What Is PCL Injury?
The posterior cruciate ligament (PCL) is the strongest ligament in the knee. It extends from the top-rear surface of the tibia (bone between the knee and ankle) to the bottom-front surface of the femur (bone that extends from the pelvis to the knee). This ligament prevents the tibia from moving too much and going behind the femur.
A PCL injury (which may also be called hyperextended knee) is a partial or complete tearing or stretching of any part of the posterior cruciate ligament. The PCL is usually injured by overextending the knee (hyperextension). This can happen if you land awkwardly after jumping.
The PCL can also become injured from a direct blow to the flexed knee, such as falling hard on a bent knee.
Most PCL injuries occur with other ligament injuries and severe knee trauma. Often, the knee is dislocated and the nerves and blood vessels are injured.
If you suspect PCL injury, it is important to be seen by a doctor right away. PCL injuries often occur with other ligament injuries or severe knee trauma, so you should be checked early for these other conditions.
The symptoms of a PCL injury include:
- Knee swelling and tenderness in the space behind the knee (popliteal fossa)
- Knee joint instability
- Knee joint pain
Diagnosis of PCL Injury
If you or your doctor suspect a PCL injury, your health care provider will perform a physical examination to check for signs of PCL injury. Your doctor will begin by moving the knee joint in various directions.
Your doctor may also check if there is fluid in your knee joint. This test may show bleeding into the joint.
Other tests that may be ordered include:
- Knee MRI
- Knee joint x-ray
Treatment at Penn
PCL injuries require prompt first aid, including applying ice, splinting and elevating the joint. Once your PCL injury is considered stable, you should be evaluated by specialists who can create a personalized treatment plan for your injury.