A medial collateral ligament knee sprain (MCL sprain) commonly occurs when forces placed on the knee cause the medial ligaments to stretch too far resulting in a sprain or a tear.
There are two main causes of a MCL sprain:
- The first is from a direct force to the outside of the knee.
- The second is from twisting the knee.
A MCL knee sprain is very common in sports such as rugby or league where someone may tackle you form the side and cause your knee to fold inwards.
The twisting motion is very common in skiing of simply from slipping on a wet path. When working care must be taken to lift your feet when you are turning; twisting at the knee will increase the likelihood of a medial collateral ligament sprain. Occasionally repetitive strains have been known to aggravate the MCL common examples are; swimming breaststroke or working on a slippery floor.
As the deep fibres of the MCL attach into the medial meniscus it is quite common to see the medial meniscus damaged at the same time as the MCL. In really bad injuries such as a grade 3 rupture you may even see the anterior cruciate ligament being damaged as well. When the medial collateral ligament, the anterior cruciate ligament and the medial meniscus are all damaged it is known as the terrible triad and a lengthy recovery will ensue.
As with most injuries the worse your injury the worse your symptoms will be. Specific tests done by your physiotherapist will determine the diagnosis and degree of injury, guiding their rehabilitation plan.
Grade 1 sprain:
- Minor tenderness over the medial knee.
- Minimal swelling.
Grade 2 sprain:
- Significant tenderness over the medial knee.
- Moderate swelling.
- Minor instability of the knee.
Grade 3 complete tear:
- Pain is variable but will be rather uncomfortable to palpate over the medial knee.
- Swelling to the medial knee.
- Instability of the knee; it will feel wobbly and have no resistance to sideways movements (valgus stress).
The rehabilitation program will vary according to the degree of injury, in the case of a severe sprain a brace may be required.
The general rehabilitation protocol with consist of the below steps:
- RICED (rest, ice, Compression, elevation & diagnosis) is vitally important early on to help reduce swelling and allow the knee to recover.
- Initial treatment is focused on restoring movement to the knee, reducing swelling and any pain.
- Mobilisations and specific massage techniques are used to mobilise the joint and help strengthen the injured ligament.
- Strengthening and balance/proprioceptive rehabilitation.
- Sports or job specific rehabilitation.
- It is common to require taping or strapping for your return to sports to help prevent re injury.