Each year at the British Equine Veterinary Association Congress (BEVA), the organization awards prizes to top student presentations in the clinical research portion of the program. The 2007 award winners’ talks were both rooted in orthopedics, and both received the award for their practical relevance to veterinarians.

Low-Field MRI and the Fetlock
Ceri Sherlock, BVetMed (Hon), MRCVS, a large animal resident in the University of Georgia Department of Large Animal Medicine, received an award for her presentation of a study that revealed the usefulness of low-field MRI for diagnosing cartilage injury of the fetlock that doesn’t show up on radiographs. This type of MRI is the lower-cost, portable version, so this study is applicable to the ambulatory practitioner that might be looking into adding this technology to his or her practice.

Sherlock worked with veterinarians at Bell Equine Veterinary Clinic in Mereworth, United Kingdom, and Diergeneeskundig Centrum Noord Nederland, in the Netherlands, to collect case information for the study. She and her colleagues performed MRI on 13 horses under standing sedation to investigate "lameness originating from the fetlock joint that was unexplained on standard radiography," according to her abstract. They conducted repeat examinations and completed telephone questionnaires with owners and referring veterinarians.

She reported that all 13 horses displayed a variety of signal changes that signified subchondral (cartilage in the bone end) bone damage. Seven of the horses were available for follow-up; four of those horses were sound and three were lame. Sherlock and her co-authors concluded, "Lameness originating from the fetlock joint may be associated with subchondral bone damage in horses of any signalment in the absence of radiographic changes. Low-field MR imaging can be a useful tool in the diagnosis of osteochondral injury."

Traumatic Overload Injuries
The other award went to Elizabeth Barr, BVMS, CertES(Orth), Dipl. ECVS, MRCVS, a PhD student in Veterinary Clinical Sciences at the University of Liverpool in the U.K., for her research involving post-mortem examinations of fetlock joints for palmar/plantar osteochondral disease (POD) in 64 Thoroughbreds. This condition is also called "traumatic osteochondrosis."

Barr and her colleagues at Liverpool and at The Hong Kong Jockey Club analyzed the findings of post-mortem examinations on forelimb and hind limb fetlock joints from racehorses that required euthanasia on humane grounds. PM findings were also correlated to some preliminary risk factors from the horses’ racing histories. They assigned scores for the POD, wear lines, cartilage loss, marginal remodeling, linear fissures (tiny cracks), and dorsal impact injuries on each joint. POD was found to be extremely common, affecting 67% (43/64) of the horses. There was a positive correlation between the POD and dorsal impact injuries, and other signs of fetlock joint disease.

The relationship between POD and linear fissures is more complex, but it appeared that a mild degree of linear fissure formation was protective against development of POD,  but this should be further analyzed with a larger group of animals, said the authors. Analysis of the horses’ racing histories indicated that horses with more race starts, that were older at retirement from racing, that had been in training for a greater number of seasons and that had greater total winnings were most at risk for development of POD. They noted that this data "supports the theory that POD is a manifestation of traumatic overload."

They concluded that POD appears to be extremely common in racing Thoroughbreds and that further research into the risk factors and biological mechanisms behind this condition are needed.

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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