Summary
Definition
The medial collateral ligament (MCL) is a supporting structure on the medial part of the knee joint. [Figure caption and citation for the preceding image starts]: Medial collateral ligament (right knee)Created by Sanjeev Bhatia, MD; used with permission [Citation ends].
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
- tenderness
- laxity on valgus stress testing
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
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
Diagnostic tests
1st tests to order
- plain x-rays of knee
- stress x-rays of knee
Tests to consider
- MRI of knee
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
Contributors
Authors
Sanjeev Bhatia, MD
Director, Hip & Knee Joint Preservation Center
Northwestern Medicine Central DuPage Hospital
Northwestern University Feinberg School of Medicine
Warrenville
IL
Disclosures
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
Professor
Department of Orthopedic Surgery
Section of Sports Medicine
Rush University Medical Center
Chicago
IL
Disclosures
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
Director
Joint Preservation Center at Peninsula Orthopedic Associates
Salisbury
MD
Disclosures
JMS declares that he has no competing interests.
Differentials
- Medial meniscus tear
- Soft tissue contusion of the medial knee
- Tibial plateau fracture
More DifferentialsGuidelines
- 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
Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer