Analysis of risk factors affecting postoperative neurological recovery in patients with cervical spine fracture in ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic progressive inflammatory disease that mainly affects the spine and involves the sacroiliac and peripheral joints. Low-energy trauma can often lead to spinal fractures and spinal cord injuries (SCIs), the treatment of AS is challenging. The prognosis of neurological function in patients with AS cervical fracture and SCI is a major problem that must sought clinician attention on urgent basis. A total of 106 patients with AS cervical fractures who underwent surgical treatment at Shanghai Changzheng Hospital between August 2009 and 2021 were included in this study. All the patients were divided into 2 groups (improved group and the control group) based on their neurological function improvement at 1 year mark after the surgery. The baseline characteristics, perioperative factors, and procedural outcomes of all the patients including injury type, AS drug treatment, the injured segment, ossified anterior longitudinal ligament injury, spinal hypersignal, decompression time window, operation duration, blood loss, preoperative and postoperative American Spinal Injury Association (ASIA) score were recorded and analyzed. Among the 106 patients, 79 demonstrated improved neurological function at 1 year mark after the surgery. Binary univariate logistic regression analysis revealed significant differences in injury type (P = .018), ossified anterior longitudinal ligament injury (P = .01), operation duration (P = .002), spinal hypersignal (P = .001), preoperative ASIA score (P < .001), and prior AS drug treatment (P = .012). No significant differences were observed in the other variables (P > .05). Binary multivariate logistic regression analysis identified spinal hypersignal (OR = 37.185, P = .028), preoperative ASIA score (OR = 0.16, P = .012) and previous AS drug treatment (OR = 0.296, P = .049) as factors associated with postoperative neurological function improvement. The preoperative ASIA score and previous drug treatment of AS were identified as protective factors affecting the improvement of neurological functions in patients with AS cervical fracture after surgery. Preoperative T2-weighted spinal hypersignal was identified as an independent risk factor affecting the improvement of neurological function recovery in patients with AS cervical fracture after the surgery.