The blast pelvis

Decreasing the human cost of war is a vital role within the Ministry of Defence, and the Defence Medical Services. With the considerable improvements in care, from point of wounding to rehabilitation, it is possible that we have reached the ceiling of optimal management with available, deployed resources. Injury prevention or mitigation may therefore have a more important role than ever in improving survival rates. The current character of conflict, and certainly the recent conflicts in Iraq and Afghanistan have seen the Improvised Explosive Device used to devastating effect to personnel. These devices cause multisystem injuries, and have a high fatality. The lower extremity was most often affected in these recent conflicts, and many fatalities occurred. A greater understanding of lower extremity trauma biomechanics is likely to be key to preventing future fatalities due to injuries in this body region. This thesis focusses on lower extremity blast injury, performs a review of current understanding, and undertakes a casualty data analysis to further understand injury patterns and the cause of fatal wounding. This analysis finds that haemorrhage secondary to pelvic fracture is the key factor in fatal lower extremity injuries, and therefore an area of considerable research interest. Pelvic injury patterns were therefore analysed using measurement techniques to qualify injury patterns and understand the link between injury patterns and the presence of vascular injury. Subsequent physical and computational testing provided a platform to apply different loading conditions to the pelvis to replicate a blast injury, and understand the behaviour of the bony structures under high rate axial loading. This thesis concludes that the anterior pelvic ring at the pubic symphysis is key to pelvic integrity at high rates of loading. Disruption of the anterior pelvis can lead to subsequent posterior ligamentous rupture which, due to the proximity to major vessels, can lead to major haemorrhage and death. Preventing lateral disruption may be the key to maintaining pelvic integrity at these high loading rates, and preventing vascular compromise and fatality from lower extremity blast injuries.