Quadrimalleolar Fractures of the Ankle: Principles and Medium-Term Results of Surgical Fixation

CATEGORY: Ankle; Trauma INTRODUCTION/PURPOSE: Over the last decade, much attention has been paid to the fractures of the posterior malleolus as it became obvious that the mere presence of a posterior tibial fragment is associated with a less favorable prognosis in malleolar fractures. It seems logical to pay the anterior restraints of the ankle joint a similar attention as to the posterior ones. The anteriolateral distal tibia may be considered a 'fourth' or anterior malleolus. Here, we present a technique of fixation of trimalleolar fractures with additional fracture of the anterior tibial tubercle ('quadrimalleolar') or anterior fibular rim ('quadrimalleolar equivalent'). METHODS: Twenty-four patients with a mean age of 60 years were treated with open reduction and internal fixation of all 4 malleoli. There were 17 quadrimalleolar and 6 quadrimalleolar equivalent fractures. One patient had both anterior tibial and fibular avulsion fractures in addition to a trimalleolar ankle fracture. Surgical approaches and internal fixation were tailored individually. Twenty patients were operated in prone position with direct fixation of the posterior malleolus and 4 patients in supine position with indirect anterior to posterior screw fixation of the posterior malleolus under transfibular control of reduction. RESULTS: After fixation of al 4 malleoli, only one patient (4%) required a syndesmotic screw for residual syndesmotic instability on intraoperative testing. There were no infections, and no wound healing problems. All patients went on to solid union. No late fusions were needed. Nineteen patients (79%) could be reevaluated after a mean of 77 months (range, 15 to 156 months) follow- up. The Foot Function Index averaged 15 (range, 50 to 0), the Olerud and Molander Score averaged 79 (range, 45 to 100) and the AOFAS Ankle and Hindfoot Scale averaged 87 (range, 39 to 100). CONCLUSION: Fixation of the anterior and posterior tibial fragments increases syndesmotic stability by providing a bone-to-bone fixation. Reduction of displaced anterior and posterior tibial rim fractures restores the physiological shape of the tibial incisura and therefore facilitates fibular reduction. In the majority of cases, this also restores articular congruity of the lateral tibial plafond. Anatomic reduction of the anterior and posterior malleolus in addition to medial and lateral malleolar fixation leads to favourable functional results despite a complex (quadrimalleolar) fracture pattern.