A pilon fracture is a fracture of the distal tibia involving the tibial plafond. Obviously there is some potential overlap with the more severe malleolar fractures; pilon fractures are usually understood to be those with involvement of the central plafond, although this has not been formally defined.
Pilon fractures account for about 5% of tibial fractures. It is difficult to estimate incidence accurately because almost all reported series are from major trauma centres and hence represent a very selected population.
Biomechanics
Ruedi and Allgower reported a seminal series of pilon fractures in 1980, most of which were low-energy twisting factures. However, almost every other series has found that a large majority of pilon fractures are caused by high-energy axial impaction injuries, with motor vehicle accidents and falls from 3 metres or more the commonest mechanisms of injury.
Pre-tensioning of the Achilles tendon and the position of the ankle and foot at the moment of impact may have an effect on the severity and anatomy of the fracture