Utility of Magnetic Resonance Imaging for Ligamentous Injury in Cervical Spine Trauma: A 2-Year Consecutive Case Cohort

Abstract

Magnetic resonance imaging (MRI) is increasingly used as an adjunct to spinal soft tissue evaluation in cervical spine (C-spine) trauma; however, the utility of this information remains controversial. In this consecutive observational study, we reviewed the utility of MRI in patients with C-spine trauma. We identified patients in real time over a 2-year period as they presented to our level 1 trauma center for C-spine computed tomography (CT) scan followed by MRI. MRI was obtained by the trauma team prior to the spine service consultation if (1) they were unable to clear the C-spine according to protocol or (2) if the on-call radiologist reported a concern for ligamentous integrity from the CT findings. Thirty-three patients, including 19 males (58%) and 14 females, with a mean age of 54 years, were referred to the spine service for concerns of ligamentous instability. The most common mechanisms of injury were motor vehicle accidents (n= 13) and falls (n= 11). MRI demonstrated ligamentous signal change identified by the radiologist as potentially unstable in all patients. Fifteen patients (45%) had multiple C-spine ligaments affected. The interspinous ligament was involved most frequently (28%), followed by the ligamentum flavum (21%) and supraspinous ligament (15%). All patients underwent dynamic upright C-spine X-rays that were interpreted by both the ordering surgeon and radiologist. There was no evidence of instability in any patient; concurrence between X-ray interpretation was 100%. The cervical collar was successfully removed in all cases. No patients required late surgical intervention, and there were no return visits to the emergency department of a spinal nature. MRI signal change within the ligaments of the C-spine should be interpreted with caution in the setting of trauma. To physicians less familiar with spinal biomechanics, MRI findings may be perceived in an inadvertently alarming manner. Bony alignment and, when indicated, dynamic upright X-rays remain the gold standard for evaluating the ligamentous integrity of the C-spine.