Blogs Sports Injury

PCL Injury

The posterior cruciate ligament (PCL) is one of the important ligaments that maintain the stability of the knee joint.

Where is the PCL, and what does it do?

The PCL is located near the back of the knee joint. It connects the femur to the tibia and prevents excessive backward movement of the tibia under the femur.

The ACL is the main restraint to the forward movement of the tibia under the femur (anterior translation of the tibia). It is the first ligament that becomes tight when the knee is straightened.

How do PCL injuries occur?

The most common mechanism of PCL injury is a direct blow to the front of the knee when the knee is bent, eg. a dashboard injury.

The PCL can also be injured with other modes – eg. falling on a bent knee, violent hyperextension of the knee.

Articular cartilage

Articular cartilage is the white, smooth material that covers the ends of the bones of any joint. The articular cartilage is about 6mm thick in most large joints. It is white and shiny with a rubbery consistency. It is a slippery and allows the surfaces to slide against one another without damage to either surface.

The function of articular cartilage is to absorb shock and provide an extremely smooth surface to facilitate motion. Articular cartilage is essentially present in all joints that move. In the knee, articular cartilage covers the ends of the femur, the top of the tibia, and the back of the patella.

How are PCL injuries identified?

PCL injury doesn’t make the knee swell as much as the ACL injury

Patients may have stiffness and swelling, in addition to feeling of giving way of the knee. The pain and moderate swelling usually subsides in two to four weeks, but the unstable may remain.

How is a PCL injury diagnosed?

The history and physical examination are most important in diagnosing a ruptured PCL. The posterior Lachman test, the posterior sag test, and the posterior drawer test may help make the diagnosis. Tests are also done to see if other knee ligaments or joint cartilage have been injured. The posterolateral corner (PLC) can be injured along with the PCL. Such a combined injury can lead to rotatory instability.

Patients may have stiffness and swelling, in addition to feeling of giving way of the knee. The pain and moderate swelling usually subsides in two to four weeks, but the unstable may remain.

The magnetic resonance imaging (MRI) scan is the most accurate test to diagnose a PCL injury. Sometimes, arthroscopy may be used to make the definitive diagnosis if there is a question about what is causing the knee problem.

  • Pain and swelling immediately following the injury
  • Stiffness that may cause a limp
  • Instability or a feeling that the knee is “giving out”

How is PCL injury treated?

Nonsurgical Treatment

Initial treatment focuses on decreasing pain and swelling in the knee. Rest, ice, compression and elevation, along with a mild pain-killer can help decrease these symptoms. A long-leg brace and crutches will reduce pain and will help walk without a limp. Less severe PCL tears can usually be treated with a progressive rehabilitation program. Exercises help regain normal movements and improve the stability.

Surgery

If the PCL alone is injured, nonsurgical treatment may be sufficient. However, when the PCL is injured along with another ligament, eg. the PLC or the ACL, surgery to reconstruct the PCL is needed to improve the stability of the knee. Without reconstructive surgery, over time, knee instability and joint degeneration develop.

Surgery is preceded by physical therapy to achieve good knee movements and muscle strength. This practice reduces the chances of scarring inside the joint and can speed recovery after surgery.

Surgery is usually performed arthroscopically, with small incisions around the knee. Apiece of tendon or ligament is used to replace the torn PCL.

What should I do after the surgery?

Continuous passive motion (CPM) machine will help move the joint and avoid stiffness. You will have to wear a protective knee brace for up to six weeks after surgery, and use crutches for two to four weeks.

You will be involved in a progressive rehabilitation program for four to six months after surgery, with visits to the physical therapist once in few weeks, in order to ensure the best result from the PCL reconstruction surgery.