Posterior Cruciate Ligament (PCL) Tear
The posterior cruciate ligament (PCL) crosses inside of the knee joint with the anterior cruciate ligament (ACL), connecting the thighbone to the leg. Ligaments are strong non-elastic fibers that connect your bones together. PCL tears are not as common as ACL tears, but can result from certain twisting movements, falls, or direct contact to the knee or shinbone during contact sports. Some PCL tears are treated with nonsurgical methods. However, if other knee structures are injured as well, arthroscopic surgery is used to restore knee strength, stability, and motion.
The knee is structurally complex. It is composed of three bones. The thighbone (femur), sits on the larger leg bone (tibia). The kneecap (patella) glides in a groove on the end of the femur.
Large muscle groups in the thigh give the knee joint strength and stability. The quadriceps muscles are a large group of muscles on the front of the thigh that straighten and rotate the leg. The hamstring muscles are located at the back of the thigh. The hamstring muscles bend or flex the knee.
Four ligaments connect the knee bones together. Ligaments are strong tissues that provide stability and allow motion. The ligaments enable the knee to have the flexibility to move in various directions while maintaining stability.
The anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) cross inside of the knee joint. The ACL and PCL help to keep the joint aligned. The ACL and PCL counteract excessive forward and backward forces and prohibit displacement of the bones. The ACL and PCL control rotation of the tibia. You rotate your tibia when you turn your leg outward to push off the ground with the foot. For example, you use this motion to push off from the side to skate, run, or move your body to get into a car seat.
The medial collateral ligament is located on the inner side of the knee. The lateral collateral ligament is at the outer side of the knee. The medial collateral ligament and the lateral collateral ligament help the knee joint resist side to side stress and maintain position.
PCL injuries take place if the shinbone is impacted by force just below the knee or on the side of the knee while the leg is twisted, bending the knee more than its normal range, or from falling on a flexed knee with the toe pointed. PCL injuries can occur during contact sports, such as football or soccer. They can also result from car crashes.
Because initial symptoms can be vague, some people may not know that they have a posterior cruciate ligament injury until the pain worsens over time and the knee feels unstable. PCL tears can cause:
• Knee pain ranging from mild to moderate
• Rapid knee swelling and; tenderness
• Pain while kneeling, squatting, running, slowing down, or walking stairs or ramps
• Limping or problems walking
• Knee instability, a feeling that the knee is "giving out"
If you suspect that you have a posterior cruciate ligament tear, you should go to your doctor or an emergency department. A doctor can evaluate your knee for a PCL injury by reviewing your history, examining your knee, and reviewing medical images. Your doctor will ask about your symptoms and the circumstances of your injury.
Your doctor will order X-Rays to see the condition of the bones in your knee and to identify fractures. It is not uncommon for bone or cartilage to be injured with the ligaments in a knee injury. Commonly magnetic imaging (MRI) scans are used to best see the ligament injury, and associated injuries.
Initially following a posterior cruciate ligament injury, you should treat your knee with rest, ice, gentle compression, and elevation (R.I.C.E. Method). You should rest your knee by not placing weight on it. You may use crutches to help you walk. Applying ice to your knee can help reduce pain and swelling. Apply ice to your knee immediately following injury and then comply with your doctor's icing schedule. Elevating your knee at a level above your heart can help reduce swelling.
Your doctor may recommend over-the-counter or prescription pain medication. In some cases, people with a PCL tear wear a knee brace to support the knee.
Physical therapy rehabilitation begins as the swelling diminishes. A physical therapist will show you specific exercises to strengthen the quadriceps muscles and other muscles that support the knee joint. The goal of physical therapy is to strengthen the knee and restore function.
Surgery is almost always necessary for people with posterior cruciate ligament occurring with other types of knee injuries, such as cartilage or other ligament tears. Your orthopedic surgeon may recommend that you participate in physical therapy prior to surgery to ensure that the muscles surrounding your knee are strong. PCL surgery is usually an outpatient procedure. The goal of PCL repair surgery is to restore the function of the PCL to maintain the knees mobility, stability, and function, while preventing further injury.
During PCL surgery, the damaged PCL is removed and replaced with a healthy ligament, a graft. There are a few options for acquiring grafts. Grafts may be taken from another part of the body or from a donor cadaver. An orthopedic surgeon uses an arthroscope to perform surgery on a PCL tear.
An arthroscope is a very thin surgical instrument, about the size of a pencil. It contains a lens and lighting system that allows a surgeon to see inside a joint. The surgeon only needs to make small incisions and the joint does not have to be opened up fully. The arthroscope is attached to a miniature camera. The camera allows the orthopedic surgeon to view the magnified images on a video screen. Arthroscopic PCL repair is associated with less pain, reduced risk of infection, decreased swelling, and faster recovery times than open PCL surgery.
Surgically placed grafts may take several months to heal to the knee bones. Physical therapy rehabilitation follows PCL surgery to help decrease swelling, increase mobility and stability, and increase strength and knee function.