Ankle sprain

Background

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

Clinical Features

• 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 w/ fibular fx or syndesmosis injury
  • Always rule-out Maisonneuve fx of proximal fibula
• Syndesmotic Sprain ("High-ankle sprain")
  • Assoc w/ hyperdorsiflexion when talus moves superiorly and separates tibia/fibula
  • Pain just above talus

Diagnosis

• Anterior drawer test
  • Tests anterior talofibular ligament
  • Cup heel w/ 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

Classification

• Grade I
  • No tearing of ligaments
  • Minimal pain, swelling, ecchymosis; weightbearing is tolerable
• Grade II
  • Partial ligament tear
  • Increased pain, swelling, ecchymosis; difficulty bearing weight
• Grade III
  • Complete ligament tear
  • Severe pain, swelling, ecchymosis; inability to bear weight

Management

• Stable joint and ability to bear weight:
  • NSAIDs, RICE (rest, ice, compression, elevation)
  • 1 week f/u if no improvement
• Stable joint but unable to bear weight:
  • Ankle brace w/ f/u in 1wk
• Unstable joint
  • Posterior mold splint and ortho consult/referral

See Also

• Ankle (Main)
• Ottowa Ankle Rules

Source

• Tintinalli