A 60-year-old man with a history of ankylosing spondylitis presented to the emergency department with neck pain and paralysis of the arms and legs after a fall. During the previous 5 years, he had not received treatment for the ankylosing spondylitis. At presentation, the blood pressure was 80/40 mm Hg and the heart rate was 56 beats per minute. Findings on physical examination were consistent with acute compression of the lower cervical spinal cord. Vasopressors were infused to treat neurogenic shock, and bladder catheterization was performed to treat acute urinary retention. Computed tomography of the cervical spine showed fused vertebrae with a displaced fracture — also known as a chalk-stick fracture — at the level of C6–C7 (Panel A). Magnetic resonance imaging of the cervical spine confirmed spinal cord compression at that level (Panel B). Ankylosis of the vertebrae results in increased bone fragility and risk of pathologic fracture. Neck or back pain after even minor trauma should prompt cross-sectional imaging to evaluate for serious injury. Surgical decompression and fusion of the spine were performed. Postoperatively, the patient regained function of his upper limbs but died from pneumonia 5 weeks later.