Anatomy of the Medial Collateral Ligmament
Todd Sabol MS, AT
The knee is the largest joint in the body, and due to the amount we ask our lower extremity to do during our daily activities, athletics and in the gym, it is very commonly injured. Over five million people will visit an orthopedic physician this year for knee related pain. As we talked about in our previous article outlining the anatomy of the knee, we know the knee joint is a modified synovial hinge joint, which mainly allows for flexion and extension. While the knee has a high range of motion (ROM), there are four major ligaments that we also previously outlined, and in this article we will discuss the Medial Collateral Ligament or MCL specifically. The MCL extends from the medial femur to the medial surface of the top of the tibia and this provides resistance against valgus forces, or when the knee is forced inwards (a common problem in ACL injuries). We commonly see injuries to the MCL when there is a high velocity force that causes valgus knee stress to the knee that it cannot withstand. This can be from a cutting motion, some type of a traumatic hit moving the knee medially, or another one I recently saw in a football game that is not very common, a high velocity hyperextension mechanism. The MCL many times when the knee experiences these kinds of forces will be injured with the Anterior Cruciate Ligament (ACL) and Medial Meniscus. When all three of these structures are injured at the same time, it is referred to as the “unhappy triad”.
When we, or a patient or athlete we are working with experiences an injury to the MCL we need to first establish what the mechanism of injury was, because this can make the diagnosis of the injury much easier. Next we need to get an evaluation of the ligament and the gauge instability of the joint itself, which then would be followed up with an x-ray and most likely an MRI. Once the severity or grade of the injury is identified then we can take the correct treatment steps. If it is a lower grade sprain (grade 1 or sometimes 2) we can differ to conservative treatment and rehab the knee and structures around it to regain the joint integrity and stability. If it is a grade 3 tear, then the surgical option would be the logical choice. Since the surgical option is not something I deal with in terms of the actual procedure, let’s talk about conservative treatment and rehab.
Initially we may need some time to let the MCL heal, which can take a little while but even in these beginning stages we can perform some low level ROM exercises to help regain full flexion and extension, keeping in mind we do not want to aggravate the injured tissue, so we want to make sure this is being done in a pain-free range. Once we have achieved pain free, full ROM, we can begin to address the tissue and musculature around it. When we think about the anatomy of the MCL, we know that inferior to the area that the MCL spans, there is a landmark called the pes anserine. This landmark is an attachment site for 3 large muscles, the sartorius, gracilis and semitendinosus. The sartorius and gracilis are hip adductors, which help bring the leg towards the body, and they help with hip flexion. The semitendinosus, which is one of the three hamstring tendons, assists in hip extension and knee flexion. So we want to focus on adding in these movements to strengthen the tissue around the MCL. We also want to make sure we are fully encompassing the lower extremity musculature of the knee so we really want to focus on the entire quad musculature, entire adductor complex and can even add some calf work in there as well. I am currently working with an athlete who had a lower grade MCL sprain and just after a few days of focusing on these things, we have made major progress.
If you have ever had an MCL injury, you know that the rehab is very important in regaining the stability of the knee and how you perform in your sport, in the gym or in daily life. I would highly recommend you focus on a lot of hip, hamstring, adductor and quad work to increase the stability of the knee. I would also recommend you add A TON of core work and balance/proprioception work, once you feel strength is adequate. Once you feel comfortable with your rehabilitation, you can begin to work into low level sport/activity specific things to see how you feel, but is important you work into this slowly so that you know your knee will be able to withstand it.
If you have any other questions or are having questions about MCL rehab or knee rehab in general please feel free to reach out and always remember to #HealByMoving.