Stuart Edward Mirvis MD, Abstract Co-Author: Nothing to Disclose

Wilbur Chang MD, PhD, Presenter: Nothing to Disclose

To determine CT signs that can diagnose subtle craniocervical distraction injuries (CCDI).

The study population consisted of 50 control blunt trauma patients without cervical spine injury (Group 1) and 30 patients identified retrospectively from a Trauma Radiology data base diagnosed with CCDI from 2000-2006. Findings were assessed using coronal and sagittal reformatted cervical spine CT images using electronic caliper measurements. Measures included the C0-C1 and C1-C2 spinolaminar line separation, the basion-odontoid tip distance, the basion-posterior axis line distance, the height of the anterior axis above the odontoid tip, the summed condylar-C1 separations, and the atlanto-dental space. Statistical analysis comparing control and injury groups was performed utilizing the 95% confidence interval and the Wilcoxon two-sample test for statistical significance.

The data revealed several parameters that significantly and independently correlated with CCDI. Using the 95% confidence interval definition, these included a C1-C2 spinolaminar separation of >7.8 mm (p=0.02), a basion to posterior axial line > 6mm (p=0.0007), and a summed condyle-C1 separation of >4.3mm (p=0.001). The atlanto-dental space, basion-odontoid tip distance, and the vertical elevation of the anterior axis ring above the odontoid tip were not statistically different between the two groups. A “V”-shaped atlanto-dental space was predictive of this injury.

This retrospective study determined several measured parameters that statistically distinguish CCDI from normal patients over a range of injury severity using CT multiplanar reformations. These parameters have not been previously established and supplement plain radiographic observations. Some cases of CCDI are quite subtle, yet clinically highly important and may not demonstrate the abnormal imaging findings that have heretofore been reported.

The study establishes statistically significant CT-based measurements to identify craniocervical distraction injuries that may not be identified based on current imaging criteria.

Mirvis, S, Chang, W, Diagnostic CT Determinants of Cervicocranial Distraction Injury.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4441679.html