Mechanical and morphometric analysis of the third carpal bone of Thoroughbreds.

The research article studies the mechanical and morphometric properties of the third carpal bone (C3) in Thoroughbred horses of different training levels and age. The results confirm that trained horses show increased stiffness and area fraction in their C3 bone when compared to their untrained counterparts.

Research Method

• The researchers collected the third carpal bone (C3) from both forelimbs of 27 Thoroughbred horses.
• Based on age, training level, and past history, these bones were divided into five different categories which included yearlings, 2-3 year old horses that were untrained, trained 2-year old horses, trained 3-year old horses, and 3-year old, trained horses with carpal pathological features.
• The team then cut a transverse section measuring 5 mm thick from the subchondral bone, precisely 10 mm from the proximal articular surface of all the bone samples. They then performed a detailed radiography on the samples.
• Indentation tests were carried out on the proximal surface of the bone slices at 5 mm intervals.
• The stiffness of the underlying cancellous bone was assessed from the slope of the load against displacement graph.
• They compared topographic plots of stiffness measurements with radiographs of each sample.
• The values obtained were then averaged to derive measures for the radial and intermediate facets, and for regions at intervals of 5, 10, 15 and 20 mm from the dorsal margin of C3.
• They also measured the area fraction, determined as 1-p where p is porosity, of the radial and intermediate facets using an automated image analysis system.

Research Findings

• The researchers found that the third carpal bone (C3) of trained horses showed significant increases in stiffness and area fraction compared to the bones from untrained horses.
• The radial facet of the C3 bone in horses with pathological features showed significantly higher stiffness and area fraction than bones from all other groups.

Significance of the Study

• This research expands the understanding of the effects of training on the bone structure of Thoroughbred horses, specifically the third carpal bone (C3), which can be beneficial in improving training strategies and preventing injuries.
• The findings could also be used in clinical settings for the diagnosis and treatment of carpal pathologies in Thoroughbreds.