Case report: distal pronation abduction ankle fracture.

Abstract

Various ankle fracture classifications have been created to help facilitate communication, research, and treatment. Multiple variant patterns have also been described. This report discusses a variant injury, the distal pronation abduction ankle fracture. The distal pronation abduction ankle fracture consists of the following components: 1) transverse, comminuted Weber A distal fibular fracture. Concomitant impaction injury to the anterolateral plafond or talar dome may accompany this compression-sided fracture. 2) Complete avulsion of the superficial and deep deltoid ligament origins. 3) Medial Gustilo Anderson type 3A transverse wound with the medial malleolus and plafond, stripped bare of ligamentous restraint, extruded. This injury pattern presumably results from a primarily valgus force at the level of the tibiotalar articulation, resulting in compression and a resultant comminuted fibula fracture in a more distal location than standard pronation abduction fractures. Two cases are illustrated. The distal pronation abduction ankle fracture is distinguished by a comminuted Weber A fibula fracture. Standard fixation techniques result in satisfactory outcomes, although injury complexity should not be underestimated, as the degree of comminution and distal nature of the fibula fracture pattern require a more nuanced approach than is required for routine rotational fractures.