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MCL Sprain - Medial Collateral Ligament Injury

Updated: Apr 27, 2022

Medial Collateral Ligament Sprain:

Your medial collateral ligament (MCL) is the knee ligament on the medial (inner) side of your knee connecting the medial femoral condyle and the medial tibial condyle. It is one of four major knee ligaments that help to stabilise the knee joint. It is a flat band of tough fibrous connective tissue composed of long, stringy collagen molecules. The primary function of the MCL is to resist valgus force, which occurs if the tibia/foot is forced outwards to the knee.

What Causes MCL Sprain?

The MCL is injured when the (valgus) force is too high for the ligament to resist and the ligament overstretches. This overstretch can occur through a sharp change in direction, twisting the knee with a planted foot, landing wrong from a jump, or the most common a blunt trauma to the knee, such as a tackle in football. The incident commonly needs to happen at speed. Muscle weakness or incoordination could predispose you to a ligament sprain or tear.

How Serious Can A Sprained MCL Be?

In a mild, Grade I MCL sprain, the knee ligament has a slight stretch, but they don’t tear. Although the knee joint may not hurt or swell very much, a mild ligament sprain can increase a repeat injury risk.

With a moderate Grade II MCL sprain, the knee ligament tears partially. Knee swelling and bruising are common, and knee joint use is usually painful and challenging. You may have some complaints of instability or a feeling of the knee giving way.

With a severe Grade III MCL sprain, the ligament tears completely, causing swelling and sometimes bleeding under the skin. As a result, the joint is unstable and can be difficult to bear weight. You may have a feeling of the knee giving way. Often there will be no pain or severe pain that subsides quickly following a grade 3 tear as all of the pain fibres are torn at the time of injury. Other structures are at risk of injury with these more severe tears, including the meniscus or ACL.

What Does an MCL Sprain Feel Like?

There will be tenderness over the ligament site, possible swelling and pain with knee ligament stress tests.

How is an MCL Injury Diagnosed?

On examination, your physiotherapist will look for signs of ligament injury. They will also perform MCL stress tests. MRI may also diagnose a knee ligament injury and look at other surrounding structures for combination injuries.

What is the Treatment for an MCL Injury?

Depending on the grade of injury, you can start to feel better within days to just a few weeks of the damage. Your physiotherapy treatment will aim to:

  1. Reduce pain and inflammation.

  2. Normalise joint range of motion.

  3. Strengthen your knee: esp quadriceps (esp VMO) and hamstrings.

  4. Strengthen your lower limb: calves, hip and pelvis muscles.

  5. Improve patellofemoral (knee cap) alignment

  6. Normalise your muscle lengths

  7. Improve your proprioception, agility and balance

  8. Improve your technique and function, e.g. walking, running, squatting, hopping and landing.

  9. Guide return to sports activities and exercises

  10. Minimise your chance of re-injury.

However, we strongly suggest that you discuss your knee injury after a thorough examination from a knee injury specialist such as a sports physiotherapist, sports physician or knee surgeon.

How Long Does It Take To Recover From A Sprained MCL?

Treatment of an MCL injury varies depending on its severity and whether there are other combination injuries.

Grade I sprains usually heal within a few weeks. Maximal ligament strength will occur after six weeks when the collagen fibres have matured. Resting from painful activity, icing the injury, and some anti-inflammatory medications are useful. Physiotherapy will help to hasten the healing process via electrical modalities, massage, strengthening and joint exercises to guide the direction that the ligament fibres heal. This ligament healing helps to prevent a future tear.

When a Grade II sprain occurs, use of a weight-bearing brace or some supportive taping is commonplace in early treatment. This support helps to ease the pain and avoid stretching of the healing ligament. After a grade II injury, you can usually return to activity once the joint is stable, and you are no longer having pain. Ligament recovery may take a minimum of six weeks. Physiotherapy helps to hasten the healing process via electrical modalities, massage, strengthening and joint exercises to guide the direction that the ligament fibres heal. Ligament healing helps to prevent a future tear and quickly return you to your pre-injury status.

When a Grade III injury occurs, you usually wear a hinged knee brace, locked into extension, and use crutches for 1-2 weeks to protect the damage from weight-bearing stresses. As pain resolves, your knee brace can be unlocked to allow movement as tolerated. The aim is to allow for ligament healing and gradually return to normal activities. These injuries are most successfully treated via physiotherapy and may not return to their full level of activity for 3 to 4 months. All Grade III injuries rehabilitate under the guidance of your physiotherapist and knee specialist.


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