How to address the posterior malleolus in ankle fractures? A decision-making model based on the computerised tomography findings

Introduction The posterior malleolus (PM) is affected in around the 40% of ankle fractures. Anatomical reduction of the articular surface and fibular notch are essential for ankle stability and functional outcomes. These facts justify the increasing interest in the surgical treatment of PM in ankle fractures. Within this context, pre-operative computed tomography (CT) images and posterior approaches to the ankle play a crucial role. The aim of this paper is to make an accurate description of the literature and describe, according to authors' experience, the best surgical approach to the PM based on the CT findings while assessing their advantages and disadvantages. Methods The fracture pattern of PM is classified according to Haraguchi or Bartonicek classification, both based on pre-operative CT scan images. The posterolateral (PLA) and posteromedial (PMA) approaches to the ankle and their corresponding modifications are described. We propose a decision-making algorithm for posterior malleolus fractures to facilitate treatment selection. Results Posterolateral approach should be the election for Haraguchi I or III and Bartonicek 1, 2, or 4 fractures. Percutaneous PLA might be adequate in Haraguchi I and Bartonicek 1 to improve syndesmotic stability. In PL approaches, the fibula fracture may be addressed and fixed with a posterolateral plate or through a subcutaneous window that allows lateral reduction and fixation. Posteromedial approach should be the election for Haraguchi II and Bartonicek 3 fractures. A modified PMA might be the election to reduce and fix any fragment dependent on the anterior inferior tibiofibular ligament (AITFL). The modified PMA is performed in a supine position and allows us to check the articular reduction under direct vision. Both PMA are associated with a lateral fibular approach. Conclusion To address the posterior malleolus when treating ankle fractures, surgeons should choose the most adequate approach based on the fracture pattern and their own experience. Anatomical reduction and stable fixation are critical to improve outcomes.