The differentiation of traumatic and heat-related fractures in burned bone.

Interpretations of antemortem and perimortem trauma are complicated when dealing with cases involving extreme exposure to fire. This investigation attempts to discern the signatures of perimortem trauma from heat related trauma. Femora of domestic pig, sus scrofa, with minimal soft tissue and articulated patellae were subjected to varying traumatic forces. Skeletal elements were impacted with blunt and sharp forces, cut with varying instruments, subjected to torsional forces of shot. Bones were burned in various situations in conjunction with Knox County Rural/Metro Fire Department training exercises conducted in Knox County, Tennessee. Following recovery, fragments were subjected to radiographic, macroscopic, and microscopic analyses. Skeletal elements were reconstructed to permit accurate comparison with pre-fire visual records. In addition, fracture surfaces were examined under both transmitted light and scanning electron microscopy in an attempt to discern surface signatures of the causal fracture (trauma, heat, or situational). Results indicate that signatures of sharp force trauma remain evident following incineration. Furthermore, radiopaque spatter was not observed in any shot specimen. However, these initial findings suggest that the interpretation of blunt force and torsional trauma requires a rigorous examination and comparison of fracture patterns in conjunction with surface morphology.