Page 657 - Adams and Stashak's Lameness in Horses, 7th Edition

Lameness of the Proximal Limb 623

THE ANTEBRACHIUM, ELBOW, AND HUMERUS

VetBooks.ir Jeremy hubert

FRACTURES OF THE RADIUS Etiology

In an original retrospective study of radial fracture con- Radial fractures usually result from a high‐impact
figurations, comminuted fractures were most common (21 blunt trauma such as a kick from another horse. A con-
of 47), followed by oblique fractures (12 of 47), transverse trolled postmortem study to evaluate fracture configura-
fractures (7 of 47), and physeal fractures (7 of 47). Open tions of the radius after a simulated kick on the medial
fractures usually involve the medial surface of the antebra- aspect of the radius resulted in the majority of the bones
chium, where there is minimal soft tissue coverage sustaining a fissure fracture (incomplete fracture) that
(Figures 5.24–5.26) A more recent study of 54 cases of ran longitudinally along the diaphysis. The next most
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radial fractures reported that 24% were open and commi- common configuration was an oblique fracture, some-
nuted, 26% were incomplete or fissure fractures, and 50% times with a fissure component, followed by a butterfly
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were deemed repairable as oblique (10), transverse (7), fragment fracture. The medial aspect of the bone was
Salter–Harris type II (5), spiral (3), and combined fractures chosen in the postmortem study to emulate the more
of the radius and ulna. Incomplete or fissure fractures are common finding of a kick to the medial side; a smaller
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relatively common fractures of the radius; the majority of retrospective study of radial fractures revealed the
which occurred along the longitudinal plane. Other
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uncommon radial fractures include stress fractures and
smaller articular fractures involving either the proximal or
distal articulation. Radial stress fractures compose a
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small percentage of reported stress fractures. In a recent
study of stress fractures in a racing Thoroughbred popula-
tion, only 4.3% of stress fractures involved the radius. 53

Figure 5.24. A complete oblique fracture of the radius extending Figure 5.25. A cranial to caudal view of a distal diaphyseal
from the mid‐diaphysis to the metaphysis. Source: Courtesy of comminuted fracture of the radius. Source: Courtesy of Dr. Martin
Dr. Andrew Lewis. Waselau.