Association of concomitant subaxial cervical spine injury with imaging-based spinal cord injury and impaired consciousness in upper cervical spine trauma.

PURPOSE : To evaluate the association between concomitant subaxial cervical spine injury and imaging-based spinal cord injury (ISCI) in a Magnetic Resonance Imaging (MRI) selected cohort of patients with upper cervical spine trauma (UCST), and to assess its relationship with impaired consciousness (Glasgow Coma Scale [GCS] ≤ 8). METHODS : We performed a retrospective cohort study at a Level I trauma center. Adult patients (≥ 18 years) with UCST identified on baseline CT were included. Two blinded neuroradiologists (a senior board certified neuroradiologist and a neuroradiology fellow) independently recorded AO Spine Upper Cervical Classification System (UCCS) grades and MRI findings across the entire cervical spine. The primary outcome was ISCI, defined as intramedullary edema and/or hemorrhage on MRI. The secondary outcome was impaired consciousness (GCS ≤ 8). RESULTS : Of 443 screened patients, 165 met inclusion criteria. ISCI was present in 23/165 patients (13.9%). On univariate analysis, ISCI was associated with subaxial fractures, ligamentous injury, disc injury, and facet dislocation or subluxation (all p ≤ .05). On multivariable analysis, subaxial discoligamentous injury was independently associated with ISCI (odds ratio [OR], 3.63; 95% confidence interval [CI], 1.18–11.19; p = .0245). Impaired consciousness occurred in 58/165 patients (35.1%) and was independently associated with craniocervical junction dislocation (OR, 2.80; 95% CI, 1.14–6.87; p = .0244), an exploratory association given the multifactorial determinants of GCS in trauma. CONCLUSION : In this MRI selected UCST cohort, subaxial discoligamentous injury was independently associated with imaging based spinal cord injury, whereas impaired consciousness was more closely associated with craniocervical junction instability. These findings highlight the importance of comprehensive whole cervical spine evaluation in patients with UCST undergoing MRI.