A posterior cruciate ligament injury is a partial or complete tearing or stretching of any part of the posterior cruciate ligament (PCL).

Your doctor will perform a physical examination to check for signs of PCL injury. This includes moving the knee joint in various ways (these manipulations are called a posterior drawer test and a quadriceps active drawer test).

Your doctor may also check for the presence of fluid in the knee joint (the ballottement test). This test may show joint bleeding (hemarthrosis).

PCL injury may be seen using the following tests:

• Knee MRI
• Knee joint x-ray

The posterior cruciate ligament (PCL) is a powerful ligament extending from the top-rear surface of the tibia to the bottom-front surface of the femur. The ligament prevents the knee joint from posterior instability -- that is, instability in the back of the joint.

The PCL is usually injured by hyperextension (overextending the knee), which 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 knee").

• Knee swelling and tenderness in the space behind the knee (popliteal fossa)
• Knee joint instability
• Knee joint pain

Initial treatment of a PCL injury includes splinting, applying ice to the area, elevating the joint (above the level of the heart), and 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 should be involved to help regain joint and leg strength. If the injury happens suddenly ( acute), or you have a high activity level, surgery may be necessary. 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, as reattachment can be more difficult.

Call your health care provider if symptoms of PCL injury occur.

Call your health care provider if you are being treated for PCL injury and you notice increased instability in your knee, if pain or swelling return after they initially subsided, or if your injury does not appear to be getting better with time.

Also call if you re-injure your knee.

Use proper techniques when playing sports or exercising. Many cases are not preventable.