Occurs when excessive valgus stresses or external rotation forces are placed on the knee joint.
The most common symptom is medial-sided knee pain above or below the joint line. Patients are usually able to walk.
Diagnosis and grading is primarily made with history taking and physical exam.
Most patients are treated nonoperatively.
Prognosis for isolated medial collateral ligament injuries is good. Most patients return to sports within 3 to 6 weeks and to preinjury levels within 3 months.
Combined multiligament and chronic medial collateral ligament injuries often require operative intervention.
The medial collateral ligament (MCL) is a supporting structure on the medial part of the knee joint. Its primary function is to resist valgus (twisting outward away from the midline) and external rotation forces of the tibia in relation to the femur. The mechanism for MCL injury is typically a large valgus and/or external rotation force that is suddenly placed on the knee joint. Injuries to the MCL range in severity from a few torn fibers to complete disunity of the ligament.
History and exam
Key diagnostic factors
- injury due to excessive or repetitive valgus loading of MCL
- medial knee pain
- joint effusion
- laxity on valgus stress testing
Other diagnostic factors
- audible pop or tearing sensation at time of injury
- difficulty walking
- instability symptoms of knee
- mechanical knee symptoms
- knee deformity
- positive anterior drawer test
- positive posterior drawer test
- positive Lachman test
- positive pivot shift test
- joint line tenderness
- chronic pain
- participation in activities involving valgus stress at the knee joint
- age 20 to 35 years
- age 55 to 70 years
- weak muscles that cross the medial aspect of knee
1st investigations to order
- plain x-rays of knee
- stress x-rays of knee
Investigations to consider
- MRI of knee
- diagnostic ultrasound
isolated grade I injury
isolated grade II injury
isolated grade III injury
MCL + anterior cruciate ligament (ACL) combined injury
MCL + nonanterior cruciate ligament (ACL) combined injury
persistent high-grade valgus laxity after ≥3 months
- Medial meniscus tear
- Soft tissue contusion of the medial knee
- Tibial plateau fracture
- Management of anterior cruciate ligament injuries: evidence-based guideline
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