Completely dislocated hangman's fracture with a locked C2-3 facet. Case report.

The authors report a rare case of a hangman's fracture involving complete dislocation of C-2 onto C-3, accompanied by a C2-3 locked facet and asymptomatic bilateral vertebral artery injuries. The patient, a 25-year-old man who sustained a neck injury in an industrial accident, presented with a mild central spinal cord syndrome. His initial lateral cervical radiograph showed complete anterior dislocation of the C-2 body onto C-3, bilateral neural arch fractures, and a unilateral locked facet. The mechanism was likely flexion and compression. The grossly unstable spine and the locked facet were treated by posterior decompression, reduction, and C1-3 fixation. The patient recovered in several days and is without neurological deficit.