What is a Posterior Cruciate Ligament Injury?

A posterior cruciate ligament injury refers to a strain or tear in the major stabilizing ligament in the back of the knee. The ligament is a thick band of tissue that stretches from the femur to the tibia and prevents the knee from moving too far backward. An injury is most likely to occur when sudden force is placed on the tibia, as can occur when a football player is hit in the lowered legs from the front. Minor strains and partial tears can usually be treated with painkillers, rest, and ice, though a large tear typically requires surgery.

Most knee injuries affect the anterior cruciate ligament rather than the posterior, as the anterior is much thinner and less protected. When a posterior cruciate ligament injury does occur, however, it is usually more debilitating. The posterior ligament is stretched whenever the lower leg is forced backward with the knee bent. Excessive pressure can be the result of a fall from height, a sudden stop or slip when running, or a direct blow to the front of the legs. Athletes who play contact sports and elderly people who suffer falls are at the greatest risk of a posterior cruciate ligament injury.

There may be an audible popping or tearing noise when a major posterior cruciate ligament injury occurs. The knee almost instantly becomes painful, tender, and swollen. The knee joint becomes unstable, and it may be impossible to bear weight on the leg. Less serious injuries may not be noticeable right away, and symptoms of pain and swelling often do not appear until several hours later. The knee might become difficult to bend and straighten fully following a minor posterior cruciate ligament injury.

Most relatively minor injuries can be treated at home, though it is still a good idea to visit a doctor whenever knee pain is present. A strain usually heals itself over the course of two to six weeks. An individual can reduce healing time by icing the joint, avoiding physical activity, and taking over-the-counter pain relievers. Once the knee starts feeling better, it is important to gradually return to exercise and wear a protective brace or wrap to prevent further damage.

Immediate medical attention is needed when a debilitating knee injury occurs. At the emergency room or doctor's office, a physician can take x-rays and magnetic resonance imaging scans of the joint to determine the extent of ligament damage. He or she might provide painkillers and a corticosteroid injection to relieve immediate symptoms. Arthroscopic surgery, which involves suturing or pinning ligament tissue back together, is usually needed following a major tear. Patients typically spend several months in physical therapy to rebuild strength before returning to normal activity levels.