Ankle sprain


Ankle stabilization anatomy

Ankle anatomy.png
  • Syndesmosis
  • Ligaments
    • Medial: Medial collateral (deltoid) ligament (tibia to talus and calcaneus)
    • Lateral: Anterior/posterior talofibular, calcaneofibular ligaments

Clinical Features

Right foot with acute lateral ankle sprain.

Lateral Ankle Sprain

  • Most common
  • Due to inversion of plantarflexed ankle
  • Anterior talofibular ligament (ATFL) is most commonly injured ligament

Medial Ankle Sprain

  • Isolated sprain is unusual; often associated with fibular fracture or syndesmosis injury
  • Always rule-out Maisonneuve fracture by evaluating proximal fibula

Syndesmotic Sprain ("High-ankle sprain")

  • Associated with with hyperdorsiflexion when talus moves superiorly and separates tibia/fibula
  • Pain just above talus

Differential Diagnosis

Other Ankle Injuries

Distal Leg Fracture Types

Foot and Toe Fracture Types





  • Anterior drawer test
    • Tests anterior talofibular ligament
    • Cup heel with one hand and and pull anteriorly while pushing tibia posteriorly
  • Talar tilt test
    • Tests for combined injury of anterior talofibular and calcaneofibular ligaments
    • Inversion at the ankle causes tilting/lifting of the mortise joint


Ottawa ankle rule

Ottawa ankle rule

Ankle x-ray needed if:

  • Pain near the maleoli AND
  • Inability to bear weight immediately and in the ED (4 steps) OR
  • Tenderness at posterior edge or tip of lateral malleolus OR
  • Tenderness at posterior edge or tip of medial malleolus

Ottawa foot rules

Ottawa foot rules

Foot x-ray series needed if:

  • Pain in the midfoot AND
  • Inability to bear weight both immediately and in the ED (4 steps) OR
  • Tenderness at the navicular OR
  • Tenderness at the base of the 5th metatarsal


  • Age <6 or >55
  • Only for blunt trauma mechanism
  • Does not apply to subacute/chronic injuries
  • Does not apply to injuries of the hindfoot or forefoot


  • Grade I
    • No tearing of ligaments
    • Minimal pain, swelling, ecchymosis; weightbearing is tolerable
    • No splinting/casting; weight bearing as tolerated, isometric exercises, full ROM and stretching/strengthening exercises
  • Grade II
    • Partial ligament tear; possible instability
    • Increased pain, swelling, ecchymosis; difficulty bearing weight
    • Immobilize with air splint; PT with ROM/stretching/strengthening exercises
  • Grade III
    • Complete ligament tear; significant instability
    • Severe pain, swelling, ecchymosis; inability to bear weight
    • Immobilization and possible surgery; PT same as grade 2 but longer time period


  • Stable joint and ability to bear weight: (Likely Grade I)
    • NSAIDs, RICE (rest, ice, compression, elevation)
    • 1 week follow up if no improvement
  • Stable joint but unable to bear weight or unstable joint (Grades II and III) :
    • Ankle cast immobilization or a removable walking boot for 7-10 days for grades II and III. Follow up at 5 days with ortho/podiatry. [1]
    • Posterior mold splint and ortho consult/referral


  • Discharge

See Also