Posterior cruciate ligament (PCL)
Posterior cruciate ligament (PCL), one of four major ligaments of the knee, is situated at the back of the knee. It connects the thighbone (femur) to the shinbone (tibia). The PCL limits the backward movement of the shinbone.
PCL injuries are very rare and difficult to detect when compared to other knee ligament injuries.
The posterior cruciate ligament is usually injured by a direct impact, such as a motor vehicle accident when the knee forcefully strikes against the dashboard or during sports participation when a twisting injury or overextension of the knee can also cause PCL injury.
Injuries to the PCL are graded based on the severity of injury. In grade I the ligament is mildly damaged and slightly stretched, but the knee joint is stable. In grade II there is a partial tear of the ligament. In grade III there is a complete tear of the ligament and the ligament is divided into two halves making the knee joint unstable.
Patients with PCL injuries usually experience knee pain and swelling immediately after the injury. This may also be associated with instability of the knee joint and knee stiffness that causes limping and difficulty walking.
Diagnosis of a PCL injury is made based on symptoms, medical history, and physical examination of the knee.
The doctor may order a few diagnostic tests such as X-rays and MRI scan. X-rays are useful to rule out avulsion fractures where the PCL tears off a piece of bone with it. An MRI scan is done for better visualization of the soft tissues.
In some cases, a repair of the ligament may be possible
Generally, surgery is considered in patients with a dislocated knee and multiple ligament injuries, including the PCL. Surgery involves reconstruction of the torn ligament using a tissue graft taken from another part of the body, or from a donor.
Surgery is usually carried out with the help of an arthroscope, using a few small incisions.
After surgery your knee will be placed into a special brace. Rehabilitation after a PCL injury is very important and it is imperative to follow postoperative instructions closely. You will discuss this in detail with Dr. Witty.
Risks and complications
Knee stiffness and residual instability are the most common complications associated with PCL reconstruction. The other possible complications include:
- Blood clots (Deep vein thrombosis)
- Nerve and blood vessel damage
- Failure of the graft
- Loosening of the graft
- Decreased range of motion