Research advances of the classification and treatment of posterior malleolus fractures

Abstract

The posterior malleolus plays an important role in the stability and function of the ankle joint. Approximately 7% to 44% of ankle joint fractures are accompanied by posterior malleolus fractures. The current published data suggest a poor outcome for ankle fractures involving the posterior malleolus. Inappropriate reduction of the posterior malleolus fragment may result in symptomatic malunion requiring corrective osteotomy. The posterior malleolus fractures were categorized into three types by Haraguchi: the posterolateral-oblique fractures(Type I), the transverse medial-extension fractures(Type II)and the small-shell fractures(Type III). Mangnus divided posterior malleolus fractures into two basic types: posterolateral and posteromedial types. Bartonicek classified the posterior malleolus fractures into four types on the basis of CT scan and 3D reconstructions, and taking into account the location, shape, size of the fragment and the integrity of the fibular notch: extraincisural fragment with an intact fibular notch(Type I), posterolateral fragment extending into the fibular notch(Type II), posteromedial two-part fragment involving the medial malleolus(Type III)and large posterolateral triangular fragment(Type IV). The fracture lines associated with posterior malleolus fractures appear to be highly variable. So far, no generally accepted clinically relevant classification of posterior malleolus fractures exists, and the indications of the operative management of these fractures were often determined by the size of the fragment. The anteroposterior and lateral views were used to evaluate the fractures of the fibular and the medial malleolus, as well as the rupture of the ligament and the presence of subluxation or dislocation of the talus. The determination of proper surgical approach and the internal fixation should take into account the size, shape and displacement of the posterior fragment by CT scans, through CT and 3D reconstructions. The aim of treatment for posterior malleolus fractures is to reduce the displaced fragments ana-tomically, and to restore the stability of the tibiotalar joint and the distal tibiofibular syndesmosis.