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Medial collateral ligament injury

Last reviewed: 4 Sep 2023
Last updated: 02 Jun 2023



History and exam

Key diagnostic factors

  • injury due to excessive or repetitive valgus loading of MCL
  • medial knee pain
  • joint effusion
  • tenderness
  • laxity on valgus stress testing
More key diagnostic factors

Other diagnostic factors

  • ecchymosis
  • 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
Other diagnostic factors

Risk factors

  • 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
More risk factors

Diagnostic investigations

1st investigations to order

  • plain x-rays of knee
  • stress x-rays of knee
More 1st investigations to order

Investigations to consider

  • MRI of knee
More investigations to consider

Emerging tests

  • diagnostic ultrasound

Treatment algorithm


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



Sanjeev Bhatia, MD
Sanjeev Bhatia

Director, Hip & Knee Joint Preservation Center

Northwestern Medicine Central DuPage Hospital

Northwestern University Feinberg School of Medicine




SB receives publication royalties from the following Nova publication: Ligamentous Injuries of the Knee. SB has stock ownership in: AI Digital Ventures, LLC; Edge Surgical; TDA Ventures, LLC; and Joint Preservation Innovations, LLC. SB is on the Board of Directors for AI Digital Ventures, LLC and Joint Preservation Innovations, LLC. He also holds patents pertaining to bone resection related technology. He has received other financial or material support from Smith & Nephew and Graymont Medical, LLC, and has been a paid speaker for the latter. SB also is a board or committee member for the American Academy of Orthopaedic Surgeons and the Arthroscopy Association of North America.

Nikhil N. Verma, MD
Nikhil N. Verma


Department of Orthopedic Surgery

Section of Sports Medicine

Rush University Medical Center




NNV declares the following competing interests: American Orthopaedic Society for Sports Medicine: board or committee member; American Shoulder and Elbow Surgeons: board or committee member; Arthrex, Inc: research support; Arthroscopy: editorial or governing board; publishing royalties, financial or material support; Arthroscopy Association Learning Center Committee: board or committee member; Arthrosurface: research support; Cymedica: stock or stock options; DJ Orthopaedics: research support; Journal of Knee Surgery: editorial or governing board; Minivasive: paid consultant, stock or stock options; Omeros: stock or stock options; Orthospace: paid consultant; Ossur: research support; SLACK Incorporated: editorial or governing board; Smith & Nephew: IP royalties, paid consultant; Smith & Nephew, Athletico, ConMed Linvatec, Miomed, Mitek: research support; Vindico Medical-Orthopedics Hyperguide: publishing royalties, financial or material support.

Peer reviewers

Jason M. Scopp, MD


Joint Preservation Center at Peninsula Orthopedic Associates




JMS declares that he has no competing interests.

  • Medial collateral ligament injury images
  • Differentials

    • Medial meniscus tear
    • Soft tissue contusion of the medial knee
    • Tibial plateau fracture
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  • Guidelines

    • The posteromedial corner of the knee: an international expert consensus statement on diagnosis, classification, treatment, and rehabilitation
    • Treatment of combined injuries to the ACL and the MCL complex: a consensus statement of the Ligament Injury Committee of the German Knee Society (DKG)
    More Guidelines
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