Postinjury performance for differing humeral stress fracture locations in the racing thoroughbred.
Abstract: To assess the influence of humeral stress fracture location on the time to return to racing and postinjury performance of thoroughbred racehorses. Methods: Retrospective study (1992-2015). Methods: Thoroughbred racehorses (n = 131) that presented for lameness with the sole diagnosis of humeral stress fractures in the lame limb, as determined by scintigraphy or radiology. Methods: Sex, fracture site, age, starts, earnings, and average earnings per race were examined for differences in pre-stress and post-stress fracture diagnosis for the entire population as well as individual stress fracture locations (general linear model, χ tests). Pre-stress and post-stress fracture performance for the three stress fracture locations were assessed: (1) earnings pre-stress and post-stress fracture (Kruskal-Wallis one-way analysis of variance), (2) average earnings per start prefracture, and (3) average earnings per start postfracture (Wilcoxon signed-rank tests). Results: Stress fracture locations were caudodistal (n = 36), craniodistal (n = 43), and caudoproximal (n = 52). One hundred ten of 131 horses raced postfracture, and 54 of 131 horses raced prefracture. Age at injury was 43.61 months caudodistal, 33.48 months caudoproximal, and 36.65 months craniodistal. Horses returned to race at a median of 244 days (range, 218-272). Postfracture earnings per start were greater for caudodistal vs caudoproximal (P = .04). Conclusions: There were no differences in prefracture earnings or fracture site and sex or limb affected. Return-to-race time varied by location but not significantly. Differences in earnings preinjury and postinjury were not significant. Horses with a stress fracture at the caudodistal location earned significantly more compared with horses with a stress fracture at the caudoproximal location after they returned to race. Conclusions: Thoroughbred racehorses have a good prognosis for return to racing regardless of fracture location.
© 2020 The American College of Veterinary Surgeons.
Publication Date: 2020-07-17 PubMed ID: 32678472DOI: 10.1111/vsu.13447Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- 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 aims to examine the impact of stress fracture location in the humerus on the time taken for thoroughbred racehorses to return to racing and their performance post-injury. Findings suggest that income earned per race post-injury significantly increased for horses with stress fractures at the caudodistal location compared to caudoproximal location. Generally, thoroughbred racehorses demonstrated a good probability of returning to races, regardless of the location of the fracture.
Research Methodology
- Conducted a retrospective study over the period 1992-2015, studying 131 thoroughbred racehorses that showed lameness resulting from humeral stress fractures as determined via scintigraphy or radiology.
- A range of variables including sex, fracture site, age, number of races, earnings, and average earnings per race were reviewed for fluctuations pre-stress and post-stress fracture diagnosis for all horses and for individual stress fracture locations.
- The study used the general linear model and χ tests to examine pre-stress and post-stress fracture performance at the three detected stress fracture locations. It applied the Kruskal-Wallis one-way analysis of variance to calculate earnings pre-stress and post-stress fracture. Additionally, the Wilcoxon signed-rank tests helped to ascertain the average earnings per race pre and post-injury.
Research Outcomes
- Identified stress fractures located at caudodistal (n = 36), craniodistal (n = 43), and caudoproximal (n = 52) parts of the humerus.
- Most horses were able to participate in races post-injury – 110 out of 131. Meanwhile, only 54 out of 131 horses were able to compete in races before the fracture.
- The age of these horses at the time of injury averaged 43.61 months for caudodistal, 33.48 months for caudoproximal, and 36.65 months for craniodistal fractures.
- Horses could return to races approximately 244 days post-fracture, with the exact return time ranging between 218 and 272 days.
- Interestingly, horses with fractures at the caudodistal position were able to earn significantly more per race compared to those with stress fractures at the caudoproximal location post-fracture (P = .04).
Conclusions
- No significant difference was found in earnings before the fractures or between fracture sites and sex or affected limb.
- The return-to-race period varied according to the fracture location, however, the variation was not significant.
- There was no significant difference in earnings before and after the injury.
- Thoroughbred racehorses generally have a good prognosis for returning to racing, regardless of the fracture location.
Cite This Article
APA
Henderson B, Bramlage LR, Koenig J, Monteith G.
(2020).
Postinjury performance for differing humeral stress fracture locations in the racing thoroughbred.
Vet Surg, 49(7), 1412-1417.
https://doi.org/10.1111/vsu.13447 Publication
Researcher Affiliations
- Rood and Riddle Equine Hospital, Lexington, Kentucky.
- Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
- Department of Population Medicine, University of Guelph, Guelph, Canada.
MeSH Terms
- Animals
- Female
- Fractures, Stress / veterinary
- Horses / injuries
- Horses / physiology
- Humeral Fractures / veterinary
- Humerus / injuries
- Male
- Physical Conditioning, Animal
- Radiography / veterinary
- Radionuclide Imaging / veterinary
- Retrospective Studies
- Sports
References
This article includes 15 references
- Dimock AN, Hoffman KD, Puchalski SM, Stover SM. Humeral stress remodelling locations differ in Thoroughbred racehorses training and racing on dirt compared to synthetic racetrack surfaces.. Equine Vet J 2013;45:176-181.
- Stover SM, Johnson BJ, Daft BM. An association between complete and incomplete stress fractures of the humerus in racehorses.. Equine Vet J 1992;24:260-263.
- Sammons SC, Stover SM. Review of patterns of humeral fracture in thoroughbred racehorses.. In: Proceedings from the 55th Annual Convention of the American Association of Equine Practitioners; December 5-9, 2009; Las Vegas, NV; 55:192-196.
- Riggs CM. Review: fractures-a preventable hazard of racing thoroughbreds?. Vet J 2002;163:19-29.
- Carrier TK, Estberg L, Stover SM. Association between long periods without highspeed workouts and risk of complete humeral or pelvic fracture in Thoroughbred racehorses: 54 cases (1991-1994).. J Am Vet Med Assoc 1998;212(10):1582-1587.
- Entwistle RC, Sammons SC, Bigley RF. Material properties are related to stress fracture callus and porosity of cortical bone tissue at affected and unaffected sites.. J Orthop Res 2009;27(12):1272-1279.
- Stover SM, Murray A. The California Postmortem Program: leading the way.. Vet Clin North Am Equine Pract 2008;24:21-36.
- O'Sullivan CB, Lumsden JM. Stress fractures of the tibia and humerus in Thoroughbred racehorses: 99 cases (1992-1993).. J Am Vet Med Assoc 2003;222:491-498.
- Mackey VS, Trout DR, Meagher DM, Hornof WJ. Stress fractures of the humerus, radius and tibia in horses: clinical features and radiographic and/or scintigraphy appearance.. Vet Radiol 1987;28:26-31.
- Kraus BM, Ross MW, Boswell RP. Stress remodelling and stress fracture in the humerus in four standard racehorses.. Vet Radiol Ultrasound 2005;46:524-528.
- Johnson BJ, Stover SM, Daft BM. Causes of death in racehorses over a 2-year period.. Equine Vet J 1994;26:327-330.
- Stover SM. Diagnostic workup of upper-limb stress fractures and proximal sesamoid bone stress remodelling.. In: Proceedings from the 59th Annual Convention of the American Association of Equine Practitioners; December 7-11, 2013; Nashville, TN; 59:427-435.
- Pollock S, Hull ML, Stover SM, Galuppo LD. A musculoskeletal model of the equine forelimb for determining surface stresses and strains in the humerus-part 1. Mathematical modeling.. J Biomed Eng 2008;130:041006.
- Pollock S, Stover SM, Hull ML, Galuppo LD. A musculoskeletal model of the equine forelimb for determining surface stresses and strains in the humerus-part II. Experimental testing and model validation.. J Biomed Eng 2008;130:041007.
- Cheetham J, Riordan AS, Mohammed HO, McIlwraith CW, Fortier LA. Relationships between race earnings and horse age, sex, gait, track surface and number of starts for Thoroughbred and Standardbred racehorses in North America.. Equine Vet J 2010;42(4):346-350.
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists