Relationship between spinal biomechanics and pathological changes in the equine thoracolumbar spine.
Authors: Townsend, Leach, Doige, Kirkaldy-Willis
Journal: Equine veterinary journal
Summary
# Editorial Summary: Spinal biomechanics and pathological changes in the equine thoracolumbar spine Understanding how movement patterns drive degenerative change in the horse's spine has significant implications for prevention and management of performance-related injury, yet the relationship between normal spinal mechanics and pathology remains incompletely characterised. Townsend and colleagues examined 23 functionally sound horses to map the distribution of degenerative lesions across the thoracolumbar spine and correlate their location with regional biomechanical demands. Ventrolateral osteophytes developed in 36% of specimens, predominantly between T10–T17 with the largest lesions at T11–T13—precisely where lateral bending and axial rotation are greatest—whilst dorsal spinous process impingement affected 86% of spines, clustering between T13–T18 but independent of local mobility patterns. Disc degeneration was identified in three of four sagittally sectioned specimens, localising to the first thoracic and lumbosacral joints where increased dorsoventral motion and disc thickness create mechanical stress. For practitioners, these findings suggest that lesion distribution reflects biomechanical load rather than simple wear, with particular vulnerability at transitional zones and high-mobility regions; this understanding may guide targeted assessment protocols and inform decisions about workload management in horses showing early signs of thoracolumbar dysfunction.
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Practical Takeaways
- •Expect to find osteophytes and kissing spine lesions in the mid-thoracic region of functionally normal horses; their presence alone may not indicate clinical significance
- •The thoracolumbar spine's biomechanics—particularly lateral bending and rotation in mid-thoracic vertebrae—directly predispose certain regions to degenerative changes; tailor exercise and training accordingly
- •Understanding biomechanical hotspots helps predict fracture risk and plan prevention strategies, particularly for high-impact or high-rotation activities
Key Findings
- •Ventrolateral osteophytes occurred in 36% of spines, predominantly between T10-T17 with largest lesions at T11-T13 where lateral bending and axial rotation are greatest
- •Dorsal spinous process impingement detected in 86% of spines, most common between T13-T18, without clear relationship to regional spinal mobility
- •Intervertebral disc degeneration observed in 75% of sectioned specimens, localized to first thoracic and lumbosacral discs with increased dorsoventral mobility and disc thickness