Medial Ligament Sprain
The medial collateral ligament (MCL) is the most commonly injured ligament of the knee. MCL injury is common among sportspersons and people who are physically active.
Ligaments are strong fibrous cords that hold the bones together in a joint providing functional stability. At the knee joint, multiple ligaments connect the thigh bone and the lower leg bones together. The medial ligament is one of a pair of external ligaments that extend from the lower end of the femur to the upper end of the tibia. It is also known as the tibial collateral ligament. Along with its counterpart, the lateral collateral ligament, it provides sideways stability to the knee joint.
It is present in close association with the joint capsule and is also attached to the medial meniscus – a fibrocartilagenous pad, acting as a cushion between the two bone ends.
A sprain refers to an injury to a ligament. It may be classified according to intensity:
Grade I: excessive stretching of the ligament resulting in tearing of a few fibres; however the ligament preserves its functional integrity; the joint is completely stable
Grade II: more severe damage, tearing of most of the fibres resulting in laxity of the ligament, the joint becomes relatively unstable.
Grade III: complete rupture of the ligament resulting in joint instability.
The cause may be a sudden traumatic incident such as a sports injury or a fall (especially in the elderly) or the ligament may become weak due to excessive overuse and may give way over time.
A sudden, forced inward bending of the knee would result in excessive stretching and consequently tearing of the medial collateral ligament.
As this ligament is in close association with the joint capsule and the medial meniscus, these structures are often involved as well. In athletes, usually such an injury results in damage to three structures; the medial collateral ligament, medial meniscus and anterior cruciate ligament (the unhappy triad).
Unhappy triad: damaged MCL, ACL and medial meniscus
An excessive outward rotation of the knee can damage both medial and lateral collateral ligaments.
- Pain is the most common symptom.
- Pain is felt on the inner side of the knee.
- The person may be able to walk after the trauma.
- Swelling is present in more severe injuries.
- Joint instability is also present if the damage is severe.
Diagnosis is usually based on the history of the trauma and on clinical examination.
X-rays are advised to rule out any associated bone fractures.
MRI gives a clear view of the extent of damage to the ligament and other associated structures.
In the acute phase follow the RICE protocol. Rest, avoid any painful activity, and use crutches to keep the load off the joint. Apply ice and compression to the area and elevate the injured leg. This helps to reduce pain and swelling. NSAIDs further help limit the pain.
For mild to moderate (Grade I & II) tears, conservative therapy usually works well.
- Continue with the rest
- Support the knee using a hinged knee brace
- Use ultrasound or manual massage to accelerate healing
- Use a heat retainer
Surgery is rarely indicated for medial collateral ligament injuries. However, if symptoms do not improve with supportive therapy, a meniscus tear or cruciate ligament tear may be present, for which surgery may be required. Surgery involves stitching the torn ligament. In some cases, a nearby tendon such as the hamstrings tendon may be grafted to repair the damaged ligament.
Rehabilitation should start early in MCL injuries. Following a comprehensive rehabilitation program serves to:
Speed up recovery
Improve movement at the joint
Strengthen the leg muscles to reduce load on the ligaments
Restore normal function
Return to activity should be very smooth and gradual. Start with mild flexion and extension of the knee. Initially keep the movement passive; use a towel or band to pull the ankle. Later on, bend the knee in the standing position or, placing the foot on a bench, push forward with your body, flexing the knee.
Stretching should be gradual and pain free. Hold each stretch for about 20 seconds or more if it doesn’t hurt. An undue stress may complicate healing. Be slow and consistent.
When movement becomes pain free, muscle strengthening exercises can be started. Begin with static contractions and increase the difficulty level as the pain allows. Stronger leg muscles help to stabilise the knee, sharing the work load on the ligament.
Massage improves the drainage of the area, helping the body to remove the excess fluid (thus decreasing swelling) and increasing blood flow to supply nutrients. Cross friction massage is especially recommended for ligament healing.
Once you are completely pain free and feel strong enough, you can start with more sports-specific exercises.