Pylon fractures of the ankle: a distinct clinical and radiologic entity.

Pylon fractures are a distinct clinical and radiologic entity that should not be confused with trimalleolar fractures. Radiographic and clinical comparison of 20 surgically documented pylon and ten trimalleolar fractures revealed four major features of pylon fractures distinguishing them from trimalleolar fractures: (a) the presence of profound distal-tibial comminution, (b) intra-articular extension of tibial fractures through the dome of the plafond, (c) the presence of a fractured talus, and (d) anatomic relationship of the lateral malleolus to the talus at the level of the ankle mortise. With use of clinical history in addition to plain radiography, pluridirectional tomography, and computed tomography, these two fractures can be clearly separated. This distinction carries important surgical and prognostic implications.