Traditional threshold for retropharyngeal soft-tissue swelling is poorly sensitive for the detection of cervical spine injury on computed tomography in adult trauma patients

STUDY DESIGN.: Retrospective cohort study. OBJECTIVE.: To examine the diagnostic value of prevertebral soft-tissue swelling in the setting of cervical spine trauma. SUMMARY OF BACKGROUND DATA.: In adult patients with trauma, an increase in the thickness of the retropharyngeal soft tissues is commonly used as a potential indicator of occult injury, but no studies have examined this parameter using computed tomography (CT) as a screening modality. METHODS.: A total of 541 patients with trauma with injuries at any level of the spine underwent CT. Patients with cervical injury were divided into those requiring noninvasive (observation or cervical collar, n = 142) management, and those requiring invasive (surgery or halo, n = 61) treatment. A control group of patients with isolated thoracic or lumbar injuries was used for comparison (n = 542). Retropharyngeal soft tissues were measured at the cranial and caudal endplates of all cervical levels on sagittal and axial CT. Sensitivity and specificity were calculated for +1, +2, and +3 standard deviations from mean values. RESULTS.: Sensitivity for detection of injury was found to be universally poor for all measurement groups. This ranged from 14.4% to 21.2% at +1 SD to 5.3% to 8.7% at +2 SD. Positive and negative predictive values for injury were also universally poor, ranging from 38% to 75%. Soft-tissue swelling as a sentinel sign of cervical spine injury demonstrates consistently high specificity and low sensitivity, precisely the opposite of what would be desired in a screening test. This study shows at best a sensitivity of 21.6% when using this parameter for the detection of these injuries in adult patients with trauma. CONCLUSION.: On the basis of the results of this study, we recommend against the routine use of measurement of the prevertebral soft tissues on CT as a screening tool for cervical spine injury in adult patients with trauma.