Posterior Cruciate Ligament Ruptures
UW Health's Sports Medicine doctors in Madison, Wisconsin, treat a wide range of common athletic injuries, including ruptures of the posterior cruciate ligament (PCL) of the knee.
About the Posterior Cruciate Ligament (PCL)
The posterior cruciate ligament (PCL) is the strongest of the four major stabilizing ligaments in the knee. The PCL’s primary functions are to prevent relative forward (anterior) displacement of the femur (thigh bone) and backward (posterior) displacement of the tibia (larger leg bone below the knee) while also preventing hyperflexion of the knee.
Posterior Cruciate Ligament Injuries
The PCL can be injured in a number of ways, which most commonly occurs when landing on a knee (or both knees) with the knee flexed or in car accidents in which seat belts are not worn and the knee is hyper flexed or the lower leg forcefully contacts the dashboard.
- Dashboard injury: A backward force applied to the front of the lower leg just below the knee while the knee is flexed
- Severe hyperextension of the knee
- Forced hyperflexion of the knee
Injuries to the PCL are far less common than injuries to the anterior cruciate ligament (ACL). Because of this, treatment options and advancements for this type of injury have been slower to develop.
The PCL lies deep within the knee joint between the larger lower leg bone (tibia) and the thigh bone (femur). It crosses behind the ACL, which is also located in this area. The other two stabilizing ligaments, the medial collateral and lateral collateral ligaments, are located on the sides of the knee joint. The medial meniscus and lateral meniscus are two semicircular pieces of cartilage that sit between the femur and tibia and function as shock absorbers while also “deepening” the joint between the rounded surface of the femur and the flat surface of the tibia.
An athlete with a PCL injury experiences symptoms similar to most ligament injuries. Pain and swelling will usually resolve in two to four weeks if cared for appropriately. Unlike the ACL, the PCL is outside the joint capsule and subsequently may not fill the joint space with blood and swelling. Following the resolution of the initial symptoms, individuals may begin to notice a lack of stability in their injured knee. This most commonly occurs when the individual pivots or changes directions.
Symptoms of instability vary widely among those sustaining PCL injuries. Factors affecting knee instability usually depend on whether or not other injuries occurred. Individuals sustaining injuries to other ligaments or cartilage have less favorable outcomes.
Initial treatment focuses on relieving the swelling and pain associated with the injury. This is done with rest, ice, compression and elevation. Early immobilization may be necessary to avoid further injury.
Once the pain and swelling decrease, the second phase of treatment includes a therapy program to regain range of motion and strength. This is a progressive program that focuses on restoring normal knee movement and continues to emphasize strength and muscular control.
Individuals who can control swelling, pain and instability of their injured knee will not need surgery. It may however be necessary for these individuals to avoid high demand activities, such as soccer or football, for best results.
If instability, pain and swelling persist, surgery may be recommended. As with the ACL, the PCL is reconstructed by replacing the torn ligament with either the middle third of the patellar tendon or a portion of the hamstring tendon.
At the time of surgery, an arthroscope is used to inspect the knee joint and to repair or remove any meniscal damage. Tunnels are then made in the femur and tibia and a portion of bone on each end of the graft is placed at the end of each tunnel to fix the graft (which functions as the “new” PCL) in place at the location of the original PCL. The bone ends are then secured with screws.
After surgery, patients begin exercises for strength and range of motion (ROM). The rate of progression depends upon a variety of factors including: the extent of additional injuries, other surgery performed, wound healing rate, swelling, muscle tone and ROM. A removable knee brace that locks the knee in a fully extended position is worn for two to four weeks.
Initial rehabilitation includes exercises such as straight leg raises, quad sets and ROM exercises. Advanced strengthening exercises such as biking and swimming usually begin at around six to eight weeks after surgery, and light jogging at three to four months following surgery. A full return to high demand sports such as soccer, football, basketball or skiing may take six to nine months after surgery, depending on how quickly the rehabilitation progresses.
The physician, physical therapist and/or licensed athletic trainer will supervise your rehabilitation and work with you to increase your activity level safely. The goal of the surgery and rehabilitation is to eliminate instability of the knee, decrease the potential for cartilage injuries and safely return the individual to the highest level of activity possible.