RESUMO
Ankle fractures account for 9 % of fractures (Clare in Foot Ankle Clin 13(4):593-610, 1) representing a significant portion of the trauma workload; proximal femoral fractures are the only lower limb fracture to present more frequently. Ankle fractures have a bimodal age distribution with peaks in younger males and older females (Arimoto and Forrester in AJR Am J Roentgenol 135(5):1057-1063, 2). There has been threefold increase in the incidence among elderly females over the past three decades (Haraguchi and Armiger in J Bone Joint Surg Am 91(4):821-829, 3). In 1950, Lauge-Hansen devised a classification of ankle fractures based on the position of the foot and the deforming force at the time of injury. This has been widely accepted by orthopedists, but is not in general use by radiologists. Identification of the fractures and classification of the type of injury allows diagnosis of the otherwise occult ligamentous injuries. Three radiographic views of the ankle (anteroposterior, mortise, and lateral) are necessary to classify an injury with the Lauge-Hansen system. Two additional criteria are also necessary: the position of the foot at the time of injury and the direction of the deforming force.