The Use of Dermestidae in Documenting Underbody Blast Injuries to Foot-Ankle-Leg Complex

Abstract

Conflicts in the Gulf have exposed warfighters to injury by means of improvised explosive device (IED) detonation beneath armored military vehicles, commonly referred to as underbody blast (UBB). Together with the pelvis, injuries to the foot-ankle-leg number among those most commonly sustained by warfighters in the event of a UBB. Multiple biomechanical tests are currently being conducted in order to develop injury thresholds and risk functions for warfighters subjected to these vertical loads. In a previous study of 38 foot-ankle-leg complexes tested under automotive and UBB load rates, a distribution of injuries was produced. High-speed x-ray video and post-test CT, Statscan (Lodox, Johannesburg, South Africa), and dissection were performed to document injuries. It is, however, difficult to thoroughly remove soft tissue and cartilage from the calcaneus and talus without inducing damage that could be mistaken as a test-induced injury. For this test series, Dermestidae macerated 31 tali and 18 calcanei revealing 12 and 4 injuries, respectively, that were previously undiagnosed through more traditional techniques. Logistic regressions were produced to quantify the significance of the findings. The pre- and post-maceration regressions predicted a 50% injury risk of 6626N and 4228N, respectively, or a 44% difference in mean.