“…13,26,27 As a result, fractures can occur in any region of the spine, 11,12,17,26,28,29 and may be unstable if they occur in the lower cervical spine. 9,10,18,19,[30][31][32] In patients with AS, cervical spinerelated injury is largely attributed to traumatic hyperextension resulting from a fall or other accidental mechanism 9,10,18,19,30-32 but there are some reports suggesting the development of AAS in AS. 22,23 In 1979, Sorin et al 23 first described two cases with AAS as an early complication of AS.…”