Surgical Treatment of Posterior Malleolus Fractures and Posterior Fixation

Abstract

Posterior malleolar fractures (PMFs) have been demonstrated to result in poorer outcomes than other types of ankle fractures with a higher incidence of posttraumatic arthritis. Accordingly, there has been a recent surge in interest in reduction and fixation of PMFs. Operative criteria for PMFs have been based on size, step-off, ankle joint instability, and syndesmotic injury, though universally accepted criteria have yet to be defined. Anatomically, the posterior malleolus is important as an insertion point of the posterior inferior tibiofibular ligament and thereby may play a role in syndesmotic stability. However, the important lateral ankle ligament complex is also important in governing stability of the talus within the ankle mortise. PMFs have been classified by the Haraguchi system based on morphology and extent. Radiographs, although always appropriate to perform as the initial diagnostic imaging study, are likely insufficient to evaluate the size and displacement; computed tomography scan is recommended for optimal evaluation for preoperative planning. When treating the posterior malleolus by a posterolateral approach, prone and lateral positioning of the patient facilitates exposure, although it can also be performed in the supine position with a large bump and with a leg that can be safely passively internally rotated sufficiently, or externally rotated if a posteromedial approach is used. Fixation can be performed with lag screw fixation alone versus buttress or standard plating techniques. Wound complications and posttraumatic arthritis are relatively common complications encountered in the treatment of PMFs. Level of Evidence: Diagnostic Level V. See Instructions for Authors for a complete description of levels of evidence.