The cruciate ligament of the knee, also known as the cruciate ligament, is located at the center and rear of the knee joint and is an important stabilizing structure of the knee joint. The cruciate ligament is lined by synovium and can be divided into front and back. When the knee joint moves, some fibers of the two ligaments are in tension. Therefore, the two ligaments cooperate to limit the hyperextension, flexion and rotation of the knee joint. The case shared in this article is the effect of