Abstract
Improvised Explosive Device (IED) attacks on vehicles have been a significant feature of recent conflicts. The Dynamic Response Index (DRI), developed for predicting spinal injury in aircraft ejection, has been adopted for testing vehicles in underbelly blast. Recent papers suggest that DRI is not accurate in blast conditions. We suggest that the distribution of blast and ejection injuries is different.
A literature review identified the distribution of spinal fractures in aircraft ejection incidents. A Joint Theatre Trauma Registry search identified victims of mounted IED blast with spinal fractures. The distribution of injuries in the two groups was compared using the Kruskall Wallis test.
329 fractures were identified in ejector seat incidents; 1% cervical, 84% thoracic and 16% lumbar. 245 fractures were identified in victims of mounted blast; 16% cervical, 34% thoracic and 50% lumbar. There was no significant similarity between the two (p=1). There was no statistically significant difference between the distribution of fractures in blast survivors versus fatalities.
The difference between blast and ejection injury patterns suggests that injury prediction models for ejection should not be extrapolated to blast mechanisms and that new models need to be developed.
