What's the diagnosis? By Dr. F. Jon Skilton

A 60 yo female presents with ankle pain after a fall from a ladder.  On exam patient has a grossly deformed left ankle and an inverted foot.  An xray is shown.  What's the diagnosis?  Scroll down for answer.







Answer:  Comminuted fracture of the talus with medial dislocation of the subtalar joint.  (Hawkins Type IV fracture of talus)

Subtalar dislocations

  • Rare, account for 1-2% of foot/ankle dislocations
  • There is disruption of the articulation of both the talocalcaneal and talonavicular joints
  • may appear as an ankle dislocation but tibiotalar and ankle mortise are intact
  • usually accompanied by fractures
  • approximately 25% are open at initial presentation
  • Medial subtalar dislocations (85%)
    • foot inverted, calcaneous displaced medially
    • AP xray will show medially displaced calcaneous as above and lateral will show talar head superior to navicular bone




  • Lateral subtalar dislocations (15%)
    • Foot is everted, calcaneous is displaced lateral to the talus
    • lateral xray will show talar head inferior to navicular
  • Prompt reduction is warranted with knee in flexion to relax the gastrocnemius
  • 30% require open reduction
  • High risk of infection for open fracture dislocation




Tintinalli's Emergency Medicine Manual, 8e Eds. Ch 175 Rita K. Cydulka, et al. New York, NY: McGraw-Hill

Giannoulis, Papadopoulus, Mavrodontitus, Subtalar dislocation without associated fractures: Case report and review of literature. World Journal of Orthopedics, 2015 April 18; 6(3): 374-379

Cervera, T. Subtalar Dislocation Case Report and Literature Review. Global Journal of Medical Research: Orthopedics and Musculoskeletal System

Eisenstein, Hillier, Ahmad, Medial subtalar dislocation with navicular and posterior talar process fracture: the first report in the literature, BMJ Case Report 2013: 2013: bcr2012007763