A medial ligament sprain or MCL injury is a tear of the ligament on the inside of the knee, usually a result of twisting or direct impact. Here we explain the assessment and diagnosis as well as immediate first aid, treatment, rehabilitation, exercises, taping and advice from elite level sports physiotherapists.
MCL sprain symptoms
Medial knee ligament sprains are graded 1, 2 or 3 depend on the severity of the injury. Grade one is a mild sprain, grade two is moderate and grade three is a severe or complete tear of the ligament.
Grade 1 symptoms
For a grade 1 MCL injury, there may be mild tenderness on the inside of the knee but usually no swelling. The patient is likely to be able to walk or even run but not at 100% and they will likely be in some discomfort. When assessment tests which stress the ligament are applied there will be pain but no joint laxity (play valgus stress test video).
Grade 2 symptoms
Significant tenderness will be felt on the inside of the knee along the medial ligament and there is likely to be some swelling may be seen over the ligament. When the valgus stress test is applied there is a pain with mild to moderate laxity in the joint, although there is a definite end point as the ligament is not completely ruptured.
Grade 3 symptoms
This is a complete tear of the ligament, although pain can vary and is sometimes not as bad as that of a grade 2 MCL sprain. There is likely to be swelling although again this can vary as the joint capsule is often torn allowing fluid to escape. The patient may complain of having a very wobbly or unstable knee. Assessment tests will reveal significant joint laxity. A grade 3 injury is likely to occur with other joint damaging including an ACL sprain.
Read more on assessment and diagnosis for MCL sprains.
Causes & anatomy
The medial collateral ligament or MCL for short connects the thigh bone (or femur) to the shin bone (or tibia) on the inside of the knee and prevents the knee joint from moving sideways, particularly from forces on the outside of the knee.
The medial knee ligament itself has two parts to it; a deep inner section which attaches to the cartilage meniscus at the top of the shin bone, and a superficial band that originates higher up on the femur to an area lower down on the inner surface of the tibia.
Mechanism of injury
Medial ligament injuries are common in contact sports such as football and rugby, as well as martial arts. They can also occur in daily life through falls and twisting of the knee joint.
Injury to the MCL often occurs after an impact to the outside of the knee when the knee is slightly bent. The ligament on the inside of the knee becomes stretched and if the force is great enough, some or even all of the fibres will tear. A grade one tear consists of fewer than 10% of the fibres being torn. A grade 2 sprain is upwards of 10% but not a complete tear of the ligament as in a grade 3.
The deep part of the ligament is prone to becoming damaged first which may lead to a medial cartilage meniscus injury. Twisting the knee can also cause a medial ligament sprain as well as the possibility of an ACL tear. If the foot is planted and the player tries to turn quickly this can also lead to stressing the joint causing the inside of the joint to open and tear the ligament.
Gradual onset MCL sprains
Repetitive sideways forces on the knee (known as valgus forces) can gradually over time lead to an MCL sprain. For example from kicking a football with the inside of the foot or from kicking in martial arts. However, pain on the inside of the knee which does not occur after a sudden injury should also be considered for pes anserine tendinopathy or bursitis.
Treatment for medial ligament sprains
Treatment can be considered in terms of immediate first aid during the acute stage and longer-term rehabilitation which will depend on the severity of the injury. Sports Physiotherapist Neal Reynolds explains the treatment and rehabilitation process that elite footballers would undergo.
What can the athlete do?
Immediate first aid in the form of the PRICE principles (Rest, Ice, Compression, Elevation) should be applied as soon as possible. Apply ice or cold therapy wrap as soon as possible for 10 to 15 minutes and repeat every hour, reducing the frequency as symptoms allow. Ice should not be applied directly to the skin but use a wet tea towel or similar. Commercially available cold therapy knee wraps are convenient to use and will apply compression as well.
Rest from training or any activities or movements which are painful to allow healing to take place. Continuing to train or do any activity which causes pain will only prevent healing and prolong recovery.
Wear a compression bandage or knee support to help reduce any swelling and protect the joint. A hinged knee brace is best particularly for grade 2 and 3 injuries. It is a strong knee support which has solid metal supports down the sides to prevent sideways movement of the joint and protect the knee ligaments whilst healing. More severe grade 2 and full grade 3 injuries may require a limited motion hinged knee brace which also restricts the amount of movement or knee bend in the joint.
When pain allows a full rehabilitation programe of mobility, strengthening and finally functional exercises should be done to return to full fitness and prevent the injury returning. Seek professional medical advice if in any doubt, particularly for suspected grade 2 or 3 sprains.
Download our grade 1 MCL rehab program overview (PDF)
What can a professional therapist do?
A professional therapist will be able to do a full assessment to determine the severity of the injury and advise on treatment and rehabilitation. They also have a number of treatment options available:
Ultrasound treatment involves applying high-frequency sound waves to the injured tissues. A professional therapist may do this in the early more acute stages to help control swelling and pain. Interferential or tens involves applying electric currents to the tissue around the injury which can also help with pain and swelling.
Taping the knee joint can also provide a high level of support and protection. It can be done in the early stages as well as later on when returning to full training. A good taping technique can provide excellent support and often more support than some of the cheaper hinged knee braces, but the effectiveness of tape will reduce over time as the tape stretches slightly. It will need to be re-applied to maintain good support for the joint, particularly during competitive sport.
Play knee taping video
Manual therapy techniques including massage may be used as part of a rehabilitation program. Massage to the injured tissues should be avoided in the early acute stages. Later as the ligament starts to heel then light cross friction massage may be used and in particular, if there is a persistent pain in the later stages of rehabilitation then cross friction massage may be beneficial.
Do I need surgery?
Most medial ligament injuries do not require surgical treatment. If there is additional damage to the joint for example an ACL tear as well then surgery may be considered. However, it is thought there is no advantage even with grade 3 injuries to treating them surgically as opposed to bracing and rehabilitation exercises.
How long will it take to recover?
- A mild MCL injury or grade one sprain should take 3 to 6 weeks to make a full recovery.
- A more severe grade 2 or grade 3 injury may take 8 to 12 weeks.
MCL sprain exercises
A full rehabilitation program consisting of mobility and strengthening exercises should begin as soon as pain allows. Initially mobility exercises are done to restore full, pain-free range of movement. In the early stages, isometric strengthening exercises (static muscle contractions) can be done to help maintain muscle strength and prevent muscle wasting whilst the ligament heals.
As the ligament heals strengthening exercises such as mini squats, leg press, and step-ups can be done but movements involving a change of direction or sideways stresses should be avoided until much later in the rehabilitation program. A hinged knee brace should be worn to protect the ligament whilst exercising.
Read more on MCL exercises