Abstract
The biomechanics of civilian fractures have been extensively studied with a view to defining the forces responsible e.g. bending, torsion, compression and crushing. Little equivalent work has been carried out on military fractures, although fractures from gunshot can be divided into direct and indirect. Given that the effects of blast can be sub-divided into primary, secondary, tertiary and quaternary, the aim of this study was to try to determine which effects of the blast are responsible for the bony injury. This may have implications for management and prognosis as well as prevention.
We reviewed emergency department records, case notes, and all radiographs of patients admitted to the British military hospital in Afghanistan over a 6 month period (Apr 08–Sept 08) to identify any fracture caused by an explosive mechanism. In addition we reviewed all relevant radiographs from the same period at the Royal Hospital Haslar, who report all radiographs taken, and keep a copy of the images. Early in the study it became clear that due to the complexity of some of the injuries it was inappropriate to consider bones separately and we used the term ‘fracture zone’ to identify separate areas of injury, which could involve from 1 – 28 bones. It also became clear that the pattern of injury differed considerably between patients in open ground, and those in houses or vehicles. These 2 groups were considered separately and compared.
We identified 86 patients with fractures. The 86 patients had 153 separate fracture zones (range 1–6). 56 casualties in the open sustained 87 fracture zones (mean 1.55 fracture zones per casualty). 30 casualties in a vehicle or other cover sustained 66 fracture zones (2.2 per casualty). Of the casualties in the open, 17 fracture zones were due the primary effects of blast, 10 a combination of primary and secondary effects, 30 due to secondary effects and 30 from the tertiary effects of blast. Of the casualties in vehicles we could not identify anyone with a fracture due to either the primary or secondary effects of blast, all 66 fracture zones appeared to be due to the tertiary effects.
In both groups there appeared to be a significant number of fractures, often with no break in the skin, caused by severe axial loading of the limb. This was possibly due to the casualty impacting against the ground, building or the inside of a vehicle, and this is a group of injuries we are now studying in greater detail.
The abstracts were prepared by Major N. J. Ward ramc. Correspondence should be addressed to him at nickjward72@hotmail.com
