Image diagnosis: ankle fractures and dislocations.

Sundeep r Bhat, MD, is an Emergency Medicine Resident in the Stanford/Kaiser Emergency Medicine Residency Program. E-mail: [email protected]. Gus M Garmel, MD, fACEP, fAAEM, is a Senior Emergency Medicine Physician at the Santa Clara Medical Center. He is also the Co-Program Director of the Stanford/Kaiser Emergency Medicine Residency Program, and an Associate Professor of Emergency Medicine (Surgery) at Stanford University. He is a Senior Editor for The Permanente Journal. E-mail: [email protected]. Figure 1. Anterior-posterior view of the ankle Standard radiographs for suspected ankle injury include anteriorposterior (AP), lateral, and mortise views.1,2 On this AP radiograph, the solid white arrow demonstrates a subtle fracture of the distal fibula; the ankle mortise is intact. On AP ankle films, cortical disruption or talar tilt should be identified. If tibiofibular overlap (TFO)—the distance between the lateral border of the tibia and the medial border of the fibula—is less than 10 mm, or the tibiofibular clear space (TCS)—the distance between the medial border of the fibula and the lateral aspect of the posterior tibial malleolus—is greater than 5 mm, associated syndesmotic injury is likely. Greater than 2 mm difference between the lateral and medial joint space above the talus indicates talar tilt suggestive of medial or lateral disruption of this joint.1,2