Page 580 - Adams and Stashak's Lameness in Horses, 7th Edition

546 Chapter 4

amenable to treatment. Desmitis of the SL and DSLs If an incomplete sesamoid bone fracture is suspected,
may occur concurrently with fractured sesamoids. repeat radiographs should be taken after a period of 2–4
VetBooks.ir keep up with the dam is common for young foals under formed. This permits better evaluation of the fracture
weeks of stall rest, or nuclear scintigraphy can be per-
A history of galloping to exhaustion in an attempt to
line because it allows sufficient time for lysis/remodeling
2 months of age that have sustained fractures of their
sesamoid bones. 32,44,74 These fractures often occur in of the bone to occur. It should be emphasized that if
foals that have been confined to a box stall for several these horses are allowed to exercise, they run a great risk
days and then turned out for free exercise with the dam. of distracting the fracture and worsening the prognosis.
Ultrasonography should be performed on all apical and
Diagnosis abaxial fractures to identify the degree of concurrent
injury to the SL.
Diagnosis is based on the physical examination find-
ings described and confirmed with radiologic examina-
tion of the affected fetlock. If a fetlock joint is severely Treatment
swollen and the horse shows pain when pressure is The treatment of sesamoid bone fractures is based on
applied over the sesamoid bone(s), radiographs should the location of the fracture and the intended use of the
be taken to rule out the possibility of fracture. Cases of animal. Treatments include stall rest, cast application,
tenosynovitis also should be radiographed to eliminate surgical removal, lag screw fixation, circumferential
the possibility of fractured sesamoid bones accompany- wiring, and bone grafting.
ing this condition. Sesamoiditis may cause similar signs, Most fractures that are treated conservatively heal by
but radiographs do not demonstrate a fracture, and joint a weak fibrous union, and the fracture line can be
effusion is not a prominent feature of sesamoiditis. observed on radiographic examination for prolonged
Standard radiographic views should include the dor- periods of time. A portion of these fractures that have
sopalmar (DP), lateromedial (LM), and oblique projec- apparently healed will separate at a later date and result
tions. Occasionally the flexed LM may demonstrate in pain again. Generally, the conservative approach
lesions that are not detectable on the other standard pro- should be used for those horses that are not going to be
jections, and estimation of reduction potential of mid- used for performance in the future and in young foals
body fractures can be made. The addition of the skyline without distraction of fracture fragments. Surgical treat-
projection of the abaxial surface of the sesamoid bone is ment of sesamoid bone fractures in horses intended for
helpful in some cases to identify the exact location of performance is preferred for the most rapid return to
fractures on the abaxial surface (Figure 4.128). The performance with the least risk of future OA or sesa-
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radiographs should be closely examined for any signs of moid re‐injury. Surgical removal or stabilization to pro-
OA associated with the fetlock and incomplete fractures mote earlier bony union reduces the risk of secondary
that may be confused with enlarged vascular channels. OA and provides the best prognosis.

A B
Figure 4.128. (A) DP radiograph of a horse with an abaxial sesamoid fracture (arrow). (B) Skyline projection to highlight the abaxial
fragment of the sesamoid (arrow).