This was a question from a high school volleyball player whom I had as a patient a couple of years ago. She had injured her knee during a game and was trying to play through it. She had a grade 2- MCL strain so she was able to play but it was painful. I had her take a break from volleyball for a few weeks to allow the ligament to heal while working on hip and knee strengthening. She was able to return a month later with no pain. She was an easy patient. However not all medial collateral ligament (MCL) injuries are quite so simple.
The knee joint
The knee is the largest joint in the body. The knee is made up primarily by the tibiofemoral joint and patellofemoral joint. The tibiofemoral joint is what most of us think of as the knee. It is the joint made between the bottom of the femur (the thigh bone) and the top of the tibia (the larger lower leg bone). The patellofemoral joint is the joint made between the femur and the patella (the kneecap).
What are ligaments?
Every joint has ligaments. Their function is to control excessive motion of the joint. They are also a source of proprioception. Proprioception is knowing where you are in space. For the knee, this means that you would be able to determine the position of the knee without having to look at it. Ligaments are primarily made of collagen fibers and have very little elasticity. They are meant to add stability and are not flexible. You cannot stretch a ligament without damaging it.
The medial collateral ligament or MCL is located on the inside of the knee. The MCL runs from the end of the inner femur (the thigh bone) to the top of the inner tibia (the shin bone). Its primary function is to limit excessive valgus. This is when the knee bends inward toward the other knee.
What is a sprain? Is it different than a strain?
A sprain is a tear or injury to a ligament. Whereas a strain is a tear or injury to a muscle or tendon. When the MCL is injured, it is considered a sprain because the MCL is a ligament at the knee.
How does the MCL get injured?
A MCL injury is primarily a sports injury but can happen to anyone. The injury typically occurs when:
- The knee is hit on the other side and buckles inwardly.
- Getting “clipped” in football.
- Abruptly turning, twisting, or cutting
- MCL sprain is one of the most common injuries in skiing.
What are the symptoms of a MCL tear?
There are several symptoms associated with a MCL. These include:
- A “popping” sound might occur during the injury.
- Pain on the inside of the knee
- Pain and swelling in the knee
- Feelings of knee instability – the knee might buckle or give way
- Difficulty moving the knee – bending or straightening
- Difficulty walking or putting weight on the affected leg
How bad is the tear?
As with all sprains, there are grades to the severity of the injury. These grades include:
- Grade 1: This is the mildest strain. Less than 10% of the collagen fibers are torn. Walking will, most likely, not be affected. Some tenderness to the touch but no instability. Return to play can happen within 10-14 days.
- Grade 2: This is a partial tear of the MCL. It is more than 10% of fibers but it is not a complete tear. There is more pain and swelling in the knee. Walking will be affected and there could be feelings of knee instability. This grade can be further broken down to 2- or 2+ which means that the symptoms in this grade could be closer to grade 1 or grade 3. Return to play typically occurs in 2-4 weeks.
- Grade 3: This is a complete tear. There will be significant swelling and pain over the inside of the knee. The person will typically have difficulty bending the knee. Crutches will be needed to aid in walking. There will be significant knee instability. Symptoms can last for weeks. Return to play typically occurs in 5-7 weeks.
Special considerations
Isolated MCL injuries can and do occur, but they commonly happen with other injuries to the knee. The “unhappy triad” is concomitant injuries to the MCL, anterior cruciate ligament (ACL), and the medial meniscus. These three tend to sustain injuries together. However, the lateral collateral ligament (LCL), lateral meniscus, and posterior cruciate ligament (PCL) could also be involved. Bruising to the underlying bone might also occur with an MCL injury. All of these structures will need to be tested by the physician or physical therapist to rule out injury.
Will I need surgery?
Good news here! At least, if we are just talking about your MCL. The MCL is highly vascularized which means that it has a very good blood supply. This allows it to heal on its own, and the vast majority of people who sprain their MCL will not need surgery. Surgery could be considered if there was a high grade concomitant injury of another structure, such as the ACL. Surgery is also an option for those who have suffered multiple MCL sprains or are professional athletes.
Who should I see?
- Physical therapist – If the injury is mild, it will probably heal on its own within a week or two. However, moderate to severe strains take time and physical therapy is going to be needed. Physical therapists can aid in decreasing pain and swelling, increasing strength and flexibility, and returning to sport safely. It is important to have a physical therapist assist in determining when the person is appropriate to return to sport and provide direction in how to prevent the injury from reoccurring.
- Orthopedist – If a grade 3 tear is suspected or other structures are involved then the person would need to see an orthopedist. Imaging would be required to confirm the extent of the injury. The orthopedist would discuss options including surgical repair if applicable.
What can I do at home?
There are many things you can do at home to aid in your recovery. These include:
- Relative rest – It is important to prevent further injury to the knee while it is healing. If you are having pain with walking or bearing weight on the affected leg, then use crutches to help. If you are able to bear weight through the leg but are still unable to return to your sport, then practice relative rest. This means that you perform an alternate activity that will not affect the injury. For example, biking or swimming while you are unable to participate in your sport is an excellent way to maintain cardiovascular levels and strength. Having equal strength in both legs and no pain with inward stress on the knee is required before returning to sport or activity.
- Ice – This is very important right after the injury. Ice the knee with an ice pack several times a day right after the injury especially if there is a lot of swelling. Elevate the knee above the level of the heart while icing to decrease the swelling. This can be done by lying on a couch and propping the leg up on a few pillows. Ice for about 20 minutes. Place a thin barrier, like a pillowcase, between your skin and the ice pack. You can continue to ice even after the initial injury especially if there is still pain and swelling.
- Range of motion exercises – These are very important to perform after the initial injury. They are very simple exercises designed to increase mobility of the knee while preventing the knee from getting overly stiff while recovering. They should be performed several times a day during the initial recovery. See the video below for some range of motion exercises for the knee.
- Flexibility exercises – These exercises are focused mainly on stretching the hip flexors, quadriceps, hamstrings, and the calf muscles. These muscles surround the knee and will tighten up when there is an injury to the knee. Improving the flexibility of these muscles will aid in the mobility of the knee. See the video below for instructions on how to stretch these muscles. You will need a stretch strap, dog leash, yoga strap, or something similar.
- Strengthening exercises – There are a couple different phases of strengthening when rehabbing from a meniscus tear. These include weight bearing and non-weight bearing exercises. Weight bearing refers to putting weight through the joint. Examples of weight bearing include standing, running, walking – basically anything performed when standing on your feet. Non-weight bearing exercises are to be performed first to start strengthening the muscles with no impact through the knee joint. Once some healing has occurred and the person can walk/stand with little discomfort then it is time to progress to weight bearing exercises. All of these exercises will focus on strengthening muscles around the knee and hip, especially the quadriceps. The quadriceps is the large muscle in the front of the thigh. When there is an injury to the knee it tends to shut down. This can lead to the feeling of the knee giving out. It is important to turn that muscle back on asap. Using resistance bands or ankle weights can add resistance and strength. See the video below for weight bearing and non-weight bearing exercises.
- Bracing – A brace or knee sleeve can be helpful in decreasing pain and swelling. It can also provide feelings of support and increase stability when returning to previous sports or recreational activities.
In review
- The medial collateral ligament or MCL is located on the inside of the knee.
- The MCL runs from the end of the inner femur (the thigh bone) to the top of the inner tibia (the shin bone).
- Its primary function is to limit excessive valgus.
- This is when the knee bends inward toward the other knee.
- MCL injuries are common in sports but can happen to anyone. An injury to the MCL occurs with:
- A force on the outside that causes the knee to buckle inwardly
- Abruptly twisting, cutting, or turning
- There are grades of injury, with grade 1 being mild and grade 3 being a complete tear.
- Symptoms include pain in the inner knee, swelling, difficulty weightbearing on the affected leg, and possible feelings of instability.
- Most MCL injuries will not require surgery but will need physical therapy.
- Isolated MCL injuries can and do occur, but they commonly happen with other injuries to the knee.
- There are things that you can do:
- Relative rest
- Ice
- Range of motion exercises
- Strengthening
- Bracing
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
Additional resources
https://www.physio-pedia.com/Medial_Collateral_Ligament_Injury_of_the_Knee