Wedge-shaped conformation of the dorsolateral aspect of the third tarsal bone in the Thoroughbred racehorse is associated with development of slab fractures in this site.

The research outlines that there is a particular abnormal bone shape in Thoroughbred racehorses, known as ‘wedge-shaped conformation’ in the third tarsal bone (T3), that seems to be associated with the increased occurrence of slab fractures. The study hopes that the results can aid in making informed decisions about the suitability of horses for racing in pre-purchase examinations.

Research Methodology

• In the quest to ascertain the anecdotal evidence that many cases of third tarsal bones (T3) fractures are associated with an abnormal bone shape, the researchers used radiographs from 20 horses. There were 10 normal horses and 10 horses with slab fractures of T3.
• The researchers took the radiographic measurements of the maximum and minimum width between the proximal and distal articular surfaces of the dorsolateral aspect of the horses’ tarsus in a standardized dorso-50 degrees medial-palmarolateral projection.
• To avoid any potential discrepancies that could result from image magnification, the team used ratios of these values in their comparisons among the horses.

Research Findings

• According to the research results, the wedge-shaped conformation of T3, where the bone’s articular surfaces converge and then diverge again at the dorsolateral aspect, was predominant in horses that experienced a T3 fracture compared to the control group.
• This finding implies that horses exhibiting wedge-shaped T3 appear to have an elevated risk for slab fractures. This abnormal bone shape may serve as a pre-existing radiological abnormality in cases of these fractures.

Implications of the Research

• This information provides valuable insights that can be used to determine the suitability of a horse for racing during prepurchase examinations.
• Horses with the identified abnormal bone shape may be considered high-risk for sustaining injuries, thereby affecting their performance and overall value in racing.
• Overall, this study emphasizes the need for careful definition and understanding of ‘normal’ skeletal anatomy in the selection and management of racing horses.