Prevertebral swelling in cervical spine injury: identification of ligament injury with magnetic resonance imaging.

In a retrospective analysis of 27 consecutive patients with acute cervical spine injury who underwent Magnetic Resonance (MR) Imaging, 14 had prevertebral soft tissue swelling on initial lateral radiographs, of whom 13 had anterior longitudinal ligament disruption on MR. Of the eight patients who had isolated prevertebral swelling in the absence of vertebral body fracture or significant subluxation, seven had anterior longitudinal ligament disruption shown on MR imaging. Of the patients with MR documented ligament injury, three had dynamic flexion-extension radiographs within 2 weeks of injury and all demonstrated cervical instability. As cervical prevertebral swelling following trauma was indicative of ligament injury in nearly half the patients, this finding should prompt clinical and radiographic follow-up to exclude spinal instability.