Todd A. Irwin, Abstract
Posterior malleolus fractures are a common component of ankle fractures. The morphology is variable; these fractures range from small posterolateral avulsion injuries to large displaced fracture fragments. The integrity of the posterior malleolus and its ligamentous attachment is important for tibiotalar load transfer, posterior talar stability, and rotatory ankle stability. Fixation of posterior malleolus fractures in the setting of rotational ankle injuries has certain benefits, such as restoring articular congruity and rotatory ankle stability, as well as preventing posterior talar translation, but current indications are unclear. Fragment size as a percentage of the anteroposterior dimension of the articular surface is often cited as an indication for fixation, although several factors may contribute to the decision, such as articular impaction, comminution, and syndesmotic stability. Outcome studies show that, in patients with ankle fractures, the presence of a posterior malleolus fracture negatively affects prognosis. Notable variability is evident in surgeon practice.