What is an MCL tear?
The medial collateral ligament (MCL) is a sturdy band of tissue on the inner side of the knee that connects the thighbone (femur) to the shinbone (tibia). The MCL, along with three other knee ligaments, provides stability and strength for the joint. A torn MCL usually happens from a blow to the outside of the knee. This can cause an injury to either the MCL or to the ligament stabilizing the outer side of the knee, called the lateral collateral ligament (LCL). A torn MCL is the most common knee ligament injury and can be either a partial or complete tear.
People who play contact sports or sports that involve quick turns and sudden stops have a higher risk of tearing their MCL. Swimmers can also tear their MCL as an overuse injury. Someone who has torn their MCL will notice pain and swelling in the knee after the injury.
Surgery is rarely needed to treat a torn MCL. Wearing a brace and applying ice to the injury, along with doing physical therapy exercises, will usually allow the ligament to heal completely.
What are the symptoms of an MCL tear?
When the MCL tear occurs, the person may hear a popping sound in the knee. After the injury, symptoms of a torn MCL can be mild or severe, depending on how badly the knee was hurt. There are three grades of MCL injuries.
Grade 1: Mild pain and tenderness in the knee indicates an MCL sprain.
Grade 2: Pain on the inside of the knee is more intense, and there might also be swelling. When the knee is moved by hand, the joint will be loose. These symptoms indicate a partially torn MCL.
Grade 3: The person will have severe pain and tenderness on the inside of the knee, and there will be swelling at the site of the injury. The joint will be noticeably unstable when manipulated by hand and could buckle under pressure. These are symptoms of a complete MCL tear.
Since MCL injury symptoms can be confused with symptoms of other medical conditions, your doctor may want to confirm an MCL tear with an X-ray, MRI or other test.
What causes an MCL tear?
MCL tears can occur from a sudden blow to the knee or from overuse of the ligament. Most commonly, a strong force against the outside of the knee causes the MCL injury as the knee bends inward toward the other knee. A fall in which you land with your leg splayed out can also can tear the MCL. Overuse of the MCL from repeated stress can stretch out the ligament and cause injury.
What are the risk factors for an MCL tear?
People with the highest risk of tearing their MCL are those who play contact sports or sports that are more likely to cause twisting of the knee by pivoting or stopping abruptly. Some of these sports include:
Swimming (due to leg kicks for the breaststroke or whip-kick technique)
It’s important to always wear appropriate safety equipment and use proper technique when participating in any type of sport or exercise. Regular physical exercise to strengthen muscles and bones may help prevent MCL injuries.
How is an MCL tear treated?
All grades of MCL injury can be treated without surgery. Rarely, the most severe grade 3 MCL tears might need surgical repair. Grade 1 and 2 MCL injuries usually heal within three weeks, but grade 3 tears might require six weeks or longer before the person can return to sports.
Rest is the starting point for nonsurgical MCL tear treatment. You may need to adjust your daily routine to avoid certain movements, such as squatting or kneeling, that could worsen the MCL tear. Other nonsurgical treatments include:
Nonsteroidal anti-inflammatory drugs will reduce pain and swelling in the knee.
Keeping the knee elevated decreases blood flow to the injured area and reduces swelling.
Apply ice to the MCL injury for about 20 minutes at a time several times a day. Wait at least an hour before icing the knee again. Crushed ice on the knee works best.
By wearing a brace on your knee, you can prevent another sideways movement that could make the injury worse. Some braces will allow your knee to move forward and backward, and others will completely immobilize the knee. Your doctor might also recommend using crutches for a few days to reduce stress on your knee.
Specific physical therapy exercises can strengthen your leg muscles and help restore your knee’s range of motion.
Surgery is rarely needed to treat a torn MCL, but there are cases when it is needed. The torn MCL might require reconstructive surgery if it is a grade 3 MCL tear that involves other knee ligament injuries, or if the knee joint continues to be unstable despite several weeks of nonsurgical treatment.
What are the potential complications of an MCL tear?
If the torn MCL occurred along with tears in one or more other knee ligaments, the joint may continue to be unstable even after treatment. Other complications include fractures, loss of motion and stiffness, and damage to nerves and blood vessels.
MCL reconstruction surgery comes with risks associated with any surgery, which include: