Proximal sesamoid and condylar fractures risk assessed by inertial sensors

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The majority of proximal sesamoid and condylar fractures occurred in horses identified as high risk by inertial measurement unit sensors

J Am Vet Med Assoc. 2026 Feb 13:1-10. doi: 10.2460/javma.25.08.0556. Online ahead of print.
Authors
Nicholas P Hall 1 , Denise Mc Sweeney 1 , Mikael Holmströem 2 , Wooyoung Kim 3 , Yuan Wang 3 , Kevin D Donahue 2 , Scott E Palmer 4 5 , David H Lambert 2 , Warwick M Bayly 1
Affiliations

1 1Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA.
2 2StrideSAFE USA, Midway, KY.
3 3Department of Mathematics and Statistics, College of Arts and Sciences, Washington State University, Pullman, WA.
4 4Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY.
5 5New York State Gaming Commission, Schenectady, NY.

PMID: 41689963
DOI: 10.2460/javma.25.08.0556

Abstract

Objective: To determine whether targeted lesion-specific algorithms developed from data collected with accelerometer-based inertial measurement units worn by racing Thoroughbreds could retrospectively identify horses at high risk of incurring forelimb condylar or proximal sesamoid fractures.

Methods: Fracture-specific algorithms were generated from July 2021 to December 2024 with accelerometer data from 42,623 races by 15,755 horses, including 54 races by 23 horses that subsequently suffered condylar fractures and 90 races by 31 horses that later sustained proximal sesamoid fractures. Fracture-specific algorithms placed horses into relative risk groups: green (low risk; score = 1), amber (asymmetry while racing; score = 2), and red (high risk; scores of 3 to 5 [5 = most at risk]) based on inertial measurement unit data that were compatible with the subsequent occurrence of either fracture.

Results: The positive predictive values were 0.09 for condylar and 0.08 for sesamoid fractures, respectively, in the most-at-risk horses. For horses with ≥ 3 starts and mean risk scores > 3.0 over 3 consecutive starts, positive predictive value was 0.74 and OR was 133 (95% CI, 23.5 to 753) compared to horses with mean scores < 3.0. Eighty-nine percent of all 53 fractures occurred in the red-risk group. Greater than 98.8% of horses with a risk score < 5 did not suffer either fracture, while ≤ 1.2% of the nonfracture cases received a risk score of 5.Conclusions: Most forelimb condylar and proximal sesamoid fractures were incurred by horses retrospectively identified as being at high risk by these fracture-specific algorithms. Having ≥ 3 risk scores/horse greatly increased the algorithms' precision.Clinical relevance: Fracture-specific algorithms can identify horses at high risk of future condylar or proximal sesamoid bone fractures, thereby assisting veterinarians tasked with identifying and clinically evaluating them.Keywords: catastrophic injury; condylar fractures; injury risk; sensors; sesamoids.