Posterior Malleolar Fractures: Current Concepts in Classification, Diagnosis, and Management

Posterior malleolar fractures (PMF) accompany 7-44% of ankle fractures and remain controversial in terms of treatment. This review summarizes current concepts in classification, diagnosis, and management of posterior malleolar fractures. The anatomical importance of the posterior malleolus is emphasized, particularly as the posterior tibiofibular ligament contributes to 42% of syndesmotic stability. For diagnosis, three-dimensional computed tomography (3D CT) imaging is considered the gold standard in addition to standard radiographs. The three most commonly used classification systems are Haraguchi, Bartoníček/Rammelt, and Mason classifications. The treatment approach should be based on multifactorial evaluation including fracture morphology, joint incongruity, posterior subluxation, and syndesmotic instability, rather than fragment size alone. Conservative treatment is appropriate for minimally displaced fractures, while surgical indications include fragments comprising more than 25% of the joint surface, displacement greater than 2 mm, or syndesmotic instability. Surgical treatment modalities include closed reduction with screw fixation, posterolateral, and posteromedial open approaches. Long-term studies have reported generally favorable functional outcomes after appropriately managed ankle fractures with posterior malleolar fragments; however, residual articular incongruity, fracture-dislocation, and inadequate reduction have been associated with poorer long-term outcomes and post-traumatic osteoarthritic changes. In conclusion, individualized treatment strategies and restoration of joint congruence are critical for optimal outcomes.