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

Abstract

SummaryThe 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 exvivo 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.

Bending and torsional stiffness measurements of equine radii and tibiae

“…Each of our bones were fractured afterwards in a side impact test, see (Fürst et al 2008b, Piskoty et al 2012) and the two static properties could be used as characteristic strength values of these individual bones. During the evaluation phase of the whole program we tried to find cross-correlations between the various properties of the bones.…”

A review of equine tibial fractures

“…14 When subjected to the simulated kick in a modified three-point-bending trial, the degree of comminution was greater in tibial fractures as compared with radius fractures which the authors attributed to a difference in surface geometry between the equine tibia and radius. 14 Regardless of aetiology, complete tibial fracture typically manifests clinically as acute non-weightbearing lameness of the affected limb. 3 Diaphyseal fractures are associated with a high degree of soft tissue injury, and severe swelling and sensitivity of the overlying tissue is common.…”

“…Equine tibial fractures can be separated into broad aetiological classifications of impact and fatigue (Figure 2). 3,13 An impact fracture is the result of a single load acting on the bone that exceeds its maximum stress capacity 14 . The most common impact fractures in horses occur as a result of being kicked.…”

“…Of the complete fractures, the fracture configurations were most often oblique, transverse or oblique with a short transverse component 8 . In an ex vivo model of kick injury, simulated kicks to the tibia most commonly resulted in incomplete fractures with a butterfly configuration or incomplete longitudinal fractures 14 . When subjected to the simulated kick in a modified three‐point‐bending trial, the degree of comminution was greater in tibial fractures as compared with radius fractures which the authors attributed to a difference in surface geometry between the equine tibia and radius 14 …”

“…8 In an ex vivo model of kick injury, simulated kicks to the tibia most commonly resulted in incomplete fractures with a butterfly configuration or incomplete longitudinal fractures. 14 When subjected to the simulated kick in a modified three-point-bending trial, the degree of comminution was greater in tibial fractures as compared with radius fractures which the authors attributed to a difference in surface geometry between the equine tibia and radius. 14 Regardless of aetiology, complete tibial fracture typically manifests clinically as acute non-weightbearing lameness of the affected limb.…”