Skip to Main Content

Condition/Disorder Synonyms

  • Tibial collateral ligament sprain

ICD-9-CM Code

  • 844.1 Sprain of medial collateral ligament of knee

ICD-10-CM Code

  • S83.419A Sprain of medial collateral ligament of unspecified knee, initial encounter

Preferred Practice Pattern1

Key Features


  • Tear of the medial collateral ligament of the knee

  • May be graded based on extent of damage1,2

    • Grade I: localized tenderness with no instability

    • Grade II: localized tenderness, moderate fiber disruption; slight to moderate abnormal motion

    • Grade III: Complete fiber disruption; noted instability

Essentials of Diagnosis

  • Injury is generally traumatic and can occur at any age

  • Trauma is usually a high impact force applied to the lateral knee

  • The anterior cruciate ligament (ACL) and medial meniscus are commonly injured concurrently

  • Clinical diagnosis is generally made through history of injury and knee valgus stability testing

  • Diagnosis may be confirmed with magnetic resonance imaging (MRI)

General Considerations

  • Medial collateral ligament is most taut in knee extension

  • Commonly injured from an outside force hitting the lateral portion of the knee, ie. football tackle

  • Anterior fibers of superficial band is taut with flexion2


  • Most commonly injured knee ligament

  • Incidence (United States)2

    • Average 0.24 per 1000

    • Male = 0.36 per 1000, female = 0.18 per 1000

  • Most common in young athletic population

Clinical Findings

Signs and Symptoms

  • Medial knee pain

  • Pain with palpation over medial knee

  • Pain with valgus force to knee

  • Pain with extension and deep flexion

  • Feeling of instability or “giving way” in the knee

Functional Implications

  • Decreased squatting ability

  • Difficulty with transitioning from sit-to-stand or stand-to-sit

  • Pain with swinging legs in/out of car and/or bed

  • Decreased stability while walking on uneven surfaces

  • Decreased stability with change of direction

Possible Contributing Causes

  • Usually related to traumatic valgus stress applied to the knee2

    • Sports injury

    • Motor vehicle accident

  • May be related to severe degenerative osteoarthrosis

Differential Diagnoses

  • Medial joint line pain related to knee osteoarthrosis

  • Pes anserine bursitis

  • Adductor strain

  • Patellofemoral pain syndrome

  • Referred hip pain

Means of Confirmation or Diagnosis


  • MRI

  • Valgus stress radiograph

Findings and Interpretation

  • Valgus stress radiograph

    • Isolated injury of superficial MCL Increased medial gapping of 1.7 mm at 0˚ knee flexion

    • Increased medial gapping of 3.2 mm at 20˚ knee flexion

  • Complete injury of MCL

    • Increased ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.