Spinal cord injury and spinal fracture in patients with ankylosing spondylitis

Background: Spinal cord injury (SCI) and spinal fracture are major complications in patients with ankylosing spondylitis (AS) who sustain spinal trauma. The purpose of this study was to investigate the incidence, predictors, and sequelae of spinal trauma in patients with AS. Methods: This retrospective study included patients with AS who were admitted for spinal trauma between January 1, 2006, and June 30, 2016. The study compared clinical outcomes of patients between group 1: SCI alone, group 2: spinal fracture alone (no SCI), and group 3: both SCI and spinal fracture. Results: Of the 6285 patients with AS admitted during the retrospective study period, only 105 suffered from spinal trauma and were enrolled in the study. Case number in group 1, 2, and 3 was 11(10.48%), 45(42.85%), and 49(46.67%), respectively. Among the patients with spinal fractures, 52.1% had SCI. Bamboo spine was significantly more prevalent in the fracture group than in the nonfracture group (78.7% vs. 36.4%; P = 0.006). Patients with SCI had more instances of subluxation or dislocation (48.3% vs. 8.9%; P < 0.001) and more cases of spinal epidural hematoma (SEH; 21.7% vs. 2.2%; P = 0.003) than patients without SCI. The rate of delayed diagnosis for spinal fracture was 31.4%, with one-third of patients developing delayed SCI. Among the patients with incomplete SCI, 58.3% achieved neurological improvement after treatment (P = 0.004). Conclusions: Patients with AS and bamboo spine at radiograph had a higher rate of spinal fracture, which may be an important factor in SCI in patients with AS. Spinal fractures involving the C3–C7 region, subluxation or dislocation, severe spinal fracture, and SEH were found to be predictive of SCI, and SCI in patients with AS resulted in higher mortality and complication rates.