Ischaemic necrosis of the navicular bone and its treatment.
Authors: Colles
Journal: The Veterinary record
Summary
# Editorial Summary: Ischaemic necrosis of the navicular bone and its treatment Colles' 1979 investigation examined post-mortem tissue from 95 control horses alongside 16 cases clinically diagnosed with navicular disease, seeking to clarify the pathological mechanisms underlying this chronic condition. Contrary to prevailing assumptions, erosions and discoloration of the flexor cartilage proved equally present in both groups, suggesting these changes were incidental rather than aetiologically significant. The pivotal finding was universal thrombosis of the distal navicular nutrient arteries in affected horses, correlated with anatomical alterations to the distal nutrient foramen—specifically a transition from normal morphology to rounded or flask-shaped configurations that compromised vascular patency. This vascular obstruction model fundamentally reframes navicular disease as an ischaemic condition rather than a primary degenerative one, rendering many then-current therapeutic approaches ineffective. Preliminary results with anticoagulant therapy warranted further investigation, though long-term efficacy remained unestablished—directing the profession toward vascular interventions rather than mechanical or cartilage-focused treatments in future management strategies.
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Practical Takeaways
- •Cartilage erosions and discoloration on the navicular bone alone are not reliable indicators of navicular disease and should not guide diagnosis or treatment decisions
- •Vascular insufficiency (thrombosis of nutrient arteries) appears to be the primary pathological mechanism in navicular disease, suggesting anticoagulant or vascular-targeted therapies warrant investigation
- •Existing standard treatments for navicular disease are largely ineffective; practitioners should consider novel approaches while longer-term studies on anticoagulation are completed
Key Findings
- •Erosions and discoloration of flexor cartilage on the navicular bone occurred equally in control horses (95) and diseased horses (16), indicating these are not diagnostic features of navicular disease
- •All 16 cases of navicular disease showed thrombosis of distal navicular nutrient arteries
- •Thrombosis of nutrient arteries correlated with morphological change of the distal nutrient foramen from normal to rounded or flask shape
- •Conventional treatments for navicular disease were of limited value; preliminary anticoagulant therapy showed promise but long-term efficacy remained unproven