Medial and lateral rotatory dislocations of the ankle after trivial trauma--pathomechanics and management of two cases.

Pure frontal plane rotatory dislocation of the ankle joint without an associated fracture is an extremely rare injury. We report one such case of an eversion rotatory dislocation and one case of an inversion rotatory dislocation. To our knowledge, this is the first report of an eversion injury resulting in dislocation of the ankle without fracture. Both patients had low energy trauma, predisposing ligamentous injuries, and recurrent sprains. In the patient with lateral rotatory dislocation, medial malleolar hypoplasia was also a contributing factor. Both patients healed the presenting index injury with nonoperative treatment, whereas the lateral rotatory dislocation had a lateral ankle stabilization to prevent subsequent injury.