Cervical spinal cord injury without bony injury: A multicenter retrospective study of emergency and critical care centers in Japan

Background:. To demonstrate the clinical characteristics of patients with cervical cord injury (CCI) without bony injury in Japan. Methods: Retrospective review of 127 patients with CCI without bony injury treated between January 2003 and October 2005 at 11 institutions. Results: Prevalence of CCI without bony injury was 32.2% among all CCIs and 0.81 % among all blunt traumas. Mean age was 60.4 years (range, 19-90 years), with 104 patients (82%) >= 46 years old (older group). The major mechanism of injury among younger patients (< 46 years) was traffic injuries (39%), whereas minor falls (44%) predominated in older patients. High-energy mechanisms of injury were significantly more common for younger patients (35 % versus 15 %, p = 0.041). Mean injury severity score, abbreviated injury score for the head and Glasgow coma scale on admission were 17.2 +/- 4.7,0.6 +/- 0.9, and 14.2 +/- 2.1, respectively. Incomplete CCI occurred in 88.7%. On plain cervical spine radiography, spinal canal stenosis and spondylosis or ossification of the posterior longitudinal ligament were more frequent in older patients than in younger patients (43% vs. 13%, p = 0.008; 54% vs. 17%,p = 0.002, respectively). No abnormal findings were seen in 52% of younger patients. Conclusion: CCI without bony injury occurred more frequently in this study population than previously reported. Degenerative changes and spinal canal stenosis represent important risk factors for developing CCI without bony injury and the present results suggest that this injury may occur in younger adults during high-energy injuries in the absence of pre-existing cervical spine disease.