What is the Posterior Cruciate Ligament?

Located at the back of the knee, the posterior cruciate ligament helps connect a bone in the lower portion of the leg with a bone in the upper portion. It helps accomplish this task along with the anterior cruciate ligament, and two lateral ligaments. An injury to the posterior cruciate ligament can often be very difficult to deal with, simply because of its importance in helping with mobility.

The two main bones that the posterior cruciate ligament helps connect are the tibia, the larger bone in the lower leg, and the femur, or thigh bone, located in the upper leg. Its main purpose is to make sure the tibia does not move back too far. If this does occur, it is known as a hyperextension, which can be a minor or major injury, depending on the degree of the hyperextension.

In most cases, the anterior cruciate ligament is often the one that receives the most damage, and is usually more of a concern with injuries. This is because the posterior cruciate ligament is the thicker of the two. Therefore, if one of the two ligaments gets strained to the tearing or breaking point, it is usually not the posterior ligament.

Like all ligaments, the posterior ligament is more pliable than bone, and is able to bend and stretch somewhat. There is a limit, however, to how far it can stretch. If there is a tear, the knee becomes very unstable, and the injured person is often in a substantial amount of pain. Therefore, those who tear the ligament usually know there is a serious problem immediately. It may take an MRI for a doctor to be certain of what the particular problem is.

When this injury takes place, repair may be done in surgery through posterior cruciate ligament reconstruction, or through less invasive procedures. Immobilization, such as a splint, and physical therapy are often recommended after the initial injury. If those do not work, surgery may be the only other option. Recovery from a posterior cruciate ligament tear can take as long as one year, especially if surgery is required.

For those who have posterior cruciate ligament reconstruction, the process is often more difficult than going in and sewing the ligament back together. In most cases, a graft from another ligament elsewhere in the body, or from someone else, will be needed in order to adequately repair the injury. Still, while this may require a few extra steps, a successful recovery is much more likely with this method than with others.