Prevertebral Soft-Tissue Swelling at C7 Is Highly Sensitive for Cervical Spine Ligamentous Injury Study Type: Retrospective Cohort Study.

Unlabelled: To determine the diagnostic potential of prevertebral soft-tissue (PVST) swelling in cervical spine ligamentous injury (LI).

Background: PVST swelling in the cervical spine is a historical indicator of cervical spine injury; however, at present, there are no limited objective criteria to use PVST swelling to guide clinical decision-making regarding cervical spine LI. This study investigates PVST thickness as a screening measure for cervical spine LI with a potential to identify indications for advanced imaging.

Methods: The registry at an urban level 1 trauma center was queried for cervical spine injuries between 2010 and 2016. Twenty-nine patients with LIs who had both CT and MRI available were included. Fifty-nine patients with bony injury (BI) were also included, and 99 patients undergoing CT of the cervical spine after blunt trauma without evidence of cervical spine injury were included as control patients.

Results: PVST swelling >11.5 mm at C7 was 89.7% sensitive (72.7% to 97.8%) and 51.5% specific (41.3% to 61.7%) for LI. In men, a PVST thickness of 11.5 mm at C7 was 96% sensitive (79.7% to 99.9%) and 46.2% specific (32.2% to 60.5%) for LI. Patients with LI were more likely to be men (86.2% versus 52.5% control, < 0.01). 86.2% of patients with LI (25 of 29) had associated BI. Patients who had LI and no associated BI (n = 4) were all men, and all had PVST thickness >11.5 mm at C7 (avg. PVST 17.7 mm ± 2.5).

Conclusion: C7 PVST thickness >11.5 mm was highly sensitive but poorly specific for cervical spine LI. This threshold may represent an appropriate PVST thickness to rule out LI because patients with PVST ≤11.5 mm are unlikely to have cervical spine LI and may not benefit from MRI.