Correlation Among Canal Compromise, Neurologic Deficit, and Injury Severity in Thoracolumbar Burst Fractures

In Brief Study Design. Review the association between injury severity, narrowing of the spinal canal, and neurologic deficit in thoracolumbar burst fractures. Objective. To determine which variable has a stronger association with neurologic deficit: spinal canal compromise or injury severity. Summary of Background Data. Literature has not reached a consensus regarding the cause of neurologic deficits in these fractures. Some believe it to be the spinal canal compromise and others the energy of trauma. Methods. A review of the clinical data and axial computerized tomography of 184 patients was performed. The injury severity was determined by subtracting neurologic data from the Injury Severity Score and New Injury Severity Score (ISSM and NISSM) to avoid the bias of overestimating neurologic lesions. Results. Patients with neurologic deficit presented higher canal compromise (52% vs. 34%), higher Injury Severity Score (24 vs. 11), New Injury Severity Score (26 vs. 13), ISSM (10 vs. 7), and NISSM (11 vs. 8, respectively). A positive correlation was found among these scores and the spinal canal compromise (P < 0.005; r < 0.35). In the current methodology, logistic regression proved narrowing of the spinal canal to be the only independent variable associated with neurologic deficit. Conclusions. Narrowing of the spinal canal has a stronger association with neurologic deficit than injury severity in thoracolumbar burst fractures. A cross-sectional study of 184 patients with thoracolumbar burst fractures treated between 1990 and 2004 revealed that the narrowing of the spinal canal is a stronger independent variable for establishing neurologic deficit than the injury severity gauged by the modified Injury Severity Score and New Injury Severity Score (subtracting the points for neurologic deficit).