Fragile yet rigid: surgical management of vertebral fractures in ankylosing spondylitis—a five-case series and literature review

Abstract

Ankylosing spondylitis (AS) converts the spine into a rigid, osteoporotic structure susceptible to three-column fractures from trivial trauma, with disproportionately high risks of neurological injury, missed diagnosis, and perioperative death. To describe the presentation, classification, surgical management, and outcomes of five patients with AS-related spinal fractures, and to review the relevant literature. In this retrospective case series, five consecutive patients with AS (modified New York criteria) sustaining acute traumatic spinal fractures (one cervical, four thoracolumbar) between 2018 and 2021 underwent posterior instrumented fixation. Construct length was individualized according to fracture level, neurological status, and need for decompression. Radiological and clinical outcomes were assessed by two independent observers (ICC > 0.85, 95% CI). Mean age was 54.6 years (range 49–60); mean AS duration 12 years (range 7–15). All five fractures were AO Spine Type C. Diagnosis was delayed in two patients. Four patients achieved significant neurological recovery (ASIA B/C → E) or maintained intact neurology (ASIA E), with solid fusion (Bridwell grade 1), intact implants, and meaningful improvement in VAS and ODI at a mean follow-up of 4.5 years (median 4.5 years; range 4–5 years), whereas one patient with complete (ASIA A) spinal cord injury and respiratory compromise died postoperatively from cardiac arrest approximately three hours after surgery. Posterior stabilization achieves favorable neurological and functional outcomes in AS patients with incomplete or absent deficits. Construct length should be individualized: extended multilevel instrumentation is standard when decompression is required, while shorter tension-band constructs may be appropriate in selected neurologically intact patients with preserved posterior column integrity. Complete neurological injury with respiratory compromise carries high perioperative mortality risk requiring frank prognostic counseling. Not applicable.