The medial collateral ligament (MCL) runs along the inner side of the knee and connects the thigh bone (femur) to the shinbone (tibia). This ligament allows the knee joint to move with stability while preventing side-to-side movement.
MCL injuries range from mild ligament sprains to partial tears and complete ruptures. A torn MCL can be painful, impair your ability to walk, and make it feel like you can’t hold your weight. MCL injuries are one of several common knee ligament injuries, including ACL tears and meniscus injuries. Unlike ACL injuries, which often require surgery, many MCL injuries heal successfully with nonsurgical treatment.
Symptoms of an MCL injury
The most noticeable MCL tear symptom is pain on the inside of your knee directly over the ligament. Other common symptoms include:
- Knee instability
- Knee stiffness
- Hearing or feeling a “pop” at the time of injury
- Bruising
- Swelling
- The inability to hold your weight on your injured leg
You should seek medical evaluation of your knee if any of these symptoms make it difficult to walk or bear weight. Call for an appointment with a Mass General Brigham Sports Medicine specialist or visit one of our convenient Orthopedics Walk In locations to have your injured knee evaluated immediately.
Grades of an MCL injury
MCL injuries are categorized based on the severity of the injury.
A grade 1 MCL injury is a mild sprain that can be caused by direct trauma to the knee, and is a common sports injury. In this type of tear, the knee remains stable but may feel painful and tender.
With a grade 2 MCL tear, the ligament is moderately damaged with a partial tear, and you might notice some instability. This type of injury is usually quite painful and accompanied by tenderness and swelling in the knee. Most grade 2 tears heal with nonsurgical treatment, though recovery may take several weeks.
A grade 3 tear is the most severe type of MCL injury, occurring when the ligament is completely torn. With a grade 3 tear, your knee will be unstable and painful. This type of tear can often accompany other damage to your knee, such as an ACL tear.
Causes and risk factors for MCL injuries
You are at a higher risk of a torn MCL if you play sports that are high-impact or involve lots of jumping, sprinting, and quickly changing directions, like football, soccer, tennis, and basketball.
Most MCL injuries occur when the outer knee is struck, forcing the knee inward and causing the ligament to stretch and tear.
How are MCL injuries diagnosed?
Your doctor will conduct a physical exam to determine your injury and the extent of the damage to the ligament. They may perform a valgus stress test to evaluate the stability of your knee. MCL injuries are often diagnosed from a physical exam alone, but your doctor may also complete the following tests to see how bad the sprain or tear is:
- X-rays, which can help rule out further damage such as a broken or fractured bone.
- Magnetic resonance imaging (MRI) or ultrasound, which generate images of the tissues in your knee to show ligament tears or damaged cartilage.
How are MCL injuries treated?
Most MCL injuries do not require surgery to make a full recovery unless other ligaments such as the ACL are also significantly damaged. Unlike the ACL, the MCL has a good blood supply, making it easier for the ligament to heal.
Depending on the severity of your injury, your MCL should be able to heal on its own with adequate time and care. Nonsurgical treatment options include:
- Resting
- Icing and elevating the injured knee to reduce swelling and pain
- Using crutches for extra support as you heal
- Wearing a knee brace to provide compression and extra stability
- Engaging in physical therapy exercises to regain strength and mobility in your knee
While most MCL injuries do not require surgery, your doctor may recommend a procedure for severe tears or injuries that include other structures in your knee. If you’re an athlete, your doctor may also recommend surgery to ensure the ligament can handle the ongoing pressure and stress of sports.
Depending on your injury grade, surgery involves either reattaching the torn MCL or reconstructing the ligament using a tissue graft.
Preventing MCL injuries
Strong leg muscles and proper training techniques can help reduce the risk of MCL injuries.
Other tips for avoiding MCL injuries include:
- Warming up and cooling down before and after exercise to prepare your body for strenuous activity and promote recovery
- Wearing proper footwear for better cushioning and support
- Using a knee brace during training to increase knee stability and reduce the chance of it buckling or bending incorrectly
MCL injury recovery time
The recovery time for an MCL injury depends on the severity of the ligament damage. The best way to recover from a torn or sprained MCL is to give your body adequate rest and avoid high-impact activity. Physical therapy focused on strengthening your knee and improving flexibility is especially vital for athletes that want to keep playing sports.
Recovery timelines vary by injury severity:
- Grade 1: about 3-4 weeks
- Grade 2: about 6-8 weeks
- Grade 3: up to 12 weeks or longer
Recovering from MCL surgery
Recovery from MCL surgery can take roughly 6-8 weeks. Typically, this procedure is performed on an outpatient basis, meaning your doctor may send you home the same day as your surgery to begin recovery.
To support your recovery, you will be given a knee brace and crutches to help protect the knee as it heals. You will meet with a physical therapist, who will recommend exercises that help you rebuild knee strength and flexibility.
FAQs
The ligament often makes a distinct popping sound or sensation during injury. Your knee will likely be painful, you may feel unstable, and walking will be difficult. The area will likely swell up and feel tender shortly after the injury.
You might be able to walk on a grade 1 tear, although it will likely be painful. Knee instability accompanies serious MCL injuries, making it difficult to put weight on your leg and hold yourself upright without the help of crutches.
Your knee will likely swell, bruise, and be tender after an MCL injury, making it difficult to bend your knee or do routine activities such as climb stairs or sit in a chair. Stiffness and pain are common symptoms of a torn MCL.
