What is the posterior cruciate ligament (PCL)?
There are four primary ligaments in your knee that hold the bones together and keep your knee stable.
Two of these ligaments are known as the cruciate ligaments. The PCL is located in the back of the knee behind the ACL, and it connects the femur (thighbone) to the tibia (shin bone). The PCL keeps the tibia from moving too far backwards.
What can cause a PCL injury?
An injury to the PCL requires a powerful force, and an injury can happen following a hard blow to your shinbone just below the knee or if you fall on a bent knee. These types of injuries are common during:
- Motor vehicle accidents – A "dashboard injury" occurs when the passenger's bent knee forcefully hits the dashboard, pushing in the shinbone just below the knee
- Contact sports – Athletes in sports such as football and soccer can tear their PCL after a fall or tackle onto a bent knee
What are the symptoms of a PCL tear?
- Swelling and stiffness following the injury
- The knee feels unstable, like it may "give out"
- Pain at the back of the knee that feels worse when you kneel
- Pain in the front of the knee when you run or try to slow down
How is a PCL tear diagnosed?
If your physical examination suggests you have a PCL injury, Dr. Potts may order x-rays or an MRI to assess the severity of your injury and rule out further damage to other structures.
PCL injuries are classified according to a traditional grading system:
- Grade I – Partial tear of the PCL
- Grade II – Isolated, complete tear of the PCL
- Grade III – Tear of the PCL with other associated ligament injuries
What is the treatment?
For all grades of PCL sprains, initial treatment consists of conservative measures with rest, activity modification, bracing, and physical therapy. If your injury is severe or if there are additional torn ligaments, cartilage damage or a broken bone, Dr. Potts might recommend surgery to reconstruct the ligament. Surgery might also be considered if you have persistent episodes of knee instability despite appropriate physical therapy and strengthening. PCL surgery usually can be performed arthroscopically by inserting a fiber-optic camera and long, slender surgical tools through several small incisions around the knee.