The posterior cruciate ligament (PCL) courses from the posterior intercondylar area of the tibia to the medial condyle of the femur. It gives dynamic stability to the knee by preventing posterior displacement of the tibia on the femur. The PCL is an extrasynovial structure composed of a large anterolateral portion and a small posteromedial portion.
The PCL resists 85-100% of posteriorly directed forces at 30º and 90º of knee flexion. The 2 bands of the PCL, the anterolateral band and the posteromedial band, have different tension patterns. The anterolateral band is under great tension during knee flexion, whereas the posteromedial band is under more tension during knee extension.
Related Medscape Reference topics:
MRI for Posterior Cruciate Ligament Injuries
Posterior Cruciate Ligament Injury [Sports Medicine]
Posterior Cruciate Ligament Pathology
Related Medscape resource:
Resource Center Joint Disorders