Sprain, anterior talofibular ligament (ATFL)

• 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

• 4E: Impaired joint mobility, motor function, muscle performance, and range of motion associated with connective tissue dysfunction

Description

• 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

Demographics

• 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 ...