After ACL injury, due to the characteristics of its own structure, it is not possible to treat it by suturing. In order to restore the function of the ACL, it is necessary to reconstruct a ligament in the previous position, also known as anatomical reconstruction. The materials needed can be roughly classified according to the source: 1. autologous tendon; 2. allograft tendon; 3. autologous + allograft; 4. artificial ligament. In clinical practice, we often encounter patients who have difficulty deciding on the choice of grafts and are very “torn”, because each has its own advantages and disadvantages, which often makes it difficult to choose, and some people are even still hesitating until the operating room. I. Autologous ligaments: 1. patella-patellar tendon-bone (BPTB or BTB): BTB reconstruction material is easier to heal, but there are complications such as postoperative kneeling pain, anterior knee pain and possible patellar fracture complications. 2. thin femoral muscle-semi-tendon tendon (also known as N cord tendon) is the most representative graft among autologous tendons, with fewer postoperative complications and no functional loss after harvesting in 90% of patients. The greatest advantage of autologous tendons is that they are “economical” and there is no fear of “immune rejection” or “disease transmission”. Although there is no evidence that autologous tendon harvesting has a significant impact on the patient’s function, the “natural talent”, “lack of own structure”, and “fear of possible loss of function ” makes some patients and their parents refuse to use autologous tendons. Second, allograft tendons Allograft tendons are taken from a wide range of cadavers, and grafts for use can be obtained from multiple locations throughout the body. There are only a few state-approved commercial companies supplying them, and the safety of the source should be guaranteed. In addition to patella-patellar tendon-bone and thin femoral muscle-hemitendinous tendon, allograft tendons such as Achilles tendon and anterior tibial tendon can be used. The Achilles tendon and anterior tibial tendon are ideal for ACL grafts because of their thick tendon structure, and the biggest advantage of allograft tendons is that they avoid “tearing down the east wall to make up for the west wall”. The biggest advantage of allograft tendon is that it avoids the need to “tear down a wall to make up a wall”. The disadvantage is that it “increases the cost of medical treatment”. Patients often ask whether the allograft tendon will be rejected. It should be said that the immune rejection of allogeneic tendons treated by deep cryogenic treatment is relatively small, and in our experience of dozens of cases each year, no significant rejection has been found. Third, autologous + allograft Some patients find that the diameter of the autologous ligament is small (because the average diameter of the anterior cruciate ligament should be 10 mm) due to development and other reasons, and it can not fully meet the force after reconstruction, at this time, you can choose a thicker allograft tendon plus an autologous semitendinosus tendon to achieve sufficient diameter to meet the force of the reconstructed ligament after surgery, without failure after reconstruction, and also can save A part of the medical costs, from our clinical see good results. The artificial ligament currently used in the Chinese market is the French LARS ligament, the biggest advantage of the artificial ligament is the early movement. This is undoubtedly a blessing for professional athletes, for them, early recovery of sports means “income”. Of course, artificial ligaments are also a good choice for people who work under a lot of stress, who are eager to recover from work, and so on. But artificial ligaments have their own “weaknesses” and are not suitable for all patients. 1, artificial ligaments should be used in acute ligament injuries, or chronic injuries with stump preservation, such as the lack of autologous ligament stump cases, will aggravate the ligament wear. 2, artificial ligaments and the bone wall is fixed by screw extrusion, artificial ligaments and bone wall It is never possible to obtain healing between the artificial ligament and the bone wall. If problems such as osteoporosis or bone resorption in the bone tunnel wall occur, the screws may loosen, leading to loosening of the ligament. 3. The reconstruction of the artificial ligaments must find the “equal length” of the femoral and tibial tunnels in order to ensure that the ligaments remain tense during the postoperative knee movement, otherwise either the mobility will be affected or the joint will be unstable due to ligament laxity at a certain angle. Therefore the choice of graft is made according to their own situation, but in addition to the choice of ligament, the most critical thing to reconstruct the ACL is to choose the position of the tibial and femoral tunnels and the method of graft fixation, and a very critical thing is to guide the patient’s functional exercise after the operation, and we wish the reconstructed patient to get a good knee function.