US Department of Defense
BLAST INJURY RESEARCH
COORDINATING OFFICE
Advancing Blast Injury Research to Protect and Heal Those Who Serve

What other injuries are associated with blast-related, dismounted single-leg amputation?


The weapons of choice used by insurgents in the recent war in Afghanistan are improvised explosive devices (IEDs); with most patrols done on foot, this leads to a pattern of injuries associated with lower limb amputation, called "dismounted complex blast injury" (DCBI). The purpose of this study was to better define and describe the injuries happening to the non-amputated leg in patients injured as the result of DCBI. A better defined pattern of injury can alert trauma surgeons and medics to disseminated injuries elsewhere, informing treatment and securing better outcomes for Service members and their Families.

This study involved a review of past cases from the United States and United Kingdom Joint Theater Trauma Registries of injuries resulting from IEDs. Computed tomography and x-rays were used to characterize the injuries. Various statistical methods were used to compare the data from different types of injuries by level of traumatic amputation – that is, amputation caused directly by the injury rather than by surgical intervention.

Of the 295 patients with leg injuries, 201 had traumatic leg amputations. All were male, with a mean age 23.38+/-3.77. The study finds that a little over half the traumatic amputations occurred below the knee and above the ankle, and about a quarter are through the knee, with the rest distributed above the knee, through the ankle, or in the hindfoot ("heel"). These amputations are commonly associated with fractures in the other foot, and the pattern of fractures seems different from that in patients with lower-leg injuries but without a traumatic amputation: whereas hindfoot fractures dominate in the latter population, ankle fractures seem most common among amputees. Single-leg traumatic amputation in this cohort is also associated with changes in upper-limb injuries: above-the-knee amputations in particular are significantly associated with hand and wrist fractures in both arms, and with finger fractures in the hand on the side without the amputation. Consistently with other studies, they found an association between leg amputations and urogenital injuries, suggesting that patients with leg amputations should be examined for such wounds. None of the single-leg amputees suffered spinal injuries, and only 2% of all the dismounted injuries suffered spinal injuries, even though a previous study of vehicular injuries found a strong association between heel fractures and spinal injuries – again suggesting particular features of this patient population.

This study is a necessary first step in describing dismounted traumatic blast amputation pathophysiology. It can guide data collection for further, prospective studies, alert forward-deployed medical care facilities to potential patterns of injury, guide training, tactics and procedures for dismounted operations, and guide the development of personal protective equipment for dismounted operations.


Publication:

Dupaix JP, Wilding SR, Tubb CC, Oh JS, and Ryan PM. (2018) "Second Place: Dismounted complex blast injuries: patterns of remaining limb injuries in patient with single-limb lower extremity amputations." Current Orthopaedic Practice 29(4): pp. 297-301.

Last modified: 12-Sep-2018