Incidence, location and classification of 371 third carpal bone fractures in 313 horses.

This research article conducts a retrospective study of horses with third carpal bone fractures admitted to The Ohio State University Veterinary Hospital from 1979 to 1987. It describes the incidence, location, and classification of these fractures, finding considerable variation in fracture types, the affected limb, and the breed of horse.

Data Collection and Analysis

• The study involved a detailed review of medical records and radiographs of all horses with a third carpal bone fracture that were treated at The Ohio State University Veterinary Hospital between 1979 and 1987.
• This data collection methodology allowed the researchers to gather a significant sample of 371 fractures in 313 horses for close examination and classification.

Key Findings

• In the study, 57% of the affected horses were Standardbreds, 41% were Thoroughbreds, and only 1.6% were Quarterhorses. All the horse breeds studied were young racehorses, with an average age of 3.1 years.
• The research found that the third carpal fractures occurred more frequently in the right limb (60%) than in the left limb (40%). This disparity was even greater among Thoroughbreds specifically, with 67.5% of fractures occurring on the right and 27.1% on the left.
• The fractures were classified into eight types based on their size and anatomical location within the third carpal bone. These ranged from incomplete fractures of the radial facet to large frontal plane slab fractures involving both the radial and intermediate facets.
• The incidence of each fracture type was significantly different between Standardbreds and Thoroughbreds. Types 1 and 2 fractures were more common in Standardbreds, while Types 5 and 6 fractures were more frequently found in Thoroughbreds.

Implications and Suggestions

• The researchers posited that the observed differences between the two main horse breeds are likely related to the different gaits at which they race.
• The classification proposed in the study aims to more accurately describe the extent of injury and variations in fractures than the traditional division into chips or slabs.
• The researchers emphasized the importance of a high-quality skyline projection in correctly identifying these fractures, with over 10% of the fractures in the study detected solely on this view.