Page 238 - Adams and Stashak's Lameness in Horses, 7th Edition

204 Chapter 3

lesions, it will be used to illustrate the use of radiographic
signs or bone response patterns to arrive at a radiographic
VetBooks.ir inspection of the radiograph and is an important step in
diagnosis. Identifying radiographic signs requires close
accurately establishing a specific or differential diagnosis.
The following are radiographic signs manifested by
acute osteomyelitis:
• Soft tissue thickening adjacent to the bone is observed
as increased opacity, mottling, and obliteration of
adipose tissue in fascial planes.
• Periosteal new bone production. This new bone has
an irregular, indistinct border and parallels the bone
cortices. Subtle areas of subperiosteal bone lysis may
be seen in association with the acute periosteal bone
reaction. These changes are not usually seen until
7–10 days after clinical signs of the disease have been
observed. As the disease progresses, the periosteal
bone production parallels the cortex and spreads
proximal and distal from the original infection site.
• Permeative lysis is observed as small round lucent
areas, 2–3 mm in size, within cortical bone and may
extend into the medullary cavity. A moth‐eaten pat­
tern of lysis with larger lucent areas can also be seen
in acute and active aggressive lesions. These changes
are usually seen in association with acute periosteal
bone production.
• Areas of bone lysis within the physis, metaphysis, or
Figure 3.21. Dorsoproximal to palmarodistal oblique view of the epiphysis secondary to septic osteomyelitis in young
distal phalanx. Osteolysis and irregular margins of the collateral animals are very aggressive and mostly destructive,
ligament fossa (arrow) indicate resorptive enthesopathy. This finding giving little or no opportunity to the body to produce
was confirmed with magnetic resonance imaging. bone in the attempt to ward off the infection.

A

B

Figure 3.22. (A) Lateromedial (LM) and (B) dorsopalmar (DP) projections of a distal limb with rotating laminitis. Note the coarse trabecu­
lar pattern (more noticeable on distal P1 and proximal P2) secondary to disuse osteopenia from chronic non‐weight‐bearing.