In our previous blog posts, we discussed the anterior cruciate ligament and prevention of non – contact ACL injuries. We also briefly mentioned the Posterior Cruciate Ligament (PCL), Medial Collateral Ligament (MCL) and Lateral Collateral Ligament (LCL). Today’s blog post will focus on the Posterior Cruciate Ligament and rehabilitation after a PCL injury.
What does the PCL do?
The PCL is one of the two cruciate ligaments in the knee. The PCL is stronger and twice as thick as the ACL. The PCL acts as the major stabiliser of the knee and it's job is to stop the shin moving backwards in relation to the femur (thigh bone). It also helps to stop hyper extension of the knee and other non - favorable movements at the knee joint.
Posterior cruciate ligament (PCL) tears are not as common as anterior cruciate ligament (ACL) tears. They are rare as an isolated injury and more commonly occur alongside other ligamentous injuries. More severe PCL injuries (Grade III) will occur along with other injuries more commonly whereas lower grade injuries tend to occur as a standalone injury.
So how do PCL injuries occur?
There are many different mechanisms of injury to the PCL. Generally, the PCL is injured in a high – energy traumatic incident such as a sport or motor accident e.g. a direct blow to the front of the shin in a flexed knee. From an athlete’s point of view, the main mechanism is a fall in hyperflexion or an abrupt impact where the knee is hyperextended.
How are PCL injuries classified?
Grade I: The PCL has a partial tear.
Grade II: The ligament is partially torn and is looser than in Grade I.
Grade III: The ligament is completely torn and the knee becomes unstable.
Grade IV: The PCL is damaged along with another ligament in the knee
What treatment is advised for a PCL tear?
As a general rule, surgery is not advised for a PCL tear. Grade I and II PCL injuries are managed conservatively (rehab / non – surgical). Research shows very good outcomes and a high rate of return to sport for athletes who have sustained isolated grade I and II injuries and who have been managed non – surgically. For patients with a grade III PCL injury who have mild symptoms and low activity demands, there is no call for surgical management.
However, there is an increasing change of opinion towards surgical intervention regarding PCL injuries. Surgery may be recommended for a severe grade III PCL tear or a PCL injury that has other associated injuries. However, generally surgical management is reserved for high-demand athletes or patients in whom nonsurgical management has been unsuccessful.
What does PCL rehabilitation entail?
Patients who suffer a PCL injury will generally remark that their knee feels unstable. As we mentioned at the beginning of this blog, the PCL is the primary stabiliser of the knee, so that complaint makes sense.
The question becomes, how do we stabilise a joint that no longer has the structural support of it’s primary stabiliser? This is where a thorough rehabilitation programme comes in. The aim of rehabilitation is to enhance muscle strength to stop the shin from translating backward.
Immediately after a PCL injury, the goal is to avoid any backward translation of the shin bone to give the ligament the best chance to heal. From there, a progressive programme of knee range of motion and quad strengthening will begin. When the swelling / bruising has diminished, a more aggressive strength programme will be introduced to develop all the musculature around the knee. The main aim here is to stabilise the knee by strengthening the surrounding musculature.
After approx. 12 weeks of rehabilitation, your therapist will make a call on a return to running programme, followed by a progressive sport specific regime with a view to returning to sport.
Are there long-term effects of a PCL injury?
As we mentioned previously, most people who suffer a PCL injury will be able to return to their sport with conservative management. However, research has shown an increased rate of arthritis in the knee due to a change in how the knee moves and tolerates load.
If you have any questions, or if you have recently sustained a PCL injury, get in touch!
Thanks for reading,
Edel!
References:
Vaquero-Picado, A. and Rodríguez-Merchán, E.C., 2017. Isolated posterior cruciate ligament tears: an update of management. EFORT open reviews, 2(4), pp.89-96.
Wang, D., Graziano, J., Williams, R.J. and Jones, K.J., 2018. Nonoperative Treatment of PCL Injuries: Goals of Rehabilitation and the Natural History of Conservative Care. Current reviews in musculoskeletal medicine, 11(2), pp.290-297.
Bedi, A., Musahl, V. and Cowan, J.B., 2016. Management of posterior cruciate ligament injuries: an evidence-based review. JAAOS-Journal of the American Academy of Orthopaedic Surgeons, 24(5), pp.277-289.
Kambhampati, S.B., 2019. Posterior Cruciate Ligament Injuries of the Knee. EC Orthopaedics, 10, pp.56-60.
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