Dynamic analysis of penetrating trauma.

BACKGROUND Whereas considerable literature exists on the wounding mechanics of high velocity projectiles in the military domain, there is a paucity of such data from projectiles routinely encountered in the civilian population in the United States. This study was undertaken to develop a methodology and to determine the dynamics of penetrating trauma secondary to low velocity projectiles (200-300 m/sec). To demonstrate the feasibility of the methodology and the experimental protocol, two markedly different projectiles were chosen in the study. METHODS Two projectiles were discharged into a human tissue simulant; one projectile was smooth and the other was of the expansion type. High-speed video photographic analysis and synchronized trigger techniques were used to describe the path of the projectile during its travel within the simulant. The temporal transient and residual profiles demonstrating the "wound involvement" were computed. RESULTS Results indicated a stark contrast between the two cases. There was a ratio of approximately three-to-one in the maximum wound involvement due to penetration. Transient wave oscillations during penetration and perforation of the projectile from the tissue simulant demonstrated significant differences in amplitudes and time durations. In addition, the residual wound involvement profiles indicated differences in the injury potential. CONCLUSIONS This study has provided an experimental methodology to delineate the temporal dynamic behavior of penetrating projectiles. To fully quantify and differentiate the dynamic differences in the temporal behaviors of the numerous available projectiles (with various combinations in design, type of equipment, and discharge), further research in this area is clearly necessary. The present protocol lends itself to be used to systematically analyze all these behaviors. Quantified data may assist clinical personnel in the management of penetrating trauma.