Impact of MRI on the management of CT-defined AO spine A/B thoracolumbar fractures.
OBJECTIVES To assess the added value of emergency spine MRI compared with CT alone in patients with AO Spine A/B thoracolumbar trauma without neurological deficit, focusing on clinical management. MATERIALS & METHODS This retrospective single-center study included consecutive trauma patients who underwent both CT and spine MRI between November 2023 and October 2025. CT served as the index test and MRI as the adjunct modality for fracture characterization and posterior ligamentous complex (PLC) assessment. MRI was performed according to an indication-driven institutional protocol. Changes in treatment strategy (conservative, minimally invasive, invasive) before versus after MRI were analyzed. Paired Wilcoxon signed-rank, McNemar, and symmetry tests were used as appropriate. Agreement was assessed using Cohen's κ. Predictors of MRI-driven management change were explored using Fisher's exact test and multivariable logistic regression. RESULTS A total of 158 patients were included (114 men; mean age, 35.8 ± 12.4 years; range 18-59). MRI detected a higher number of fractured vertebrae than CT (2.2 ± 1.8 vs. 1.5 ± 1.0; p < 0.001). MRI led to a change in treatment strategy in 19 patients (12%), predominantly reflecting escalation of care (p < 0.001). Management change was driven by MRI-detected PLC injury in 17 patients (partial in 8, complete in 9), by occult spinal cord injury without clinical translation in 2 patients, and by both mechanisms simultaneously in 4 patients. AO Spine fracture classification changed after MRI in 39 patients (25%), reflecting substantial overall agreement between MRI and CT (κ = 0.64; p < 0.001). MRI identified significantly more posterior ligamentous complex injuries (AO Spine type B) than CT when comparing fracture classification (48 vs. 16 patients; p < 0.001) and dedicated PLC status assessment (48 vs. 13 patients; p < 0.001). No CT-based variable remained independently associated with management change after adjustment. CONCLUSION In selected patients with neurologically intact thoracolumbar trauma, emergency spine MRI modified therapeutic management in 12% of cases, primarily by revealing posterior ligamentous complex injuries and occult spinal cord findings not apparent on CT. These results support an indication-driven rather than systematic use of MRI.