Talus fractures

Talus fractures are rare and make up less than 1% of all fractures. They are generally caused by high-energy trauma (e.g., due to motor vehicle collisions) or axial loading injuries (e.g., snowboarder's ankle). Talus fractures are classified according to their anatomical location as head, neck, body, osteochondral, lateral, and posterior process fractures. Clinical features include acute pain or tenderness around and/or below the ankle, swelling and ecchymosis around the ankle, restricted range of motion, and inability to bear weight on the affected ankle. Plain x-ray series are usually diagnostic, but a CT scan may be necessary to assess the articular involvement and characterize the fracture. Conservative treatment is recommended for stable and nondisplaced fractures and typically involves a non-weight-bearing, short leg cast for 6–8 weeks. Surgery is the definitive treatment, indicated especially for open or displaced fractures. Complications include avascular necrosis, posttraumatic arthritis, and union issues (e.g., malunion, nonunion).

• Prevalence: < 1% of all fractures

Epidemiological data refers to the US, unless otherwise specified.

• High energy trauma: fall from a height, motor vehicle collision
• Axial loading: sports injuries (esp. snowboarder's ankle)

• Acute pain or tenderness around and/or below the ankle
• Swelling around the ankle
• Hematoma, ecchymosis
• Restricted range of motion
• Inability to bear weight on the affected ankle

Physical examination

• Assess concomitant injuries (e.g., soft tissue injury)
• Assess range of motion
• Assess for neurovascular compromise (e.g., nerve integrity, distal pulses, capillary refill) and compartment syndrome

Imaging ^[2]

• Plain x-ray series
  • AP, lateral, and mortise views of the ankle
  • AP, lateral, and oblique views of the foot
  • Canale view: used when there is a high suspicion of talar neck fractures or if CT imaging is unavailable
• CT scan (confirmatory test): used to assess articular involvement and characterize fracture
• MRI
  • If symptoms persist after 4–6 weeks
  • High clinical suspicion despite negative x-ray

Conservative

• Technique: non-weight-bearing, short leg cast usually for 6–8 weeks (talar neck fractures up to 12 weeks)
• Indications: stable or nondisplaced fractures
• Other
  • Pain management (NSAIDs, opioids, local anesthetics)
  • Physical therapy

Surgical ^[2]

• Procedure: open reduction and internal fixation
• Indications
  • Open fractures
  • Displaced fractures (> 2 mm)
  • Comminuted fractures
  • Neurovascular injury
  • Associated dislocation

• Avascular necrosis
• Posttraumatic arthritis (e.g., talonavicular, subtalar arthritis)
• Delayed union, malunion, nonunion
• Chronic pain
• Infection

We list the most important complications. The selection is not exhaustive.

• Talar head fractures have a better prognosis than talar neck fractures
• Hawkins sign: subchondral radiolucency of the talar dome secondary to subchondral atrophy
  • Usually seen 6–8 weeks after injury
  • A negative sign indicates inadequate vascularity of the talus
• Hawkins-Canale classification: classification system for talar neck fractures with high prognostic value, as the degree of malalignment correlates with the risk of avascular necrosis