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).
The ligament prevents the knee joint from posterior instability. This means it prevents the tibia from moving too much and going behind the femur.
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 smashing your knee in a car accident (called "dashboard injury") or 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.
Knee swelling and tenderness in the space behind the knee (popliteal fossa)
Elevating the joint (above the level of the heart)
Taking nonsteroidal anti-inflammatory drugs (NSAIDs) for pain
Limit physical activity until the swelling is down, motion is normal, and the pain is gone. Physical therapy can help you regain joint and leg strength. If the injury happens suddenly (acute) or you have a high activity level, you may need surgery. This may be either knee arthroscopy or open surgical reconstruction.
Age has an effect on treatment. Younger patients are more likely to have problems without surgery, because chronic instability may lead to arthritis symptoms many years later. Many people do well without surgery. Injuries in which the bone is pulled off with the ligament, or multiple ligaments are injured need to be repaired with surgery.
When to Contact a Medical Professional
Call your health care provider if:
You have symptoms of PCL injury
You are being treated for PCL injury and instability in your knee worsens
Pain or swelling return after they went away
Your injury does not appear to be getting better with time
You re-injure your knee
You have loss of sensation and decreased circulation in your foot
PCL injuries often occur with other ligament injuries or severe knee trauma. You should be checked early for these other conditions.
Use proper techniques when playing sports or exercising. Many cases are accidents and are not preventable.
Honkamp NJ, Ranawat AS, Harner CD. Knee: Posterior cruciate ligament injuries in the adult. In: DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez’s Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Elsevier Saunders; 2009:chap 23, section E.
Honkamp NJ, Ranawat AS, Harner CD. Knee: Posterior cruciate ligament injuries in the child. In: DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez’s Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Elsevier Saunders; 2009:chap 23, section E.
C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.