Identifying Spinal Injury Patterns in Underbody Blast to Develop Mechanistic Hypotheses.

STUDY DESIGN A retrospective case series of UK victims of blast injury. OBJECTIVE To identify the injury patterns in the spine caused by under-vehicle blast, and attempt to derive the mechanism of those injuries. SUMMARY OF BACKGROUND DATA The Improvised Explosive Device has been a feature of recent conflicts with frequent attacks on vehicles, leading to devastating injuries. Vehicle design has evolved to reduce the risk of injury to occupants in underbody blast, where the device detonates beneath the vehicle. The mechanism of spinal injury in such attacks is not well understood; understanding the injury mechanism is necessary to produce evidence-based mitigation strategies. METHODS A Joint Theatre Trauma Registry search identified UK victims of blast between 2008 and 2013. Each victim had their initial scan reviewed to classify spinal fractures. RESULTS Seventy-eight victims were identified, of whom 53 were survivors. There were a total of 284 fractures, including 101 thoracolumbar vertebral body fractures and 39 cervical spine fractures. Most thoracolumbar fractures were wedge compression injuries. Most cervical spine fractures were compression-extension injuries.The most common thoracic and lumbar body fractures in this group suggest a flexed posture at the time of injury. Most cervical spine fractures were in extension, which might be compatible with the head having struck another object. CONCLUSION Modifying the seated posture might reduce the risk of thoracolumbar injury, or allow the resulting injury patterns to be controlled. Cervical spine injuries might be mitigated by changing vehicle design to protect the head. LEVEL OF EVIDENCE N/A.