The ligament is an important static stability factor of the knee joint, mainly functioning as a guide for limiting action. When the stress on the ligament exceeds its yield point, which is the landmark for complete rupture, it often results in a tear injury, which may still maintain the general continuity of shape, but its tension for maintaining joint stability is lost, leading to direct instability. If the violence is severe and there is a significant displacement of the knee joint, the continuity of the ligament shape may be lost, resulting in complete rupture, mostly manifested as complex instability. During the acute stage, the patient's knee joint may swell and ache, with protective muscle tension, and positive signs are difficult to detect, making early diagnosis challenging. In the late stage, patients often show varying degrees of knee instability, and unstable knees are prone to repeated injuries. The increased shearing stress on the meniscus and joint cartilage causes meniscus injury and exacerbates the degeneration of joint cartilage, leading to secondary traumatic arthritis. Although there are many late-stage ligament reconstruction methods, their long-term efficacy varies, and none can completely restore the anatomical and physiological functions of the original ligament. Therefore, early correct diagnosis and treatment are very important for knee ligament injuries.
