Ultrasonographic examination of the equine sacroiliac region.
Authors: Kersten A A M, Edinger J
Journal: Equine veterinary journal
Summary
# Ultrasonographic examination of the equine sacroiliac region Understanding normal sacroiliac ultrasound anatomy is essential for identifying pathology in this clinically significant region, yet detailed reference parameters have been lacking in equine practice. Kersten and Edinger established standardised imaging protocols by scanning 13 cadaver specimens and 13 sound horses using both transcutaneous (dorsal approach above the tubera sacrale) and transrectal techniques, enabling clear differentiation of key structures including the dorsal sacroiliac ligament, longissimus dorsi tendon, and the sacroiliac joint surfaces. Longitudinal ultrasound images proved particularly effective at distinguishing the longissimus dorsi tendon from the dorsal sacroiliac ligament, whilst transrectal examination successfully visualised the bony architecture of the sacroiliac joint and surrounding soft tissues. These findings are clinically valuable because ultrasound is widely accessible to equine practitioners, and having reliable normal reference parameters allows practitioners to confidently identify abnormalities associated with sacroiliac disease. The protocols described provide a practical framework for systematically examining this region in lame or back-painful horses, potentially improving diagnostic accuracy in cases where sacroiliac pathology is suspected.
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Practical Takeaways
- •Ultrasound examination of the sacroiliac region is readily accessible to most equine practitioners and can improve diagnosis of sacroiliac pathology using standardized reference parameters.
- •Both transcutaneous (above tubera sacrale) and transrectal approaches provide complementary information for complete sacroiliac assessment.
- •Knowing normal ultrasonographic anatomy of the region—particularly distinguishing the longissimus dorsi tendon from dorsal sacroiliac ligament—is essential for identifying pathological changes in horses presenting with back pain.
Key Findings
- •Ultrasonographic examination using transcutaneous and transrectal approaches provides clear images of sacroiliac joint structures and adjacent tissues in normal horses.
- •Longissimus dorsi tendon can be clearly distinguished from dorsal sacroiliac ligament on longitudinal ultrasound images at the level of tubera sacrale.
- •Transrectal ultrasonography allows evaluation of sacroiliac joint bony surfaces and comparison with contralateral side.
- •Ultrasonography is a useful diagnostic aid for sacroiliac joint diseases and adjacent lesions in horses.