The anterior cruciate ligament (ACL) consists of longitudinally arranged bundles of collagen fibers surrounded by synovial membrane. It is a ligament in the knee joint that connects from the posterior aspect of the femur (thigh) forward to the tibia (calf), and acts like a splicer between two column cars, allowing movement of the knee joint but restricting the tibia’s over-movement forward. In addition to its bonding role, the sensory nerve endings in the ligament play a role in maintaining the stability of the knee joint through a proprioceptive feedback mechanism. It consists of 2 bundles: the smaller anteromedial bundle and the larger posterolateral bundle, which primarily control forward hypermobility of the tibia and medial hyperrotation of the knee, respectively. With this action, the stability of the knee joint can be maintained even when there is a sudden change in direction during sports.ACL rupture not only leads to instability of the knee joint, which affects the function of sports, but also aggravates the damage to the joint by secondary damage to the major structures in the joint. Secondary damage to other structures in the joint begins to occur within 1 year after ACL injury, and 10 years after ACL rupture, the incidence of meniscus injury rises to more than 90%, and the incidence of articular cartilage injury rises to 80%, finally leading to secondary traumatic arthritis.