The association between sagittal index, canal compromise, loss of vertebral body height, and severity of spinal cord injury in thoracolumbar burst fractures

Abstract

Aim: Our aim was to determine whether a combination of sagittal index (SI), canal compromise (CC), and loss of vertebral body height (LVBH) is associated with the severity of neurological injury in patients with thoracolumbar burst fractures. Materials and Methods: Seventy-four patients with thoracolumbar burst fracture undergoing instrumentation between 2010 and 2015 were analyzed retrospectively. The degree of neurological injury was determined using the American Spinal Injury Association (ASIA) scoring system. The association between the morphology of the fracture and the severity of neurological injury was analyzed. Results: There was a strong association between fracture morphology and the severity of neurological injury. Of the patients, 77.5% with SI ≥20°, 81.6% with CC ≥40%, and 100% with LVBH ≥50% had lesion according to ASIA. All of 7 patients with ASIA A had SI ≥20°, CC ≥40%, and LVBH ≥50%. On the other hand, 79% of the patients with ASIA E had SI <20°, 83.7% of the patients with ASIA E had CC <40%, and all of the patients with ASIA E had LVBH <50%. SI, CC, and LVBH were lower in neurologically intact patients (ASIA E), whereas they were higher in patients with neurological deficits (ASIA A, B, C, D) (P = 0.001; P< 0.01). These measurements had 100% negative predictive values and relatively high positive predictive values. Conclusion: SI, CC, and LVBH are significantly associated with the severity of neurological injury in patients with thoracolumbar burst fractures. The patients with SI >25°, the patients with CC >40%, and the patients with LVBH >50% are likely to have a more severe neurological injury.