Page 761 - Adams and Stashak's Lameness in Horses, 7th Edition

Lameness of the Proximal Limb 727

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1

2A

Figure 5.128. A caudal to cranial radiographic image of a
proximal tibial subchondral cystic lesion with concurrent signs of
osteoarthritis within the MFT joint.

typically show an irregularity on the condylar surface
and thickening of the articular cartilage (Figure 5.129).
2B Because most cases of SCL are examined arthroscopi-
cally for treatment, the author does not routinely per-
form ultrasound of these cases unless there is concern
about the integrity of the medial meniscus. However, if
surgery is not an option at the owner’s request, then
ultrasound examination is recommended to obtain fur-
ther information about the integrity of the surrounding
articular cartilage and to later guide cyst injection. The
femoral condyle becomes quite superficial beneath the
skin when the limb is flexed, and the smooth, anechoic
nature of the articular cartilage on the curved condyle
can be easily appreciated superficial to the hyperechoic
3 subchondral bone (Figure 5.129B). In cases of SCL, a
defect is appreciated in the subchondral bone, the depths
of which sometimes cannot be appreciated. See
27
Chapter 3 for further details on the use of ultrasonogra-
phy to evaluate the MFT joint.

Treatment
Conservative therapy can be used in horses younger
than 1 year old in which lameness may or may not be
present. These horses may be treated with intra‐articular
medication if lameness is present. Corticosteroids in
4
particular may have an effect on the cystic lining to pre-
vent cyst enlargement, when physically injected into the
Figure 5.127. Grades of subchondral cystic lesions (SCLs). cyst lining. Whether intra‐articular administration of
Source: Reprinted with permission from Wallis et al. .
60
corticosteroids would have the same affect is unknown.
Young horses with SCLs should be confined to a small