The anterior cruciate ligament is one of the most important stabilizing structures in the knee joint and is also the most susceptible to injury. ACL rupture is a common injury in competitive sports, especially in soccer, rugby and basketball. When a patient tells his doctor that he has had the misfortune of hearing an abnormal ringing sound while the knee is flexing and twisting, and that the knee is rapidly becoming painful and swollen, and that the swelling does not subside with a week of normal rest, then the patient’s ACL may be in jeopardy. For experienced knee surgeons, the combination of patient history and physical examination (the simplest of which includes the anterior drawer test and Lachman test) can be more than 90% accurate, even without imaging. For the average patient, although most physicians prefer to perform ACL reconstruction, there is still some controversy about how to choose the specific surgical details for middle-aged and elderly patients. AAOS released the latest guidelines in September this year, please listen to the author’s interpretation for you. The new guidelines, which provide guidance and recommendations for physicians’ clinical decisions, were completed under the authority of the American College of Sports Medicine, the American Academy of Orthopaedic Surgeons Sports Medicine Section, and the U.S. Department of Athletics. The most significant change from the previous guidelines is that they clearly state that for patients with an indication for surgery, ACL reconstruction is recommended within 5 months to avoid other injuries associated with knee instability. For patients with ACL injuries who regularly participate in sports activities, the later the reconstructive surgery, the higher the incidence of combined knee injuries, and the current evidence suggests that completing reconstructive surgery within 5 months may be a better time for surgery. At this point, the patient’s local symptoms have basically disappeared and he has undergone systematic and standardized non-surgical treatment. At this point, the patient is able to determine whether his knee joint can meet his daily life and sports, and thus decide whether he needs surgical treatment. Based on the author’s current clinical experience, other points that need to be kept in mind by the clinician are the following seven: 1. Detailed history taking and careful physical examination are the first elements. 2. MRI should be performed to clarify the diagnosis of ACL injury and to exclude the possibility of combined cartilage, meniscus and other ligament injuries. Recommendation level: Strong 3. For patients with epiphyseal unclosed ACL rupture, reconstructive surgery can be considered because of the reduced level of patient movement and other injuries induced by joint instability. Recommendation level: limited 4. For young active patients (18-35 years old), surgery is recommended. Recommendation grade: moderate 5. Combined meniscal injuries should be repaired during ACL reconstruction surgery. Recommendation grade: limited 6. In ACL reconstruction surgery, the choice of single or double bundle reconstruction, the choice of autologous or allogeneic tendon for the graft, and the choice of patellar tendon bone or N cord muscle for the autologous tendon cannot be proved by current evidence-based medical evidence, and should be decided jointly by the surgeon and the patient according to their own situation. Recommendation grade: Strong 7. In ACL reconstruction, whether the femoral tunnel should be used via the tibial tunnel technique or the medial approach technique, the current evidence-based medical evidence cannot prove which one is better. Recommendation grade: Moderate Please do not be confused by the recommendation grade, which here is proven by a large number of rigorous randomized controlled studies. While clinical decisions are based on guidelines, they are often more radical than guidelines, which are always conservative, and it is difficult to make progress in medicine by following them. As a newly initiated knee surgeon, combined with the current domestic situation, I believe that if you are a physician, as long as your surgical skills meet the standards, please boldly recommend early surgical reconstruction; the technique of ACL reconstruction in minors (patients whose epiphyses are still developing) is very different from that of adults, and it is recommended that specialists skilled in ACL reconstruction gradually carry out this technique, if your If your skills are not yet up to par, you can advise the patient to reduce sports or refer to an experienced physician for treatment. If your technique is not up to par, you can advise your patients to reduce sports or refer them to an experienced doctor. Other controversial issues can be dealt with according to your understanding of the disease and the patient’s requirements.