Evaluation of the role of posterior malleolus fixation in trimalleolar ankle fractures: a prospective study

Abstract

Background: Trimalleolar ankle fractures are relatively rare and complex ankle injuries, the prognosis of which is worse than bimalleolar fracture. The three malleoli are bony restraints of the ankle and all three are fractured in trimalleolar fractures. Hence, there is disruption of the weight bearing portion of the tibial plafond along with talus dislocation/subluxation. Management of such fractures is challenging and confounded by the dilemma of posterior malleolus fixation. Aim: The aim of the present study was to evaluate the radiological and clinical outcome of fixation of large (>25%) posterior malleolus fragment in trimalleolar fractures. Methods: 25 patients underwent fixation of the three malleoli and evaluated prospectively. Different methods for fixation from plating to lag screws were used for posterior malleolus. Results: 92% of patients in our series had excellent to good clinical outcome. Radiologically, there was anatomical reduction of the ankle joint and none of the patient had postoperative talus subluxation or arthrosis. Conclusions: Our study shows that there is consistent and reproducible clinical advantage of fixing the posterior malleolus in trimalleolar ankle fractures.