What is a posterior cruciate ligament injury (PCL)?
The cruciate ligaments are found in the middle of your knee joint, forming an “X” configuration as they cross each other to connect the thigh bone (femur) and the shin bone (tibia). The posterior cruciate ligament (PCL) is found at the back of the knee and prevents the tibia from sliding too far backwards.
The PCL is a thick, strong ligament requiring a powerful force to injure it. Therefore, it is not commonly injured in isolation. Injury mechanisms include landing on a bent knee, a direct blow to the front of the knee and over-straightening (hyperextension) of the knee. Unlike anterior cruciate ligament injuries, partial PCL tears are commonly seen. A complete PCL rupture is a serious injury often associated with damage to other structures.
What are the symptoms of PCL injury?
At the time of PCL injury, there is deep pain and rapid onset of swelling make it very difficult to walk. Once the pain and swelling have resolved your knee can feel unstable and may give way. Sometimes the symptoms are quite subtle, particularly with partial tears
How is a PCL injury diagnosed?
The symptoms and a careful examination will usually suggest the diagnosis. An x-ray can be useful, but an MRI scan is the investigation of choice.
How is it treated?
Fortunately, most people with isolated PCL injuries don’t have knee surgical intervention. Injuries heal well and individuals can eventually return to sports without problems. Initial treatment is aimed at managing the pain and swelling through rest, analgesic/anti-inflammatory medication, ice therapy and crutches may be used to help mobility. A special knee brace, designed specifically for PCL injuries, helps prevent further instability and restores the relationship between the tibia and femur to promote PCL healing. As the pain and swelling subside, specific rehabilitation is started to restore motion, function and strength to your knee and leg.
Surgery is recommended in severe injuries involving multiple knee ligaments including the PCL. The torn ligament is replaced with a tissue graft. This can be taken from another part of your knee or leg (autograft) or from a human cadaver donor (allograft). In the case of multiple ligament injuries, a combination of both is often required. The advantages and disadvantages of each option will be discussed by the surgeon to choose the best graft options for each individual. It can take several months for the graft to heal to your bone.
Physiotherapy and rehabilitation play a crucial role whether you have surgery or not. Full recovery can take up to a year, and sometimes longer with multiple ligament injuries. Although at times you may feel frustrated, commitment to therapy is the most important factor in getting back to the activities you enjoy.