Spontaneous Chalk-Stick Fracture in Ankylosing Spondylitis: A Case Report.

Ankylosing spondylitis (AS) is an inflammatory disease affecting mainly the sacroiliac joints and the spine. In long-standing disease, the fused spine of AS patients is susceptible to spinal fractures, even after low impact trauma. We present a 61-year-old man with long-standing AS who presented with anterior and posterior longitudinal ligament rupture and T12 and L1 vertebral endplates fractures (a so called "chalk-stick fracture") without reporting any prior trauma and discuss relevant issues.