The medial collateral ligament (MCL) is the primary ligamentous stabilizer on the inside of the knee. MCL injuries are the most common knee ligament injury and typically occur from a direct blow to the outside of the knee or a valgus force during sport. Most MCL injuries heal with non-surgical treatment, but specific high-grade injuries and those associated with multi-ligament injury require surgical reconstruction.
What Is an MCL Injury?
The MCL is a broad ligament complex running from the medial epicondyle of the femur to the medial tibia. It has a superficial portion and a deep portion, and it resists valgus force (a force pushing the knee inward) and provides secondary restraint against external rotation. The MCL works with the cruciate ligaments and the posteromedial corner to stabilize the knee against forces that would displace the tibia relative to the femur.
MCL injuries are graded:
- Grade 1: microscopic stretching without loss of structural integrity, mild tenderness without laxity
- Grade 2: partial tear with some increased laxity but a firm endpoint on stress testing
- Grade 3: complete tear with significant laxity and no firm endpoint
Grade 1 and 2 injuries reliably heal with non-surgical treatment. Grade 3 isolated injuries also typically heal, though with longer recovery. Grade 3 injuries in combination with ACL or other ligament injury require more careful management.
Causes and Risk Factors
- Direct blow to the outside of the knee (football tackle, skiing collision)
- Valgus force with the foot planted (cutting injury in soccer or basketball)
- Twisting injuries with the knee in flexion
- Contact sports and skiing have the highest incidence
- Prior MCL injury increases the risk of recurrent injury
Symptoms
- Pain on the inside of the knee immediately after injury
- Swelling over the medial knee (often localized rather than the diffuse joint swelling of ACL injury)
- Feeling of the knee opening up on the inside with valgus stress
- Tenderness to palpation along the length of the MCL, from the medial epicondyle to the proximal tibia
- Difficulty with cutting and pivoting in higher-grade injuries
Diagnosis
Dr. Chudik’s evaluation includes the mechanism, the specific position of the knee at the time of injury, and a physical examination with valgus stress testing at 0 degrees (tests the MCL and associated posteromedial structures) and 30 degrees (isolates the MCL). Associated ligament testing is always performed, particularly for ACL injury. X-rays rule out associated fractures. MRI confirms the grade, location, and any associated injuries. The Westmont office has on-site high-field MRI and X-ray.
Treatment
Non-surgical treatment is appropriate for isolated grade 1, 2, and most grade 3 MCL injuries. It involves:
- Brief immobilization in a hinged knee brace for comfort and protected motion
- Progressive range of motion as tolerated
- A targeted physical therapy program for quadriceps activation, progressive strengthening, and neuromuscular retraining
- Gradual return to activity over four to eight weeks depending on grade
- Return to contact sport when pain-free valgus stress and full strength are documented
Surgical treatment is indicated for grade 3 injuries that fail to heal, for injuries with significant associated ligament disruption (ACL, PCL, or posterolateral corner), and for specific patterns in which the MCL tendon is displaced into the joint. Dr. Chudik performs MCL repair for acute injuries and MCL reconstruction with tendon graft for chronic instability.
Recovery and Outcomes
Grade 1 injuries typically allow return to sport within two to three weeks. Grade 2 injuries typically require three to six weeks. Grade 3 isolated injuries typically allow return in six to eight weeks. When associated ligament injury is present, recovery follows the longer timeline of the additional injury.
Outcomes for isolated MCL injuries are very good with non-surgical treatment. Outcomes after combined injury depend on the quality of reconstruction of the associated ligaments.
When to See Dr. Chudik
Schedule an evaluation after any knee injury with pain on the inside of the knee, if the knee feels unstable with cutting or pivoting, or if swelling and loss of motion have not resolved within a few days. Call 630-324-0402 or request an appointment online.