Page 302 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.7c The axial skeleton – pelvis 277

VetBooks.ir pattern on ultrasound. Calcifications in the liga- to differentiate the tuber sacrale from the SI joint.
There is wide variation between reports of the asso-
ment may indicate a chronic injury. While ultraso-
nography is useful for diagnosis, findings should be
radiopharmaceutical uptake. One study found that
interpreted in combination with other diagnostic ciation between SI joint pathology and abnormal
modalities. 99% of horses with pain localised to the SI region
Scintigraphic images of the SI region can be had abnormalities of this region on nuclear scin-
obtained with the detector camera placed above the tigraphy. However, radiopharmaceutical uptake is
cranial pelvis. In this view, the joint is covered by also thought to be affected by a number of other
the wing of the ilium and lies approximately half- factors including the conformation of the sacrum,
way between the tuber sacrale and the tuber coxae. degree of gluteal muscling and pelvic orientation, as
Oblique views of the ilial wings are useful in order well as age-related changes and pathology. Indeed,
in a second study by the same group, only 43% of
1.523 horses that showed a positive response to infiltration
of local anaesthesia in the SI region had abnormal
radiopharmaceutical uptake on nuclear scintigraphy
(Fig. 1.524).
Infrared thermographic imaging has been used as
a screening tool for horses with lameness and back
pain; however, its use in SI disease is controversial
and has yet to be established.
Although direct intra-articular injection of the SI
joint is not possible in the living horse, techniques
for periarticular anaesthesia with a local anaes-
thetic agent to confirm a diagnosis of pain in this
region have been described. The medial approach is
Fig. 1.523 The ultrasound image on the left shows favoured by most clinicians and the same approach
an abnormal ventral sacroiliac joint with significant can be used to medicate this area with anti-inflam-
periarticular bone remodelling. The image on the matories. The technique involves appropriate
right is a normal joint. (Photos courtesy Diane Isbell) restraint and sedation of the horse to be injected,

1.524

Fig. 1.524 Nuclear
scintigraphy of a 10-year-old
Belgian Warmblood mare
with a 1-month history of
stiffness in the trot and
resistance to jumping. The
images show increased
radiopharmaceutical uptake
in the right sacroiliac region.