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.