Background: For blunt trauma patients who have failed the NEXUS (National Emergency X-Radiography Utilization Study) low-risk criteria, the adequacy of computed tomography (CT) as the definitive imaging modality for clearance remains controversial. The purpose of this study was to prospectively evaluate the accuracy of CT for the detection of clinically significant cervical spine (C-spine) injury.
Methods: This was a prospective multicenter observational study (September 2013 to March 2015) at 18 North American trauma centers. All adult (≥18 years old) blunt trauma patients underwent a structured clinical examination. NEXUS failures underwent a CT of the C-spine with clinical follow-up to discharge. The primary outcome measure was sensitivity and specificity of CT for clinically significant injuries requiring surgical stabilization, halo, or cervical-thoracic orthotic placement using the criterion standard of final diagnosis at the time of discharge, incorporating all imaging and operative findings.
Results: Ten thousand seven hundred sixty-five patients met inclusion criteria, 489 (4.5%) were excluded (previous spinal instrumentation or outside hospital transfer); 10,276 patients (4,660 [45.3%] unevaluable/distracting injuries, 5,040 [49.0%] midline C-spine tenderness, 576 [5.6%] neurologic symptoms) were prospectively enrolled: mean age, 48.1 years (range, 18-110 years); systolic blood pressure 138 (SD, 26) mm Hg; median, Glasgow Coma Scale score, 15 (IQR, 14-15); Injury Severity Score, 9 (IQR, 4-16). Overall, 198 (1.9%) had a clinically significant C-spine injury requiring surgery (153 [1.5%]) or halo (25 [0.2%]) or cervical-thoracic orthotic placement (20 [0.2%]). The sensitivity and specificity for clinically significant injury were 98.5% and 91.0% with a negative predictive value of 99.97%. There were three (0.03%) false-negative CT scans that missed a clinically significant injury, all had a focal neurologic abnormality on their index clinical examination consistent with central cord syndrome, and two of three scans showed severe degenerative disease.
Conclusions: For patients requiring acute imaging for their C-spine after blunt trauma, CT was effective for ruling out clinically significant injury with a sensitivity of 98.5%. For patients with an abnormal neurologic examination as the trigger for imaging, there is a small but clinically significant incidence of a missed injury, and further imaging with magnetic resonance imaging is warranted.
Level of evidence: Diagnostic tests, level II.