Fracture of the odontoid peg in ankylosing spondylitis: case report

Fractures in patients with ankylosing spondylitis tend to affect the lower cervical spine. We describe a 50-year-old man who sustained fractures of the odontoid peg and body of the second cervical vertebra after a hyperextension injury. In absence of atlanto-occipital fusion, deformity from previous lower cervical spine injury may have contributed to susceptibility for this very rare combination of fractures. The patient was treated surgically with a good result.