If the lateral malleolus is intact, and the lateral injury involves a rupture of the lateral collateral ligaments (the calcaneo-fibular ligament and the anterior and posterior talo-fibular ligaments), with a posteromedial malleolar fracture, this is classified as an AO/OTA 44A3.1 fracture.
In some cases, the medial fracture may cause a circumferential lesion, with a posterior extension. These are classified as AO/OTA 44A3 fractures. There is no special fracture type in the Lauge-Hansen classification of supination-adduction fractures that describes this posterior marginal extension of the medial lesion. Complete radiological evaluation (AP, lateral and AP with internal rotation) is crucial for correct classification and decision making.