The posterior cruciate ligament is a strong ligament in the knee that corresponds to the anterior cruciate ligament. It is slightly thicker in diameter and longer than the anterior cruciate ligament and is twice as strong. Therefore, the posterior cruciate ligament plays an important role in stabilizing the knee joint. Because of the strength of the posterior cruciate ligament, the mechanism of injury to the posterior cruciate ligament is very different from that of the anterior cruciate ligament. ACL injuries are generally common in sports injuries, whereas posterior cruciate ligament injuries are mostly high-energy injuries such as traffic accidents, falls from height, and smash injuries. Because of the high energy injuries, posterior cruciate ligament injuries are often combined with posterior lateral complex injuries (to be described later) and joint capsule injuries. Severe posterior cruciate ligament injuries, especially combined with posterior lateral complex injuries, must be treated promptly and effectively, otherwise the knee will be in a significant posterior dislocation or subluxation, which can have a significantly greater impact on knee function than anterior cruciate ligament injuries. However, for a few patients with mild simple posterior cruciate ligament injuries, especially those with very mild posterior subluxation of the knee, surgery can be withheld for observation and active muscle strength exercises for the affected limb during this period. Treatment of posterior cruciate ligament injuries, like anterior cruciate ligaments, requires ligament reconstruction, and suturing the severed ends of the ligaments together is a very difficult and ineffective move. The principles and materials used in posterior cruciate ligament reconstruction are similar to those of the ACL, but differ significantly in individual points. In general, posterior cruciate ligament reconstruction is a more complex, demanding, costly and risky procedure than ACL reconstruction.