561 A Morphological Review of Medial Malleolar Fractures – a Large Single Centre Series

Abstract

Background: Medial Malleolus Fractures (MMF) are frequently managed by orthopaedic surgeons and are one of the most treated fractures of the ankle. Many approaches to management are described in the literature however, their morphology is under investigated. Method: Patients who had surgical fixation of their MMF were identified from 2012 to 2022. Analysis of their pre-operative, intra-operative and post-operative radiographs was performed. Lauge-Hansen classification was used to characterise ankle fracture morphology and Herscovici classification to characterise MMF morphology. Results: A total of 647 patients were identified across a 10-year period who had sustained a medial malleolar fracture. The most common Herscovici fracture in Supination Adduction injuries was a Herscovici D (43.9%, 17/39), in supination external rotation injuries was Herscovici C (52.75%, 259/491), in pronation external rotation injuries was Herscovici C (48.81%, 41/84) and in pronation abduction injuries was Herscovici B (45.45%, 12/33). Medial wall blowout occurred in 19.23%, occurring in supination adduction injuries most commonly (51.28%, 20/39). Herscovici A fractures were significantly more malreduced at time of surgery compared to other fracture types (21.88%, 7/32, p = .003). There was no significant difference in union rates across the classification groups (range 11.67% Herscovici D to 22.86% for Herscovici B). Conclusions: Knowledge of the medial malleolar morphology allows greater assessment and planning in their surgical treatment. There was a high rate of medial wall blowout even in the non-adduction fracture types, and this should be assessed to prevent over compression during surgical treatment. Herscovici A fracture malunions may need further investigation and different methods of fixation.