If you’re up on knee news, you probably hear a lot about tears to the anterior cruciate ligament (ACL). News about the posterior cruciate ligament (PCL) lags behind. PCL tears are less common and more difficult to treat. Some PCL tears may even go unnoticed because they don’t always produce symptoms.
PCL tears may be more common than previously thought. Researchers estimate that PCL injuries may make up 20 percent or more of all knee injuries. One researcher insists that PCL tears may account for as many as half of all knee injuries.
The PCL crosses behind the ACL. It is actually made up of two bands. These two bands work together to stabilize the knee when the lower leg moves backward or rotates outward.
PCL injuries happen when a force strikes the front of the bent knee. This can happen in a car accident when the knee hits the dashboard on impact. It can also happen in contact sports like football or wrestling. When the lower leg is struck by an opponent, the force can drive the shin backward, tearing the PCL. The PCL can also be torn when a player falls hard onto a flexed knee.
PCL injuries usually have fairly mild symptoms. Patients may have very little pain. And knee movement may be nearly the same as that of the uninjured knee. So it’s important that doctors do a thorough physical exam.
Most PCL tears can be treated without surgery. If the tear is not very serious, doctors typically recommend wearing a splint and using crutches for a short period of time. Thigh strengthening and range of movement exercises should follow. Recovery of strength and movement usually happens quickly. Patients may be able to return to sports as soon as four weeks after injury.
Studies have shown that this treatment (immobilization plus physical therapy) has good to excellent results for most patients. Patients can generally return to sports and other activities without limitation. However, in the case of more serious or chronic tears, surgery may be necessary. Surgery for the PCL is also called for if other knee ligaments are injured. In these cases, the PCL and other ligaments are surgically treated.
Typically, surgeons have used a “single tunnel” technique, in which they repair one of the bands of the PCL using grafts from the Achilles tendon. Newer “double tunnel” techniques allow surgeons to fix both bands of the PCL, which is believed to improve results. Another new procedure called “tibial inlay” involves entering the PCL through the back of the knee, to make the PCL easier to access. These newer techniques may be a step up from older methods. However, more research is needed to know which method consistently gives the best results.