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Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc2025; 10406387251336267; doi: 10.1177/10406387251336267

A retrospective study of radial fractures in racehorses in California, 2006-2022.

Abstract: Radial fractures are relatively uncommon (0-1%) injuries in postmortem studies of racehorses, and few cases have been published. We describe here a series of 42 cases of radial fractures observed in California racehorses. Autopsy findings from all racehorses submitted for postmortem examination between 2006 July 1 and 2022 June 30 that had a recorded radial fracture were evaluated. We included 42 horses (30 Thoroughbreds, 12 Quarter Horses), most of which were 3-5-y-old. Catastrophic radial fracture was observed in 30 (71%) horses; in the remaining 12 (29%) horses, the fracture of the radius was considered an incidental finding. All of the catastrophic radial fractures were complete, displaced, and comminuted; 70% were articular and 30% were non-articular; 61% were open and 39% were closed; 83% were diaphyseal to distal epiphyseal and 17% were proximal epiphyseal. Nine of the 30 horses with catastrophic fracture had a preexisting periosteal callus associated with the main line of fracture. Among Quarter Horse racehorses, the frequency of callus in radial fractures tended to be higher ( = 0.083) in 3-y-olds compared with other ages. In 6 of these 9 cases, the callus was located along the cranial aspect of the distal third of the diaphysis. All incidental cases consisted of osteochondral fragmentations, which occurred most frequently on the cranial border of the intermediate facet of the distal articular surface of the radius. Knowledge of the common sites of stress fractures or osteochondral stress remodeling in the radius can help to focus autopsies and to improve the characterization and interpretation of those lesions.
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Publication Date: 2025-07-23 PubMed ID: 40702641PubMed Central: PMC12289619DOI: 10.1177/10406387251336267Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research paper provides a detailed analysis of radial fractures in racehorses in California, covering a period from 2006 to 2022. The study found that such fractures are relatively rare but can be quite severe when they do occur, particularly in younger horses.

Objective of the Study

  • This research was initiated to investigate radial fractures in racehorses, injuries that had previously been observed to have a 0-1% occurrence in postmortem studies.
  • The aim was to get a better understanding of how frequently these fractures occur, their characteristics, and any commonalities that might exist between the cases. This would allow for better characterization, interpretation, and treatment of these lesions.

Methodology

  • The study was based on autopsy reports of racehorses from California examined between July 1, 2006, and June 30, 2022.
  • All the subjects had a recorded radial fracture. The study included a total of 42 horses, of which 30 were Thoroughbreds and 12 Quarter Horses. Most of these horses were aged between 3 to 5 years.

Findings of the Study

  • The research found that catastrophic radial fractures were evident in 71% of the horses. In these cases, the fractures were complete, displaced, and comminuted. Among them, 70% were articular, and 30% were non-articular; 61% were open, and 39% were closed. Also, 83% of these fractures were diaphyseal to distal epiphyseal, and 17% were proximal epiphyseal.
  • In the remaining 29% of the horses, the fracture was considered an incidental finding.
  • Nine of the thirty horses with catastrophic fractures had a pre-existing periosteal callus associated with the main line of fracture. This occurrence was more frequent in 3-year-old Quarter Horses.
  • All incidental cases were characterized by osteochondral fragmentations, most commonly on the cranial border of the intermediate facet of the distal articular surface of the radius.

Implication of the Study

  • The research concludes with the assertion that understanding the common sites of stress fractures or osteochondral stress remodeling in the radius will help focus autopsy efforts and improve the characterization and interpretation of such lesions.
  • Such an understanding can guide further research, shape diagnostic procedures, influence treatment strategies and overall improve the health and performance of racehorses.

Cite This Article

APA
Schild CO, Nyaoke A, Asin J, Henderson EE, Blea JA, Stover SM, Uzal FA. (2025). A retrospective study of radial fractures in racehorses in California, 2006-2022. J Vet Diagn Invest, 10406387251336267. https://doi.org/10.1177/10406387251336267

Publication

Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc
ISSN: 1943-4936
NlmUniqueID: 9011490
Country: United States
Language: English
Pages: 10406387251336267
PII: 10406387251336267

Researcher Affiliations

Schild, Carlos O
  • California Animal Health and Food Safety Laboratory System, San Bernardino branch, University of California-Davis, Davis, CA, USA.
Nyaoke, Akinyi
  • California Animal Health and Food Safety Laboratory System, San Bernardino branch, University of California-Davis, Davis, CA, USA.
Asin, Javier
  • California Animal Health and Food Safety Laboratory System, San Bernardino branch, University of California-Davis, Davis, CA, USA.
Henderson, Eileen E
  • California Animal Health and Food Safety Laboratory System, San Bernardino branch, University of California-Davis, Davis, CA, USA.
Blea, Jeff A
  • California Horse Racing Board, Arcadia, CA, USA.
Stover, Susan M
  • JD Wheat Veterinary Orthopedic Research Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
Uzal, Francisco A
  • California Animal Health and Food Safety Laboratory System, San Bernardino branch, University of California-Davis, Davis, CA, USA.

Conflict of Interest Statement

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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