Posterior cruciate ligament injury

Posterior cruciate ligament injury happens far less often than does injury to the knee's better known counterpart, the anterior cruciate ligament (ACL). The posterior cruciate ligament and ACL help to hold your knee together. If either ligament is torn, you may experience pain, swelling and a feeling of instability.

Ligaments are strong bands of tissue that attach one bone to another. The cruciate (KROO-she-ate) ligaments connect the thighbone (femur) to the shinbone (tibia). The anterior and posterior cruciate ligaments form an "X" in the center of the knee.

While a posterior cruciate ligament injury generally causes less pain, disability and knee instability than does an ACL tear, it can still sideline you for several weeks or months.

Symptoms Causes Risk factors Complications

Signs and symptoms of a posterior cruciate ligament injury may include:

  • Pain. Mild to moderate pain in the knee can cause a slight limp or difficulty walking.
  • Swelling. Knee swelling occurs rapidly, within hours of the injury.
  • Instability. Your knee may feel loose, as if it's going to give way.

Signs and symptoms can be so mild that you might not even notice anything wrong. Over time, the pain may worsen and your knee may feel more unstable. If other parts of the knee have also been injured, your signs and symptoms will likely be more severe.

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