Figure 1. Anteroposterior radiograph of the right ankle.
Figure 2. Mortise radiograph of the right ankle.
Figure 3. Lateral radiograph of the right ankle.
A 17-year-old male patient presents with severe right ankle pain after sustaining a twisting injury at a trampoline park. Anteroposterior, mortise, and lateral radiographs of the right ankle are obtained (Figures 1, 2, and 3, respectively).
What type of fracture did this patient sustain?
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This patient was diagnosed with a Tillaux fracture, which occurs following an abduction-external rotation mechanism; this causes the anterior tibiofibular ligament to avulse the anterolateral corner of the distal tibial epiphysis. The fracture is a Salter-Harris III fracture of the anterolateral distal tibial epiphysis, which occurs in patients nearing skeletal maturity. It is seen more frequently in girls than in boys. Standard anteroposterior, lateral, and mortise view radiographs should be obtained in all pediatric patients with ankle injuries.
A Tillaux fracture appears as a vertical line through the epiphysis and is best seen on mortise view. Computed tomographic imaging studies are often obtained to help determine the degree of fracture displacement. Fractures with <2 mm of displacement can be treated in a non-weightbearing cast; however, closed-loop reduction is necessary for fractures displaced > 2 mm to restore the joint surface and prevent future degenerative joint disease. Displaced fractures can be reduced with internal rotation of the foot. Surgical fixation involves the placement of 1 or 2 screws across the epiphysis to hold the reduction in place. A triplane fracture is a multi-plane Salter-Harris IV fracture. A triplane fracture has a coronal plane fracture in the posterior distal tibial metaphysis, which distinguishes it from a Tillaux fracture.1,2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor-in-chief of the Journal of Orthopedics for Physician Assistants (JOPA).