Traumatic atlanto-axial subluxation.

Traumatic atlanto-axial subluxation is a rare injury which may not be revealed on routine radiographs, especially when there is muscle spasm. We report on seven patients with atlanto-axial subluxation as a result of neck injury; only two of them had significant head injuries. Three patients presented with a neurological deficit attributable to the injury, one immediate and two with delayed onset. Traumatic atlanto-axial instability, occurring in an otherwise healthy patient, has a potential for neurological disaster; early consideration of operative treatment is indicated.