Post-mortem ultrasonographic and computed tomographic features of the anatomical variations and acquired pathological bony changes of the lumbosacroiliac region in a mixed population of horses.
Authors: Scilimati Nicola, Beccati Francesca, Pepe Marco, Angeli Giovanni, Dall'Aglio Cecilia, Di Meo Antonio
Journal: Equine veterinary journal
Summary
# Editorial Summary Transrectal ultrasonography remains the gold standard for visualising the ventral lumbosacroiliac region in live horses, yet it frequently fails to establish a definitive diagnosis of back pain. In this post-mortem cadaver study, Scilimati and colleagues examined 42 lumbosacroiliac specimens using both ultrasonography and computed tomography to characterise the anatomical variations and acquired pathological bony changes (APBCs) present, investigating whether age, body mass, previous use and anatomical features correlate with disease severity. Lumbosacral spondylosis emerged as the most common finding (57%), alongside L5–L6 disc protrusions (36%) and abnormal disc echogenicity on ultrasound (71% at the lumbosacral level); notably, L5–L6 disc size abnormalities correlated significantly with promontorium location, lumbosacral disc morphology and L6 spinous process orientation. Age demonstrated a clear association with the severity of degenerative changes across the sacroiliac joints, intertransverse articulations and articular processes, whilst specific anatomical variations (such as L6 spinous process orientation and extremitas caudalis irregularity) were linked to both imaging findings and disc pathology. These findings underscore the substantial anatomical heterogeneity of the equine lumbosacroiliac region and suggest that apparently incidental imaging findings—which may be normal variants in some horses—warrant careful interpretation when correlating ultrasonographic or CT findings with clinical signs of back dysfunction.
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Practical Takeaways
- •High prevalence of lumbosacroiliac anatomical variations and acquired pathological changes in cadaver specimens suggests transrectal ultrasonography findings must be interpreted carefully in live horses with back pain, as variants may be incidental
- •Age-related increases in sacroiliac and lumbosacral spondylosis severity indicate older horses warrant closer monitoring of back function and may benefit from adapted work management
- •The correlation between specific anatomical variations (disc morphology, promontorium location, spinous process orientation) and pathological changes suggests these anatomical factors may predispose horses to certain degenerative patterns and could inform preventive management strategies
Key Findings
- •Type 2 lumbosacral disc morphology was most prevalent (21/42 specimens), with disc protrusions found in 15/42 specimens
- •Lumbosacral spondylosis was detected in 24/42 specimens with significant age-related correlation in severity across multiple joint structures
- •Anatomical variations including promontorium localisation, L6 spinous process orientation, and disc size abnormalities correlated with specific pathological changes (Cramér's V coefficients 0.41-0.69)
- •Abnormal echogenicity of lumbosacral discs was found in 30/42 specimens and associated with L6 spinous process orientation and disc size variability