Bone fractures produced by high velocity impacts

Abstract

The effects of high velocity impact to the distal end of 122 human femurs were studied using one-quarter inch steel spheres as projectiles, with impact velocities from 500 to 1700 feet per second. In the lower velocity range, a “drill hole” fracture was produced with low energy expenditure, and the diameter of this type of fracture was increased as a function of increasing velocity. At the higher impact velocities the bone exploded with a violent radial displacement of the material surrounding the missile path, similar to the cavitation effect often seen in soft tissues. At increasing impact velocities, increasing amounts of energy were expended in producing the fracture.