Fractures–a preventable hazard of racing thoroughbreds.

This research article investigates the occurrence and causes of fractures in Thoroughbred racehorses, particularly those linked to stress fractures. The study further explores factors such as microdamage, remodelling and training schedules in preventing these injuries, emphasizing on the need for effective bone repair before the horse is subjected to intensive training.

Understanding Fractures in Thoroughbred Racehorses

In Thoroughbred racehorses, fractures, particularly stress fractures, are a common cause of loss. The research reveals that:

• A distinct segment of these injuries take place absent a certain traumatic event.
• These fractures often have characteristic features of stress fractures, seeming consistent in their morphology.
• Commonly, these fractures share locations with incomplete cracks and are frequently linked to pre-existing pathology such as periosteal and endosteal new bone formation, including intracortical remodelling.

Bone Adaptation to its Mechanical Environment

An essential part of this research focuses on the ability of bone to adapt to mechanical environment alterations. This is evidenced in Thoroughbred racehorses as follows:

• The geometric properties of the third metacarpal bone exhibit changes in response to training.
• The above modifications are linked to lower bone strains.

Impact of Training Before Adaptive Response is Completed

The research exposes the risks that vigorous training before full completion of the adaptive response can bring about.

• Early intense training before bone strain is reduced escalates the risk of fatigue damage.
• Bone fatigue is linked to progressive microdamage, contributing significantly to the development of stress fractures.

The Role of Bone Remodelling

The biological repair mechanism of bone, referred to as remodelling, plays a substantial role in both the development and prevention of stress fractures.

• While remodelling can lead to stress fractures, it is also instrumental in their prevention.
• Horses subjected to exercise before full bone repair pose a significantly higher risk of experiencing a catastrophic stress fracture.

Key Questions Addressed in the Study

The paper also addresses critical questions concerning the impact of microdamage, remodelling, and training schedules in preventing stress fractures.