In this illustration, looking at the knee from the side, the joint has been cut in half to show the position of the posterior cruciate ligament.
Anatomy of the posterior cruciate ligament
The posterior cruciate ligament is one of two main ligaments in the centre of the knee, the other being the anterior cruciate ligament.
It reaches from the back of the upper end of the tibia bone to the roof of the notch in the femur at the front.
The posterior cruciate ligament is comprised of two "....functional bundles: the larger anterolateral bundle...and the smaller posteromedial bundle...." and "to have a grade III PCL injury, both bundles need to be torn...."
What is the function of the posterior cruciate ligament?
The posterior cruciate ligament prevents the femur sliding too far forward in relation to the tibia when the person walks or runs.
The anterior cruciate ligament (not shown) has an opposite function.
"....The posterior cruciate ligament (PCL) is the largest and strongest ligament in the human knee, and the primary posterior stabilizer...."
How is the posterior cruciate ligament injured?
A PCL injury may happen when any extreme forwards force is applied to the top of the tibia when the knee is bent.
"....Common causes include dashboard injuries where the knee is forced into the dashboard during a motor vehicular collision. The PCL also can be injured secondary to falling forward onto a flexed knee. The most common sports where PCL injuries occur are football, skiing, soccer, and baseball. Less commonly, damage can occur due to a rotational hyperextension injury to the knee joint....."
Management of posterior cruciate injuries
Not every torn posterior cruciate ligament is reconstructed.
Reconstruction is performed less often for posterior cruciate ligament tears than for anterior cruciate ones. The anatomy is more complex, although the associated instability tends to be less disabling.
Really, good restoration of function is the domain of the super-specialist. Surgeons need special expertise to reconstruct the posterior cruciate and also often need comparable expertise in the management of concurrent injuries of the posterolateral corner.
Forum discussions
- "PCL/PLC etc.. reconstruction - Am I really volunteering for this?" - Patients comparing notes about their PCL injuries.
- "range of motion issues" - Problems with rehab after PCL and posterolateral corner reconstruction.