Posterior cruciate ligament injury

Posterior cruciate ligament injury

Knee ​Condition

Posterior cruciate ligament injury

A posterior cruciate ligament injury (PCL) is a partial or total tear of the ligament in the back of your knee. Ligaments are strong tissues that connect bones. The PCL connects the tibia (shin bone) with the femur (thigh bone). The PCL prevents the tibia from moving excessively backward or forward and keeps the knee stable.


Bones are connected to other bones by ligaments. There are four primary ligaments in your knee. They act like strong ropes to hold the bones together and keep your knee stable.

Collateral ligaments. These are found on the sides of your knee. The medial collateral ligament is on the inside and the lateral collateral ligament is on the outside. They control the sideways motion of your knee and brace it against unusual movement.

Cruciate ligaments. These are found inside your knee joint. They cross each other to form an “X” with the anterior cruciate ligament in front and the posterior cruciate ligament in back. The cruciate ligaments control the back and forth motion of your knee.


Car accidents: PCL injuries are often caused by bumping a bent knee against the dashboard. This shock pushes the tibia through the part that is immediately below the knee and causes the PCL to tear.

Contact sports: PCL ruptures are frequently caused by falling on a bent knee and with the foot pointing down. The tibia is the one that hits the ground first and is therefore pushed back.

Other causes: PCL injuries can also be caused by the following factors:

  • Excessive bending of the knee
  • Excessive extension of the knee

Strong blows on the outer or inner side of the knee when the leg is twisting.


Unlike other ligament injuries, you will not hear a crack, snap or tear when you injure your PCL. You may not have any signs or symptoms, or you may have any of the following:

  • Sudden swelling or pain in the back of your knee.
  • Kneeling pain
  • Instability of the knee.
  • Pain when running or walking or when going up or down steps.

You may only need physical therapy and orthotic devices if your PCL injury is mild.

You may need surgery if you have a torn PCL or damage to other knee ligaments.