Heard about The Anterior Cruciate Ligament. What About The Posterior Cruciate Ligament?


posterior cruciate ligament (PCL)

Have you ever hit your knee against the dashboard of your car coming to an emergency stop? Or fallen onto the ground on the front of your knees resulting in your knees fully bent backwards? Chances are you might have a tear in a major ligament in your knee without you knowing. This ligament is the posterior cruciate ligament (PCL).

The posterior cruciate ligament or PCL is a lesser-known cousin of the anterior cruciate ligament (ACL) but of no less importance. It is one of the 4 key ligaments that stabilize your knee. Its primary functions are to prevent your tibia (shin bone) from sliding too far backwards, and providing rotational stability to your knee.

How Is The Posterior Cruciate Ligament Injured?

Some common ways the Posterior Cruciate Ligament may be injured:

  • Commonly known as the “dashboard injury”, it happens in car collisions where the shin hits the dashboard hard. The shin is forcefully pushed back. This happens when the knee is already in a bent position
  • Falling onto the front of the knee where the tibial tuberosity (top part of the shin bone which protrudes out) hits the ground first. This causes the shin bone to move backwards forcefully.
  • Forceful pressure on the front of the shin while the knee is hyperextended. (A player’s knee is extended out during the end of a kick in a soccer game. The player then receives a hard tackle from the front of the shin)

How Do I Know If I Have Injured My Posterior Cruciate Ligament ?

You may have torn your Posterior Cruciate Ligament. This is especially so if your knee is injured in the above few ways, The signs and symptoms for a Posterior Cruciate Ligament injury are similar to an ACL injury. These include swelling, pain, decreased mobility of the knee. The sensation of instability of the knee is, however, not as common and pronounced as an ACL injury. If you do have a sensation of instability, surgical intervention might be necessary. An example would be the knee giving way while turning or pivoting on it.

How Is It Diagnosed?

A major part of the diagnosis stems from you remembering as closely as possible how your injury occurred. A reliable test that your doctor or physiotherapist usually does is the posterior drawer test to test the integrity and laxity of the Posterior Cruciate Ligament. Further investigations such as X-Ray and MRI can help to confirm and assess the damage of the injury and reveal any other bony, ligament or cartilage injury.