Distal splint bone fractures in the horse: an experimental and clinical study.

This research aims to understand what causes distal splint bone fractures in horses. Through experiments and clinical studies, it was found that certain movements and conditions can predispose horses to these fractures; moreover, the majority of these fractures heal spontaneously and don’t cause pain or lameness.

Research Methodology

• The study examined both in vitro and in vivo circumstances to understand the aetiology of distal splint bone fractures. The research involved observing the changes in the position of the distal ends of splint bones and the tension in the interosseous tendons during the extension and flexion of the fetlock, the joint that connects the animal’s foot to its leg.

Findings – Experimental Study

• During in vitro examinations, the researchers found that extending the fetlock didn’t alter the position of the distal ends of the splint bones. However, they noted a surge in tension in the interosseous tendons.
• On flexing the fetlock, a slight outward displacement of the distal ends of the splint bones occurred.
• The researchers suggest that desmitis of the suspensory ligament accompanying such movements may cause the ends of the splint bones to move, predisposing them to fatigue fractures.

Findings – Clinical Study

• In the clinical examination of 87 horses, 114 splint bone fractures were identified.
• At least 70% of these horses exhibited suspensory desmitis, which is inflammation of a key ligament used in walking and running. This condition appears to be correlated with the fractures, supporting the experimental results.
• Follow-up information was available for 24 of the horses. More than 80% of their fractures healed spontaneously without medical intervention.
• The fractures that did not naturally heal – known as non-union fractures – neither caused pain nor lameness in the horses according to the observational data.

Implications of the Study

• This study provides insight into the cause of distal splint bone fractures, potentially enabling better preventive measures. It also offers reassurance that most fractures heal on their own and that even those that don’t typically aren’t painful or debilitating.