Direct posterior reduction in a case of posttraumatic irreducible lateral atlantoaxial dislocation.

Posttraumatic true irreducible C1-2 lateral dislocation is rare. The mechanism of injury is likely to be different for this kind of dislocation. The management of such an injury and the technique for direct posterior reduction remain unclear because of its rarity. The authors describe the case of a 34-year-old man who sustained injury in a vehicular accident, leading to neck pain. Radiological studies revealed fixed right lateral and posterior C1-2 dislocation. Direct posterior open reduction was achieved by distracting the facets and rotating them in a counterclockwise direction. Care was taken to avoid direct or indirect injury to the vertebral arteries. Segmental C1-2 fusion was performed. Distraction with lateral extension injury possibly gives rise to this unique fracture dislocation. Preoperative imaging including angiography for vertebral arteries helps in defining the cause of fixity and in surgical planning. Direct posterior reduction is possible in such fixed C1-2 lateral dislocation, circumventing transoral surgery-provided the facets are preserved.