Posterior cruciate ligament (PCL), one of four major ligaments of the knee is situated at the back of the knee. It connects the thighbone (femur) to the shinbone (tibia). The PCL limits the backward motion of the shinbone.
PCL injuries are very rare and are difficult to detect than other knee ligament injuries. Cartilage injuries, bone bruises, and ligament injuries often occur in combination with PCL injuries. Injuries to the PCL can be graded as I, II or III depending on the severity of injury. In grade I the ligament is mildly damaged and slightly stretched, but the knee joint is stable. In grade II there is partial tear of the ligament. In grade III there is complete tear of the ligament and the ligament is divided into two halves making the knee joint unstable.
The PCL is usually injured by a direct impact, such as in an automobile accident when the bent knee forcefully strikes the dashboard. In sports, it can occur when an athlete falls to the ground with a bent knee. Twisting injury or overextending the knee can cause the PCL to tear.
Patients with PCL injuries usually experience knee pain and swelling immediately after the injury. There may also be instability in the knee joint, knee stiffness that causes limping, and difficulty in walking.