The posterior cruciate ligament (PCL) is one of the four major ligaments in the knee joint. The other three major ligaments are the anterior cruciate ligament (ACL), medial collateral ligament (MCL), and lateral collateral ligament (LCL)/posterolateral corner complex. The PCL is in the back of the knee joint and connects the back of the femur to the back of the tibia behind the ACL. Its primary function is to prevent posterior translation of the tibia on the femur but it also plays a role in the side-to-side stability of the knee.
The PCL is injured less commonly than the ACL. The most common mechanism of injury involves a blow to the front of the tibia (shin bone) with the knee bent. The PCL can also be ruptured in more violent injuries that lead to tearing of multiple ligaments in the knee.
The symptoms of a PCL injury are usually less dramatic than those of an ACL tear. Swelling is often only mild. The pain from a PCL injury usually resolves within 2-4 weeks. A sense of instability may persist, however, especially when changing directions.
Treatment for isolated PCL injuries initially focuses on rehabilitation and strengthening after the pain and swelling subsides. Partial tears of the PCL do not usually require surgical treatment; even isolated complete tears of the PCL do not always need to be surgically repaired.
If symptoms of instability persist after rehabilitation, surgical reconstruction of the PCL is recommended. As in ACL reconstruction, a new PCL is made by using tendon graft obtained either from the patient or from a cadaver (allograft). PCL reconstruction is typically performed as an outpatient procedure using minimally invasive arthroscopic techniques.