Ankylosing spondylitis (AS) is a progressive
multisystem chronic inflammatory disorder. The hallmark of this pathological
process is a progressive fusion of the zygapophyseal joints and
disc spaces of the axial skeleton, leading to a rigid kyphotic deformity
and positive sagittal balance. The ankylosed spine is unable to
accommodate normal mechanical forces, rendering it brittle and susceptible
to injury. Traumatic hyperextension injury of the cervical spine
leading to atlantoaxial subluxation (AAS) in AS patients can often
be fatal. We report a non-traumatic mechanism of injury in AS progressing
to AAS attributable to persistent hyperextension, which resulted
in fatal migration of C2 through the foramen magnum. Cite this article: