCL reconstruction: 1. Early or late surgery: The earlier the surgery, the better the post-operative results, because if the surgery is done late, the joint degenerates and ages, and all parts of the knee joint become lax, the surgical technique will not be as good as if the joint is not in an aged and worn state. 2. Surgical technique: The surgical technique is directly related to the surgical results. The surgical technique is directly related to the outcome. 3. The condition of the patient’s knee joint, the meniscus is severely torn and the cartilage is extensively peeled off during surgery, compared to the meniscus and cartilage without damage, the result is different. Li Anping, Department of Joint Surgery, Hainan Provincial People’s Hospital 4. Combined injuries of the patient’s knee: If combined with other ligament injuries (multiple ligament injuries) or combined with fractures of the tibial plateau and other parts of the knee will affect the outcome of the surgery, even if the surgery cannot be performed immediately, and for severe old tibial plateau collapse fractures, even ligament reconstruction surgery cannot be performed again. 5. Inadequate post-operative rehabilitation also affects the outcome of the surgery. If the postoperative rehabilitation is too aggressive, the ligaments may be lax. If the postoperative rehabilitation is too slow and painful, the knee joint may stick together.