The medial collateral ligament (MCL) is a thick band of tissue on the inner part of the knee, running from the thighbone (femur) to the shinbone (tibia). The main function of the MCL is to prevent the leg from overextending inward. It also stabilizes the knee joint and allows for smooth rotation during movement.

Along with anterior cruciate ligament (ACL) injuries, MCL injuries are among the most common knee injuries in athletes and active people.

MCL tears and sprains can cause significant knee pain and destabilization of the knee joint.

Many MCL injuries heal on their own with rest and rehabilitation, but some require surgery.

What Causes a Medial Collateral Ligament (MCL) Tear or Sprain?

The majority of MCL injuries occur when the outer side of the thigh or knee is hit with considerable force while the foot is on the ground. A blow to the outside of the knee or leg can cause the knee to collapse inward, placing intense stress on the MCL.

Contact sports like football and soccer produce a high number of MCL injuries due to regular collisions that target the legs and knees.

Regular wear and tear on the knee can also contribute to the weakening of the MCL, leading to a tear or sprain.

Medial collateral ligament sprains or tears often occur alongside damage to the meniscus or the anterior cruciate ligament. These multi-ligament injuries often cause significant pain, stiffness, and instability in the knee joint, and they require immediate medical attention.

What Are the Symptoms of a Medial Collateral Ligament (MCL) Injury?

The main symptoms of an MCL injury include:

1. A popping or snapping sound during initial injury
2. Immediate pain and swelling of the injured knee
3. A feeling of instability or looseness in the injured knee
4. A feeling of buckling or “giving out” in the injured knee during movement
5. Limited range of motion in the injured knee

The majority of MCL injuries cause some level of pain in the knee.

If you experience knee pain that is accompanied by stiffness, swelling, decreased range of motion or a feeling of instability in the knee joint, you should visit your doctor immediately.

Different Levels of MCL Injuries

Like ACL and PCL injuries, MCL injuries are categorized by grade:

Grade I – A Grade I MCL injury indicates a mild sprain or stretching of the ligament fibers. A Grade I MCL sprain may cause mild to moderate pain and slight swelling, but the knee joint remains stable.

Grade II – Grade II MCL injuries indicate a more severe sprain or stretching of the ligament. Pain and swelling may be more severe, and may cause noticeable instability in the knee joint.

Grade III – A Grade III MCL injury is a total rupture (complete tear) of the ligament. Pain and swelling are typically severe, and the knee joint is destabilized.

Grade III tears with concurrent meniscus or ACL injury may require surgical repair.

Treatment of MCL Injuries

Grade I MCL injuries are typically treated with a combination of rest, ice, compression, and elevation of the knee (the RICE method). NSAIDs (non-steroidal anti-inflammatory drugs) can help control pain and inflammation as a Grade I sprain heals. A knee brace may also help stabilize the knee during healing. Grade I sprains typically heal within a week or so.

Grade II MCL injuries can be treated using the RICE method. Knee pain can be managed using NSAIDs and wearing a brace during movement. Grade II injuries may require physical therapy if range of motion doesn’t adequately return. Because these injuries are more severe than Grade I sprains, they can take up to a month to heal.

Grade III MCL injuries that occur without damage to other structures in the knee may heal on their own with the RICE method and NSAIDs to control pain and swelling. Because these injuries are more severe, they can take up to two months to completely heal. Grade III MCL ruptures that occur alongside injury to other parts of the knee typically require surgical repair.

Surgery to repair the MCL will use tissue from your own body or a cadaver to surgically reconstruct the MCL.

Diagnosis and Treatment of MCL Injuries at Mobility Bone & Joint Institute

Mobility Bone & Joint Institute is the only practice in the Merrimack Valley that can diagnose diseases, infuse medications, and perform x-rays on site.

Do you have questions about the diagnosis and treatment of MCL injuries at Mobility Bone & Joint Institute?

Call (978) 794-1946 or click here to schedule an appointment at our Andover, MA office.

Call (603) 898-2220 or click here to schedule an appointment at our Salem, NH office.