Infrasyndesmotic, medial fracture with lateral fracture/avulsion
Introduction
If the lateral injury involves an avulsion fracture of the tip or a transverse fracture of the lateral malleolus, with a medial malleolar fracture (oblique or vertical), this is classified as an AO/OTA 44A2.2 or an AO/OTA 44A2.3 fracture.
In these fractures, the superomedial corner of the talus may cause, not only a high oblique or vertical medial malleolar fracture, but also an impaction fracture of the “medial corner” of the tibia, at the junction of its horizontal joint surface (plafond) and the medial malleolar joint surface (see x-ray for 44A2.3 fractures). The impacted “corner” fragment will need to be reduced, prior to reduction and fixation of the medial malleolus.
Avulsion of the tip of the lateral malleolus
If the lateral injury involves an avulsion fracture of the tip of the lateral malleolus, with a medial malleolar fracture (oblique or vertical), this is classified as an AO/OTA 44A2.2 fracture.
Transverse fracture of the lateral malleolus
If the lateral injury involves a transverse fracture of the lateral malleolus, with a medial malleolar fracture (oblique or vertical), this is classified as an AO/OTA 44A2.3 fracture.
In these fractures, the superomedial corner of the talus may cause, not only a high oblique or vertical medial malleolar fracture, but also an impaction fracture of the “medial corner” of the tibia, at the junction of its horizontal joint surface (plafond) and the medial malleolar joint surface. This is effectively a “split depression” injury, analogous to that of the tibial plateau. The impacted “corner” fragment will need to be reduced, prior to reduction and fixation of the medial malleolus.
