Caudal lumbar vertebral fractures in California Quarter Horse and Thoroughbred racehorses. (9th October 2014)

• Record Type: Journal Article
• Authors: Collar, E. M.; Zavodovskaya, R.; Spriet, M.; Hitchens, P. L.; Wisner, T.; Uzal, F. A.; Stover, S. M.
• Is Part Of: Equine veterinary journal. Volume 47:Number 5(2015:Sep.)
• Page Start: 573
• Page End: 579
• Publication Date: 2014-10-09
• Subjects: Horses -- Diseases -- Periodicals; 636.108905
• DOI: 10.1111/evj.12334
• Languages: English
• ISSNs: 0425-1644

Abstract

<abstract abstract-type="main"> <title>Summary</title> <sec id="evj12334-sec-0001" sec-type="section"> <title>Reasons for performing study</title> <p>To gain insight into the pathophysiology of equine lumbar vertebral fractures in racehorses.</p> </sec> <sec id="evj12334-sec-0002" sec-type="section"> <title>Objectives</title> <p>To characterise equine lumbar vertebral fractures in California racehorses.</p> </sec> <sec id="evj12334-sec-0003" sec-type="section"> <title>Study design</title> <p>Retrospective case series and prospective case–control study.</p> </sec> <sec id="evj12334-sec-0004" sec-type="section"> <title>Methods</title> <p>Racehorse <italic>post mortem</italic> reports and jockey injury reports were retrospectively reviewed. Vertebral specimens from 6 racehorses affected with lumbar vertebral fractures and 4 control racehorses subjected to euthanasia for nonspinal fracture were assessed using visual, radiographic, computed tomography and histological examinations.</p> </sec> <sec id="evj12334-sec-0005" sec-type="section"> <title>Results</title> <p>Lumbar vertebral fractures occurred in 38 Quarter Horse and 29 Thoroughbred racehorses over a 22 year period, primarily involving the 5th and/or 6th lumbar vertebrae (L5–L6; 87% of Quarter Horses and 48% of Thoroughbreds). Lumbar vertebral fractures were the third most common musculoskeletal cause of death in Quarter Horses and frequently involved a jockey injury. Lumbar vertebral specimens contained anatomical variations in the number of vertebrae, dorsal spinous processes and intertransverse articulations. Lumbar vertebral fractures examined in 6 racehorse specimens (5 Quarter Horses and one Thoroughbred) coursed obliquely in a cranioventral to caudodorsal direction across the adjacent L5–L6 vertebral endplates and intervertebral disc, although one case involved only one endplate. All cases had evidence of abnormalities on the ventral aspect of the vertebral bodies consistent with pre‐existing, maladaptive pathology.</p> </sec> <sec id="evj12334-sec-0006" sec-type="section"> <title>Conclusions</title> <p>Lumbar vertebral fractures occur in racehorses with pre‐existing pathology at the L5–L6 vertebral junction that is likely predisposes horses to catastrophic fracture. Knowledge of these findings should encourage assessment of the lumbar vertebrae, therefore increasing detection of mild vertebral injuries and preventing catastrophic racehorse and associated jockey injuries.</p> </sec> </abstract>