Second Place: Dismounted complex blast injuries: patterns of remaining limb injuries in patients with single-limb lower extremity amputations

Abstract

Background: The conflict tactic of the Afghanistan theater of operations utilizes blast weapons while most patrols are on foot, leading to a pattern of injuries associated with lower extremity amputation termed “dismounted complex blast injury” (DCBI). The purpose of this study was to better define and describe the injuries occurring to the nonamputated extremities in patients injured as the result of DCBI. Methods: A retrospective review was conducted of data from the United States and United Kingdom Joint Theater Trauma Registries of injuries resulting from a dismounted improvised explosive device (IED) blast. CT and radiographs were used to characterize injuries. Fisher’s exact test was used to compare categorical data, and binomial logistic regression was used to compare proportions of types of injuries by traumatic amputation level observed. Results: Of the 295 patients with lower extremity injuries, 201 had traumatic lower extremity amputations (140 with bilateral lower extremity and 61 with single-leg amputations). All were male, with a mean age 23.38+/-3.77. Below-knee amputation was most common (55.7%), followed by through-knee (25%), and least frequently through-ankle amputation. Hindfoot-level amputation was associated with an 8.1% increase in the odds of the presence of a skeletal foot injury in the nonamputated lower extremity. An association of above-knee amputation with bilateral distal upper extremity injury was found. There was a 10.9% increase in odds for the ipsilateral hand/wrist fracture given an AKA. Conclusions: Proximal lower extremity amputation levels are significantly associated with distal upper extremity skeletal injury. Hindfoot-level amputation is significantly associated with contralateral foot fractures. Amputation levels proximal to the ankle often presented with associated genitourinary injuries.