Posterior Cruciate Ligament Injury
PCL Injury
The knee is the most complex joint in your body and uses a delicately balanced system of bones, ligaments, and other structures to allow you to run, jump, perform cutting movements, and other advanced activities. The knee is made up of three bones: the femur (thigh bone), the tibia (shin bone), and the patella (kneecap). The two joints of the knee are the tibiofemoral joint (between the femur and tibia bones, this is the main knee joint) and the patellofemoral joint (between the kneecap and the trochlea, a groove on the front of the femur). The fibula bone is a thin bone on the outside of your lower leg that does not contribute to the knee joint, but is important to ankle stability.
Due to the geometry of the knee joint, it is inherently unstable and relies on ligaments, tendons, and other soft tissue (non-bony) structures for stability.
Ligaments: The knee ligaments support the knee through range of motion
Anterior cruciate ligament: This ligament is the most commonly discussed ligament, as it is commonly injured. It is located in the middle of the knee and runs from the back of the femur to the tibia. The ACL prevents the tibia from moving too far forward.
Posterior cruciate ligament: This ligament is also located in the middle of the knee and runs from the front of the femur to the back of the tibia. The PCL prevents the tibia from sliding too far backward.
Medial collateral ligament: This ligament is located along the inside of the knee and runs from a bony prominence on the inside of the femur to the inside of the tibia. It prevents the knee from collapsing inward.
Lateral collateral ligament: This ligament is located along the outside of the knee and runs from a bony prominence on the outside of the femur to the top of the fibula bone. This ligament works in concert with other soft tissue structures to prevent the knee from collapsing outward.
PCL injuries are less common than ACL injuries and occur when the knee sustains a direct blow to the front of the knee. This can occur in a motor vehicle collision with the dashboard or from a fall onto a flexed knee while playing sports. The PCL can also be injured if the knee is hyperextended. The majority of PCL injuries can be treated without surgery.
Education
Types of PCL Injuries
Ligaments are graded based on the amount of injury and looseness that is noted on physical examination. PCL injuries can occur in isolation or in combination with other ligament injuries (multi-ligament knee injuries). There are three types of PCL injuries:
Grade 1: Mild stretch or partial injury of the PCL, no change in knee stability
Grade 2: Partial tear of the PCL with a mild change in knee stability
Grade 3: Complete tear of the PCL leading to an unstable knee. These injuries are usually associated with other ligament injuries in the knee.
Symptoms & Diagnosis
Patients with a PCL tear with note swelling of the knee after the injury and may have pain to the outside or back of the knee. If patients try to resume activities, they may notice knee pain when changing speed while running or going down stairs. PCL injuries are diagnosed using physical examination and imaging studies to confirm the diagnosis. The physical examination is used to identify areas of pain, swelling, change in range of motion, and laxity (or looseness) of the knee. X-rays are used to look at the bones of the knee. MRI (magnetic resonance imaging) is an important part of the diagnosis and will allow evaluation of all the knee ligaments, meniscus, cartilage, and any other structures that may have been injured.
Treatment
PCL injuries can be treated with non-surgical or surgical means, however, the majority of PCL injuries improve without surgery. Non-surgical treatment options allow patients to return to sports between 2-8 weeks after injury, depending on severity, and include:
Rest and activity modification: All sports and active pursuits should be stopped until the knee inflammation resolves. Occasionally, patients require several weeks of crutch use to regain a normal gait.
Non-steroidal anti-inflammatory medications (NSAIDs) can help decrease inflammation
Brace: Use of a knee brace can help the patient feel more confident and secure when walking
Physical therapy: This is an important tool to help you strengthen and retrain the muscles of the knee to work better together. Physical therapy is critical to the non-surgical treatment of a PCL injury and involves early quadriceps strengthening exercises and regaining normal knee range of motion
Surgical treatment of PCL injuries is used in patients who have a severe PCL injury, PCL injuries in combination with other ligament injuries, or those who have tried a prolonged course of non-surgical treatment and continue to have pain or a sense that the knee is unstable. Patients are able to return to sports at 6-12 months after surgery.
PCL repair: This procedure uses stitches and anchors to hold the PCL in place to allow it to heal. It can only be performed in certain situations and injury patterns
PCL reconstruction: This procedure uses autograft or allograft tissue to reconstruct the PCL and secure it in place with stitches and metal buttons. Compared to ACL reconstruction, allograft tissue has been shown to be an excellent option for PCL reconstruction
Disclaimer: The information presented on this page has been prepared by Dr. Kew and should not be taken as direct medical advice, merely education material to enhance a patient’s understanding of specific medical conditions. Each patient’s diagnosis is unique to the patient and requires a detailed examination and a discussion with Dr. Kew about potential treatment options. If you have specific questions about symptoms you are having and would like to discuss with Dr. Kew, please click below to contact our office to schedule a visit. We hope the information above allows our patients to more thoroughly understand their diagnosis and expands the lines of communication between Dr. Kew and her patients.