Ankle Sprain

Description

• Injuries to ligamentous supports of the ankle
• Ankle joint is a hinge joint composed of the tibia, fibula, and talus
• Injuries may range from stretching with microscopic damage (grade I) to partial disruption (grade II) to complete disruption (grade III)

Etiology

• Forced inversion or eversion of the ankle
• Forceful collisions
• 85–90% of ankle sprains involve lateral ligaments usually after an inversion injury:
  • Anterior talofibular (ATFL)
  • Posterior talofibular (PTFL)
  • Calcaneofibular (CFL)
  • The ATFL is the most commonly injured
  • If the ankle is injured in a neutral position, the CFL is often injured
  • The PTFL is rarely injured alone
• Injury to the deltoid ligament (connecting the medial malleolus to the talus and navicular bones) is usually the result of an eversion injury:
  • Often associated with avulsion at the medial malleolus or talar insertion
  • Rarely found as an isolated injury
  • Suspect associated lateral malleolus fracture or fracture of the proximal fibula (Maisonneuve fracture)
• Syndesmosis sprains (injury to the tibiofibular ligaments or the interosseous ligament of the leg):
  • Occur most commonly in collision sports
  • Syndesmosis injuries (“high ankle sprains”) have a higher morbidity and potential for long-term complications

• Children <10 yr with traumatic ankle pain and no radiologic evidence of fracture may have a Salter–Harris I fracture
• The ligaments are actually stronger than the open epiphysis