Biology Reference
In-Depth Information
fractures are usually clearly identifiable, where long linear radiating fractures travel away
from the area of impact, and are followed, given enough energy, by more circular concentric
fractures (see
Figure 8.3
). Since the injury inflicted with blunt trauma is a relatively slow
loading force (remember blunt force trauma is considered as occurring in miles per
hour), the bone takes a longer time to reach the failure or fracture point, and will display
a greater amount of plastic deformation. Also, if any areas of the skull are affected, there
may be areas of delamination, in which the inner and the outer table of bone have become
separated.
Ballistic Trauma
Ballistic trauma is also referred to as projectile trauma, and involves a much higher rate of
acceleration (rate of change of velocity over time) than blunt trauma. Ballistic trauma is
trauma sustained from any type of firearms or munitions. The speed of the impact as well
as the surface area of the projectile are the critical components that create the difference
between blunt and ballistic trauma fracture patterns. The most common types of ballistic
trauma involve projectiles fired from firearms, but explosions fit into this category as well.
The impact of the ballistic projectile into the bone often creates characteristic fracture patterns
of an entrance wound and exit wound. These defects represent the entry and exit of the
FIGURE 8.3
Concentric and radiating fractures in a cranial vault.
