The only way to restore the structural continuity of the ACL is to “reconstruct” it, that is, to “rebuild a ligament”. Just like building a house requires bricks and tiles, reconstruction of the ACL also requires “building materials”. The materials can be roughly classified according to the source: 1) autologous tendon; 2) allograft tendon; 3) artificial ligament. In clinical practice, we often encounter patients who have difficulty deciding on the choice of graft and are very “torn”, as each has its own advantages and disadvantages, which often makes it difficult to choose, and some even hesitate until the operating room. I would like to give a brief overview of the advantages and disadvantages of different grafts for the majority of patients. First, I would like to talk about autografts. Patella-patellar tendon-bone (BPTB or BTB) and thin femoral muscle-hemitendinosus tendon (ST-G, also known as N-cord tendon) are the most representative grafts among autografts. In contrast, the ST-G has fewer postoperative complications and does not cause loss of function in the vast majority of patients, but some domestic articles have reported that it may have some effect on soccer defenders, i.e., it may have a slight effect on “running backwards. This means that it may have a slight effect on “running backwards”. The biggest 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 tendons have a significant impact on the patient’s function after harvesting, the “natural talent”, “lack of own structure”, and “fear of possible loss of function ” has caused some patients and their parents to refuse the use of autologous tendons. However, frankly speaking, there is no significant difference in the ultimate functional recovery after surgery in patients with autologous or allograft tendon reconstruction. Allograft tendons are widely available, taken from cadavers, and grafts for use can be obtained from multiple locations throughout the body. Currently only a few nationally approved commercial companies supply them, and it should be said that the safety of the source is guaranteed. In addition to BTB and ST-G, allograft tendons such as Achilles tendon and tibialis anterior tendon can be used. The Achilles tendon and anterior tibial tendon have thick tendinous structures and are ideal for ACL grafts, but they cannot be taken in the patient’s own body because they can cause disability. The biggest advantage of allograft tendons is that they do not have to be removed. The disadvantage is the “additional medical cost”, which is about 10-20,000 RMB for an ACL reconstruction. Patients often ask whether the allograft tendon will be rejected. It should be said that the immune rejection of allograft tendons is relatively small, and in our experience of hundreds of cases per year, very few cases occur. Whether it is an autologous tendon or an allograft tendon, there is a process of remodeling after surgery, so you should not participate in strenuous exercise for six months to one year after surgery to avoid relaxation or re-rupture if the tendon does not reach satisfactory biomechanical properties with the bone and inside the tendon. In contrast, artificial ligaments solve this problem very well. The artificial ligament does not have the problem of reshaping, it is fixed by extruding the artificial ligament on the bone wall with metal screws, just like “hanging a painting on the wall with nails”. Therefore, the biggest advantage of artificial ligaments is early movement. This is certainly a boon for professional athletes, for whom early return to sport means “income”. Of course, artificial ligaments are also a good choice for people who work under a lot of stress and who are eager to recover. However, artificial ligaments have their own “weaknesses” and are not suitable for all patients. First of all, artificial ligaments should be used for acute ligament injuries or chronic injuries with preserved stumps. The lack of an autologous ligament stump may increase ligament wear. Second, as stated earlier, fixation is obtained between the artificial ligament and the bone wall by screw extrusion, and healing between the artificial ligament and the bone wall can never be obtained. Then, if problems such as osteoporosis or bone resorption in the bone tunnel wall occur, the screws may loosen, which in turn may lead to loosening of the ligament. Finally, the use of artificial ligaments is not as “easy” as many doctors think, and the reconstruction of artificial ligaments must find the “isometric” point of the femoral and tibial tunnels to ensure that the ligaments remain tense during postoperative knee motion. Otherwise, the ligaments may become unstable due to the laxity of the ligaments at a certain angle. The above description will give you a general idea of the choice of ACL graft for those who are interested. For my patients, if they are athletes or have special needs, artificial ligaments are recommended; for the vast majority of the rest, the choice is between autologous or allogeneic grafts. For those who are torn between “autograft” or “allograft”, my opinion is that if you are “not bad off”, you should use allograft; if you are under financial pressure, you should use “autograft”. “There is no need to add extra burden to yourself.