Ankle syndesmosis injury

Background

  • 5-18% of all ankle sprains injure the distal tibiofibular syndesmosis [1]
  • Highly unstable if the deltoid ligament is injured as well
  • Mechanism is via external rotation and hyperdorsiflexion
  • Associated with Maisonneuve fracture

Clinical Features

  • Toe walking: to prevent painful dorsiflexion
  • External rotation stress test: flex knee at 90 degrees then externally rotate the foot
  • Squeeze/Hopkin's test: compress mid/proximal calf to separate the tibia and fibula distally

Differential Diagnosis

Other Ankle Injuries

Distal Leg Fractures

Foot and Toe Fractures

Hindfoot

Midfoot

Forefoot

Evaluation

  • Decreased tibio-fibular overlap (normally >6mm on AP films measured 1 cm proximal from the tibial plafond) [2]
  • Increased tibio-fibular syndesmosis clear space (normally <6mm on AP films measured 1 cm proximal from the tibial plafond)
  • Increased medial clear space (normally <5mm)

Management

Disposition

  • Orthopedic follow up. May need screw fixation if joint is subluxed

See Also

External Links

https://emergencymedicinecases.com/episode-58-tendons-ligaments-missed-orthopedic-injuries/

References

  1. Lin, CF, Gross, ML, & Weinhold, P. Ankle syndesmosis injuries: Anatomy, biomechanics, mechanism of injury, and clinical guidelines for diagnosis and intervention. 2006. J Orthop Sports Phys Ther, 36(6): 372-84
  2. Heest, TJ & Lafferty, PM. Injuries to the ankle syndesmosis. 2014. J Bone Joint Surg Am, 96(7): 603-13