Page 668 - Adams and Stashak's Lameness in Horses, 7th Edition

634 Chapter 5

was 3 years, and 28 of 54 (52%) were less than 6 months
of age. 14
VetBooks.ir complete, open or closed, simple or comminuted, and
Humeral fractures are classified as incomplete or
nondisplaced or displaced. Most are complete, closed,
and displaced. Comminution occurs occasionally.
Humeral fractures can also be classified by location:
proximal humeral head (epiphysis and metaphysis in
foals), greater tubercle, deltoid tuberosity, mid‐diaphy-
seal, distal metaphyseal and epiphyseal, and distal con-
dylar and epicondylar (Figures 5.41 and 5.42). 14,25,60,66,83,94
Most fractures are reported to involve the middle third
of the diaphysis, either oblique or transverse or spiral
configuration and almost never open (Figure 5.42). 11,56
A study on 54 horses with humeral fractures reported
that 9 of 54 (17%) involved the physis (1 proximal and
8 distal), 8 of 54 (15%) occurred in the proximal meta-
physis (4 oblique and 4 transverse), 11 of 54 (20.4%)
were distal metaphyseal fractures, 26 of 54 (48%) were
diaphyseal (2 short oblique, 4 transverse, 20 long
oblique or spiral), and 1 of 54 was open. In another
14
study done on 22 horses with humeral fractures, 14 of
22 fractures were spiral in configuration. Uncommonly
96
foals will sustain multiple fractures involving the elbow
region. 6,62 Fractures of the greater tubercle can involve
either the caudal or cranial aspect 83,94 and occasionally
are comminuted. 60
Because of the large muscular attachments to the
humerus, there is often considerable overriding with dis- Figure 5.41. Proximal metaphyseal transverse humeral fracture.
placed fractures (the distal fragment being displaced Source: Courtesy of Dr. Martin Waselau.

A B
Figure 5.42. (A) An oblique lateral view of a spiral nonarticular fracture of the midhumerus. (B) Lateral view of a healing spiral nonarticu-
lar fracture of the midhumerus treated conservatively for 5 months. Source: Courtesy of Dr. Gary Baxter.