Even though the posterior cruciate ligament (PCL) is one of the knee’s four major ligaments, it is the less well known relative of the anterior cruciate ligament (ACL). PCL tears aren’t as common as those in the ACL, and when they do happen, they usually are part of a wider injury.
Explore what happens in more depth and find out about the treatment options available at Sports Med London.
PCL – A Major Ligament
The PCL passes from the front, upper part of the thighbone (femur) just behind the kneecap (patella), through the knee joint, and connects to the back of the upper shinbone (tibia). The ligament’s main function is to stop the tibia from moving backwards.
How PCL Tears Happen
The most common cause of PCL tears and other injuries is a direct impact to the top of the tibia, such as by falling onto a bent knee or in a motor vehicle accident. Other causes include twisting injuries or forced over-straightening or extending the knee, which can happen when playing sports.
Symptoms of PCL injuries such as a tear include:
- Pain in the knee
- The knee feels stiff or unstable
- Difficulty walking
- Pain in the front of the knee or in the inner side of the knee when walking down stairs
Diagnosing And Treating PCL Tears
When diagnosing PCL tears, our specialist will ask you about the symptoms you’re experiencing and how the injury happened. They will then examine your knee physically.
If our specialist suspects you have an avulsion fracture, which is when the PCL tears off a piece of bone (which usually happens behind the shinbone), they will send you for x-rays and possibly an MRI scan.
If your PCL tear is partial or isolated, our specialist may recommend non-surgical treatment such as wearing a knee brace, resting, and doing physiotherapy exercises that emphasise developing your front thigh muscles (quadriceps).
If the PCL injury is part of a wider injury, such as an ACL injury or dislocated knee, our specialist may recommend surgical treatment. This can include performing a tissue graft to replace the torn ligament and securing it with special devices. If you also have an avulsion fracture, our specialist may repair it with a surgical screw.
After a period of recovery, you can begin a physiotherapy rehabilitation program aimed at helping you get back on your feet and return to the activities you enjoy. In most cases, patients can begin a phased return to playing contact sports approximately nine months after surgery. Keep reading to learn more about PCL tears.
What is the PCL?
The posterior cruciate ligament (PCL) is one of four major ligaments of the knee. It connects the back of the upper tibia (shinbone) and passes through the joint into the front and upper portion of the femur (thighbone) just behind the patella (kneecap). The PCL limits the backward movement of the tibia (shinbone).
What causes a PCL injury?
PCL injuries are rare and often associated with other injuries.
The posterior cruciate ligament is usually injured by direct impact against the top of the tibia (shinbone), such as fall onto a flexed (bent knee), a motor vehicle accident when the knee strikes against the dashboard or during sports when a twisting injury or forceful hyperextension (over straightening) of the knee occurs.
Patients with PCL injuries usually experience knee pain and swelling immediately after the injury. This may also be associated with instability of the knee joint and knee stiffness that causes limping and difficulty walking. Later they may present with anterior knee pain (pain in the front of the knee) typically with descending stairs or in the medial side (inner side ) of the knee.
How is a PCL injury diagnosed?
Diagnosis of a PCL injury can confidently be made on the presenting symptoms, mechanism of injury and physical examination of the knee. Xrays may be useful in determining if there is an avulsion fracture where the PCL pulls off a piece of bone typically from the back of the tibia (shinbone) . An MRI scan would confirm the soft tissue injury and allows visualisation of other injuries.
How is a PCL injury treated? Surgical vs Non-surgical management
Isolated PCL injures can be treated conservatively with physiotherapy with a particular emphasis on developing good quadriceps (front thigh muscles). Initial period following the injury is depending on the severity of the injury managed with a special PCL knee brace. This pushes the tibia forward preventing it from sagging backwards.
Surgery tends to be indicated for patients where a PCL injury is associated with other ligament injuries, such as with a dislocated knee, or in the case of isolated PCL injuries where conservative treatment has failed. This involves replacing the torn ligament with tissue either from another part of the body from the same patient (autograft) or from a donor (allograft) and passing it through bone tunnels in the tibia and femur and securing it with special mechanical devices. This is performed using an arthroscope via small incisions (keyhole surgery). If there is an avulsion fracture of the PCL this can be fixed often with a screw .
If combined with an ACL injury both ligaments are reconstructed by drilling bone tunnels and the passaged of grafts.
Following PCL reconstruction, a rehabilitation program with physiotherapy is started to help you to ultimately return to sport and a wider range of activities. Many patients are able to begin a phased return to contact sports by 9 months post-surgery. This is dictated by patients meeting milestones and under the supervision of the surgeon and specially trained physiotherapist.