Characterization of spinal injuries sustained by American service members killed in Iraq and Afghanistan: a study of 2,089 instances of spine trauma.

BACKGROUND: This study sought to characterize spine injuries among soldiers killed in Iraq or Afghanistan whose autopsy results were stored by the Armed Forces Medical Examiner System.

METHODS: The Armed Forces Medical Examiner System data set was queried to identify American military personnel who sustained a spine injury in conjunction with wounds that resulted in death during deployment in Iraq or Afghanistan from 2003 to 2011. Demographic and injury-specific characteristics were abstracted for each individual identified. The raw incidence of spinal injuries was calculated and correlations were drawn between the presence of spinal trauma and military specialty, mechanism and manner of injury, and wounds in other body regions. Significant associations were also sought for specific injury patterns, including spinal cord injury, atlantooccipital injury, low lumbar vertebral fractures, and lumbosacral dissociation. Statistical calculations were performed using χ statistic, z test, t test with Satterthwaite correction, and multivariate logistic regression.

RESULTS: Among 5,424 deceased service members, 2,089 (38.5%) were found to have sustained at least one spinal injury. Sixty-seven percent of all fatalities with spinal injury were caused by explosion, while 15% occurred by gunshot. Spinal fracture was the most common type of injury (n = 2,328), while spinal dislocations occurred in 378, and vertebral column transection occurred in 223. Fifty-two percent sustained at least one cervical spine injury, and spinal cord injury occurred in 40%. Spinal cord injuries were more likely to occur as a result of gunshot (p < 0.001), while atlantooccipital injuries (p < 0.001) and low lumbar fractures (p = 0.01) were significantly higher among combat specialty soldiers. No significant association was identified between spinal injury risk and the periods 2003 to 2007 and 2008 to 2011, although atlantooccipital injuries and spinal cord injury were significantly reduced beginning in 2008 (p < 0.001).

CONCLUSION: The results of this study indicate that the incidence of spinal trauma in modern warfare seems to be higher than previously reported.

LEVEL OF EVIDENCE: Epidemiologic study, level III.