A 13-year-old boy sustains an ankle injury while playing cricket. Radiographs show a vertically oriented fracture through the anterolateral portion of the distal tibial epiphysis extending into the physis and metaphysis. This injury results from avulsion of the anteroinferior tibiofibular ligament during external rotation, and occurs because:

• A The anterolateral part of the distal tibial physis is the last portion to close ✓
• B The entire distal tibial physis closes simultaneously
• C The peroneal nerve pulls the fragment laterally
• D The medial malleolar apophysis remains cartilaginous until adulthood

Explanation

The Tillaux fracture is a Salter-Harris III injury of the distal tibia seen between roughly 12 and 15 years, when the medial and central physis have fused but the anterolateral quadrant remains open. External rotation stresses the anteroinferior tibiofibular ligament, which avulses this unfused fragment. Asymmetric physeal closure, not simultaneous closure, creates the vulnerability.

Reference: Rockwood and Green's Fractures in Adults, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.