Fracture configurations of the equine radius and tibia after a simulated kick.

The objective of this postmortem study was to determine the fracture configurations of the equine radius and tibia after a simulated kick. Fracture configurations of 35 radii and 36 tibiae from 19 adult horses were evaluated after a simulated kick in an experimental ex-vivo study. The bones were dissected, the proximal and distal ends were embedded in resin, fixed horizontally and preloaded in compression, and a steel impactor, designed to simulate a shod equine hoof, was dropped from a height of three to six metres onto the diaphysis. The experiments were filmed with a high-speed camera (30,000 pictures/second). The bones were then photographed and radiographed using a C-arm based 3D imaging device. A software programme (Osirix) was used to reconstruct the fissured and fractured bones three-dimensionally on a computer screen for assessment of the fracture configuration and fissure lines. Incomplete fractures occurred in 26 bones and complete fractures in 42. The complete fractures included 22 butterfly and 20 simple fractures; the latter included 17 oblique, two transverse and one longitudinal fracture. Additional longitudinal fissures occurred in 98% of the fractures. The butterfly fragment was always located on the side opposite the impact. There was a significant correlation between the type of bone and the fracture configuration: butterfly and oblique fractures occurred more frequently in the tibia, and incomplete fractures occurred more frequently in the radius. The data collected can be used to optimize evaluation of fractures and fissures caused by a kick and thereby improve surgical stabilization.