Clinical update: gunshot wound ballistics

Abstract

Although firearm related injury and mortality actually may be declining, gunshot trauma remains a significant cause of morbidity and socioeconomic cost with 115,000 missile injuries annually and as many as 40,000 deaths. Wounds typically are classified as low-velocity (< 2000 feet/second) or high-velocity (> 2000 feet/second). However, these terms can be misleading. More important is the efficiency of energy transfer, which is dependent on the projectile's physical characteristics including deformation and fragmentation, kinetic energy, stability, entrance profile, path traveled through the body, and the biologic characteristics of the tissues. Therefore, the decision whether to explore the wound should not be based solely on the involvement of a high-velocity or low-velocity weapon. The majority of low-velocity gunshot wounds can be treated safely nonoperatively with local wound care and outpatient treatment. Treatment of associated fractures generally is dictated by the bony injuries, which have similar personalities to closed fractures. Because contamination is not always apparent, routine antibiotic prophylaxis still is recommended. The soft tissues assume a more crucial role in high-velocity and shotgun fractures, whereas high-energy injuries and grossly contaminated wounds mandate irrigation, appropriate debridement, and the use of open fracture protocols. However, a patient with a high-velocity wound with limited soft tissue disruption, no significant functional deficits, no evidence of bullet fragmentation, and minimal bony involvement can be a candidate for simple wound care. When exploration is indicated, decompression and excision of necrotic tissue is the rule with color, consistency, contractility, and capacity to bleed providing valuable information regarding muscle viability.