Page 205 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

180 CHAPTER 1

VetBooks.ir 1.345 horses through the original physis and generally
avulse due to the attachment of the biceps brachii.

Clinical presentation
Affected horses are usually moderately-severely lame
and may lose function of the stay apparatus, there-
fore confusing the presentation with an ulna fracture
or radial neuropathy. Horses may show evidence of
a wound or external trauma (Fig. 1.345). Moderate
swelling is usually present and pain/crepitus is demon-
strated on palpation. Chronic fractures involving the
neck of the scapula may show neurogenic atrophy of
the supraspinatus/infraspinatus muscles due to dam-
age to the suprascapular nerve (Fig. 1.346). Stress
fractures may be bilateral and present as lameness with
pain on direct palpation in some cases. Complete stress
fracture will present as an acute-onset severe lameness.

Differential diagnosis
Humeral fracture; synovial sepsis; luxation; radial or
suprascapular neuropathy or brachial plexus injury.
Fig. 1.345 Supra- and infraspinatus muscle atrophy
in an Arab stallion that was kicked on the point of the Diagnosis
right shoulder while covering a mare and developed Diagnosis is often confirmed radiographically,
a suprascapular nerve paralysis. (Photo courtesy although evaluation of the body and spine of the
Graham Munroe) scapula can be difficult. Nuclear scintigraphy will
show increased radiopharmaceutical uptake in the

1.346 1.347

Figs. 1.346, 1.347 Photograph (1.346) of a discharging tract over the distal spine of the scapula following
a kick injury. Ultrasonography (1.347) shows irregularity and bone fragmentation consistent with a fracture.
A 6 cm section of bone was removed under standing sedation and local anaesthesia.