Dens Fracture with Concurrent Subaxial Cervical Spine Injury in Patients with Ankylosing Spondylitis

Odontoid process fractures in patients with ankylosing spondylitis (AS) are rare and their finding together with subaxial cervical spine injury is a great exception. Neither the mechanism of such a combined cervical spine injury nor its surgical treatment has so far been reported in the relevant literature (MEDLINE). The authors present two such cases, one in a 30- and the other in a 74-year-old man. Both AS patients showed a common mechanism of injury sustained in a car accident, which involved hitting a solid barrier at 60 to 70 kilometres per hour, resulting in hyperextension of the cervical spine. In both patients the fractures were stabilised from the anterior approach: the dens fractures with one or two screws by the Magerl-Bahler method and the subaxial fractures with long-plate and screw fixation. At 2 post-operative years complete bone union of the subaxial spine was recorded in both patients; complete healing of the dens fracture was achieved in one patient while in the other partial fibrous union of the dens fracture occurred.