In addition, Smith et al. They argue that radiating fractures associated with entrance defects are longer and are not arrested by preexisting fractures. Entrance and exit defects to extremities Detection of gunshot trauma on long bones and especially irregular bones can be a much more difficult process. Smaller bones, cancellous bone, and bone affected by degenerative diseases can shatter on impact, bearing little resemblance to the typical trauma site. In such cases where damage from a bullet is suspected, radiographs taken of the area can confirm the existence of radio-opaque particles left by the slug's path.
Entrance defect in a distal femur resembling a drill hole.
They observed that metaphyseal and diaphyseal fracture patterns differed greatly. Projectile trauma to the diaphyses in cadaver specimens differed from dry bone specimens in that there were numerous fractures surrounding the exit with little or no fragmentation around the exit in dry bone. William Wood and Company, 1916. Because the distal end is mostly composed of cancellous bone with only a thin layer of cortical bone the kinetic energy is better able to dissipate within the spongy area. This produces less destruction than in more compact cortical bone found in diaphyses which generate more deformation.