[Fracture of the posterior malleolus : A paradigm shift]

Ankle fractures with involvement of the posterior malleolus have a poor prognosis. The traditional concept of addressing the posterior fragment as the final step in the surgical reconstruction depending on the fragment size manifest in the lateral X‑ray, does not do justice to the anatomic and biomechanical relevance of the posterior malleolus. Intra-articular step-offs and fragment displacement ≥ 2 mm, impacted intercalary fragments, involvement of the fibular notch and instability of the syndesmosis, represent parameters relevant for the surgical reconstruction and the functional and radiomorphological outcome independent of fragment size. A valid assessment of these parameters can only be achieved via computed tomography (CT) including multiplanar 2D and 3D reconstruction. This is the foundation for the classification of posterior malleolar fractures according to Bartoníček et al., it forms the basis of the preoperative analysis of the fracture components and represents a decision-making tool for the indications for surgery. The individual fracture pattern guides the selection of the suitable approach or a combination of approaches and the surgical strategy. Making use of the posterior approaches enables the surgeon to have a direct view of the fracture components of the posterior malleolus as a precondition for an anatomic reduction. This central surgical step is frequently done as the first measure of the surgical reconstruction of the ankle joint. Furthermore, direct reduction and posterior stabilization is more accurate and stable than indirect reduction from an anterior approach with indirect fixation using lag screws. An additional temporary transfixation of the tibiofibular syndesmosis is often dispensable.