Posterior cruciate ligament (PCL) injury

What is a posterior cruciate ligament (PCL) injury?

The PCL is the strongest ligament in the knee. It connects the bones of the upper and lower leg together and keeps the bones stable. The ligament can become sprained, pulled, torn or ruptured.

What are the different types of posterior cruciate ligament (PCL) injuries?

• Grade I – this mild injury can include a PCL sprain/pull, or tiny tears that can occur in part of the ligament (partial tear). The ligament may be stretched out of shape, but it can typically still hold the knee joint stable and support weight.

• Grade II – this moderate injury includes a partial tear; the knee is less stable and can give out while walking or standing.

• Grade III – this severe injury happens when the whole ligament is torn apart (complete tear); the ligament may come loose from the bone and the knee is unstable.

What are the signs and symptoms of posterior cruciate ligament (PCL) injury?

Symptoms will depend on the type and severity of the PCL injury including:

• Difficulty walking, especially going down the stairs

• Knee feels unstable and can give out

• Limping

• Pain that can worsen over time

• Stiff knees due to swelling

• Knee swelling that begins immediately after the injury

What are the causes of posterior cruciate ligament (PCL) injury?

PCL injuries are typically a result of a great trauma or force, which can include:

• Car accidents (hitting knee on the dashboard)

• Falling and landing on a bent knee

• A hard impact like incorrectly landing a jump

• A hit or sudden force on the front of the knee

• Kneecap dislocation

• Pulling or stretching the ligament

• Bending the knee too far backward during activities, such as sports or rough play