A study on the pathogenesis of equine sesamoiditis: the effects of experimental occlusion of the sesamoidean artery.
Authors: Cornelissen, Rijkenhuizen, Buma, Barneveld
Journal: Journal of veterinary medicine. A, Physiology, pathology, clinical medicine
Summary
# Editorial Summary: Sesamoiditis and Vascular Occlusion Cornelissen and colleagues investigated whether compromised blood supply to the proximal sesamoid bones (PSBs) might initiate sesamoiditis by experimentally blocking the sesamoidean artery—the primary nutrient vessel to these bones—in five adult Dutch Warmblood horses using polyvinyl alcohol foam particles. Over 35 days, they monitored clinical signs, radiographic changes, and histological findings (including examination of neuropeptides substance P and CGRP), with bone perfusion tracked using fluorescent markers. Whilst all horses developed mild transient lameness, histological analysis revealed that an average of 60% of PSB tissue became avascularised (range 37–89%), yet only the horse with the most extensive occlusion showed bone necrosis; radiographic changes were minimal, and soft tissue neuropeptide distribution remained unaffected. These findings suggest that vascular disruption alone is insufficient to produce the pathological hallmarks of clinical sesamoiditis, challenging the notion that circulatory disturbance is the primary driver of the condition. For practitioners, this implies that whilst ischaemia may contribute to sesamoiditis in susceptible horses, other factors—mechanical loading patterns, inflammatory cascades, or biomechanical stress—likely play equally or more significant aetiological roles and warrant investigation as potential intervention points.
Read the full abstract on PubMed
Practical Takeaways
- •Reduced blood supply to the proximal sesamoid bones is not sufficient to explain sesamoiditis pathogenesis; other factors (biomechanical, inflammatory, or traumatic) are likely more important in disease development
- •Clinical lameness and bone changes associated with sesamoiditis cannot be attributed to simple vascular insufficiency, suggesting veterinary investigation should focus on other potential causes
- •These findings challenge the traditional vascular ischaemia theory and may shift diagnostic and therapeutic approaches away from solely vascular-focused interventions
Key Findings
- •Experimental occlusion of the sesamoidean artery caused only mild transient lameness in all five horses, which gradually diminished over the 35-day study period
- •60% of proximal sesamoid bone vascularization was lost on average (range 37–89%) without producing radiographic or histological changes consistent with clinical sesamoiditis
- •Only the horse with the greatest extent of arterial occlusion (>89%) developed bone necrosis and reactive fluorochrome uptake
- •Circulatory disturbances alone are unlikely to be a primary aetiological factor in the development of sesamoiditis