Some geometric properties of the third metacarpal bone: a comparison between the thoroughbred and standardbred racehorse.

The research study compares the geometric properties of the third metacarpal bone in young and adult Standardbred and Thoroughbred racehorses. Differences noticed in these properties are associated with the occurrence of fatigue fractures commonly seen in Thoroughbred but not in Standardbred racehorses.

Research Overview

• This study involves an examination of the geometric properties of the third metacarpal bone in racehorses, specifically comparing between the breeds: Standardbred and Thoroughbred, across different growth stages from young to adult.
• The aim of the comparison is to understand changes in the shape of the bone during the horse’s growth and the effect of consistent training on the same.

Main Findings

• The research discovers significant changes in the shape of the third metacarpal bone throughout the growth period, drastically observable in both breeds. However, these changes are tremendously accentuated in Thoroughbred horses compared to Standardbred horses as the horses mature.
• The study also notices a difference in the minimum moment of inertia between male and female horses, with males having larger moments of inertia throughout the diaphysis, the main or mid-section of a long bone.

Implications of the Study

• The key findings of the study reveal that the differences in the geometric properties of the third metacarpal bone between the two breeds are closely linked with the incidence of fatigue fractures.
• Such fractures are typically common in Thoroughbred racehorses, whereas they are uncommon in Standardbred racehorses.
• These insights suggest that the distinctive geometry of the third metacarpal bone might play a role in the development of fatigue fractures, which could provide an important understanding towards the designing of appropriate training and care regiments for different breeds of racehorses.