Multilevel spinal fractures in ankylosing spondylitis: illustrative case.

backgroundAnkylosing spondylitis (AS) is a chronic inflammatory disease marked by spinal rigidity, which predisposes patients to unstable fractures even after minor trauma. While isolated spinal fractures in AS are well described, multilevel fractures across the cervical, thoracic, and lumbar spine following a single traumatic event are exceedingly rare and pose substantial diagnostic and surgical challenges. OBSERVATIONS: The authors present the case of a 41-year-old male with advanced AS and a history of alcohol use and diabetes who sustained six unstable spinal fractures spanning the cervical, thoracic, and lumbar regions after a motor vehicle accident. The surgical intervention involved staged posterior spinal fusion (C3-T7, L2-S2 with pelvic extension), open reduction and internal fixation (C6-7, T2-3, L4), and laminectomy (T2-3). Neuronavigation and intraoperative fluoroscopy guided precise instrumentation. The patient had no postoperative neurological deficits and was discharged with a comprehensive postoperative care plan, including physical therapy and follow-up imaging. LESSONS: This case underscores the importance of high clinical suspicion and early imaging in AS patients with trauma, given their high risk for occult spinal fractures. Posterior-only surgical approaches can provide effective stabilization in complex multilevel injuries, especially in patients with comorbidities that preclude anterior exposure. https://thejns.org/doi/10.3171/CASE25236.