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  • Inversion ankle sprain
  • Lateral ankle sprain
  • ATFL sprain
  • ATFL tears

  • 845.0 Ankle sprain

  • S93.409A Sprain of unspecified ligament of unspecified ankle, initial encounter


  • Disruption of anterior lateral ligament of the ankle
    • May be acute or chronic
  • The anterior talofibular ligament (ATFL) restricts anterior translation of the talus
  • The ATFL also restricts inversion and adduction at the subtalar joint
  • Most commonly injured with rapid inversion, adduction, and plantarflexion movements, in either contact or non-contact situations
  • Pain and edema at lateral ankle
  • Can occur with structure progression to the calcaneofibular ligament and then posterior talofibular ligament

Essentials of Diagnosis

  • Positive anterior drawer test and talar tilt test
  • Ultrasonography, radiography, or MRI may be utilized in select cases.2
    • Ultrasonography or MRI is recommended following an inversion ankle sprain in a patient with chronic ankle instability
    • Radiographs utilized within the constraints of Ottawa ankle rules
    • ATFL tears are classified based on the anatomical degree of damage or functional stability found on clinical exam
    • Anatomical
      • Grade 1: partial microscopic tearing of the ligament, minimal to no loss of function, mild swelling and pain
      • Grade 2: partial macroscopic tearing of the ligament, with mild-moderate loss of function, moderate swelling/pain/tenderness
      • Grade 3: complete rupture with severe loss of function, severe swelling/pain/tenderness
    • Functional stability
      • Stable: no laxity with talar tilt or anterior drawer testing (Grade I)
      • Unstable: laxity with anterior drawer testing (ATFL, Grade II); laxity with both anterior drawer and talar tilt (ATFL and CF, Grade III)

General Considerations

  • May occur with concomitant calcaneofibular (CF) sprain, posterior talofibular sprain, synovitis, chondral lesion, or fracture
  • Most commonly sprained ankle ligament


  • Prevalent in athletes, though does occur in sedentary individuals
    • Most common in basketball, soccer, and football4
  • Males between 15 and 24 years old have higher rates of ankle sprains than female counterparts; females over 30 years old have higher rates than male counterparts.4
  • A previous ankle sprain is the strongest predictor of a subsequent ankle sprain.5

Signs and Symptoms6

  • Pain in lateral ankle or foot
    • Grade 1: minimal
    • Grade 2: moderate
    • Grade 3: severe
  • May posture in greater pronation to avoid plantarflexed/inversion moments
  • Edema lateral ankle
    • Grade 1: minimal
    • Grade 2: moderate
    • Grade 3: severe
  • Pain with palpation of ATFL
  • Possible inability to bear partial or full weight
  • Guarded active/passive inversion range of motion (ROM)
  • May have increased inversion passive ROM (positive Talar tilt test)
  • Decreased active/passive dorsiflexion ROM
  • Decreased peroneal/eversion strength
  • In moderate to severe cases, increased talar anterior glide on mortise (positive anterior drawer test)

Functional Implications6

  • Loss of functional ...

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