Hallmarq Veterinary Imaging Presents Dr Sue Dyson's Patient, A Showjumper Who Wanted to Stay on the Left Lead

Sue Dyson, FRCVS, is Senior Orthopaedic Clinician in the Centre for Equine Studies at the Animal Health Trust in Newmarket, England. The Animal Health Trust (AHT) operates a referral clinic for cases of lameness in sport horses, which is Dyson's specialty. AHT has advanced diagnostic imaging capabilities that are usually not available in equine veterinary hospitals.

Dr Sue Dyson of the Animal Health Trust is Newmarket, England performs systematic lameness exams on horses referred to the clinic for diagnosis or treatment. (Sue Dyson/Hoofcare Publishing image)

Imagine Sue Dyson examining Thomas, a five-year-old warmblood, who competes in low-level showjumping.

Thomas was referred to the Animal Health Trust because he was reluctant to land from a fence with the right forelimb leading. He had become awkward turning to the left and sometimes felt "pottery" (unlevel or unstable) in front. Thomas's vet had detected some swelling in the region of the left front foot's coffin joint, just above the coronary band. He was sound on a straight line but on a circle he showed left forelimb lameness on the left rein, which was worse on a firm surface that a soft one.

Nerve blocks were used to desensitize the back of the foot and this eliminated the left forelimb lameness. On a separate occasion, an injection of a local anesthetic into the coffin joint also made Thomas sound.

The impar ligament of the navicular bone is known as the Distal Sesamoidean Impar Ligament or DSIL. It anchors the navicular bone by connecting it to the coffin bone (P3). This ligament is very deep inside the foot and is not visible on a radiograph. (HC Biovision plastination image, uesd with permission)

X-rays of the foot were taken, but the vet saw no abnormalities. The vet explained that although primary injuries of the coffin joint can occur, a positive response to nerve-blocking did not rule out the possibility of injury to one of the other related structures.

A treatment plan devised by the horse's regular vet directed that Thomas’s coffin joint was treated with an injection of corticosteroids and hyaluronan, which made him sound within a few days and able to resume full work. He continued to progress well for about six weeks but clinical signs recurred. Never blocks were repeated and yielded similar results.

This MRI shows what a normal, undamaged DSIL looks like. It appears like a solid bank of white leading from the navicular bone to the inside of the coffin bone. The veterinarian interpreting the MRI would hope to see the DSIL looking the one in this image. (Hallmarq reference image)

The vet examined the collateral ligaments of the coffin joint, just above the coronary band, and could see no abnormalities. It was therefore suggested that an MRI scan should be carried out to try to establish a more definitive diagnosis. MRI often identifies injuries which are invisible when using other techniques such as x-rays or ultrasound, particularly when the problem is in the foot.

The MRI scan, performed at the Animal Health Trust, revealed that Thomas had sustained an avulsion fracture—an injury to the bone in a place where a tendon or ligament attaches to it—at one side of the attachment of the distal sesamoidean impar ligament to the pedal (coffin) bone. Clearly this was a problem that was going to require rest before Thomas would happily swap leads again.

Damaged DSIL: Deciding to look into the foot in search of a root cause of the lameness was delayed for months with this horse, while the vet treated what might be the horse's problem. This type of injury is relatively rare but can be diagnosed through advanced imaging. The MRI showed that the foot was damaged in the region of the distal sesamoidean impar ligament (DSIL) in the navicular zone. Compare this reference image with the other images of the DSIL in this blog. (Image courtesy of Dr Martinelli, California Equine Orthopedics)

Thomas's case study is a sponsored blog post in cooperation with Hallmarq Veterinary Imaging.

Watch for more in the Hallmarq-sponsored article series on The Hoof Blog, and check their social media system and especially their info-deep web site for lots more information.

To learn more about Hallmarq Veterinary Imaging and standing MRI technology for horses:

• Become a fan  of the new Hallmarq Equine MRI Facebook page;
• Follow @HallmarqMRI on Twitter;
• Subscribe to the hallmarqvetimaging channel on YouTube.com;
• Watch for a growing equine distal limb Hallmarq MRI image gallery on Flickr.com;
• Visit the Hallmarq.net web site. (Plan to spend some time there!)


MRI images used in this article were provided by Hallmarq as examples and are not the actual radiographs from Thomas's file.

This case study originally was written for an article on lameness in Horse and Hound Magazine.

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Equine Imaging: Hallmarq's Standing MRI Expertise Accessible Through Hoof Blog Alliance

This video, produced by Hallmarq Veterinary Imaging, details the procedure involved in preparing for and executing a standing MRI as practiced by Sarah E. Powell, MA, VetMB, MRCVS in the Hallmarq suite at Rossdales Equine Diagnostic Centre in Newmarket, England.

Get ready for some exciting new additions to the Hoof Blog. Over the next few weeks, the H-Blog will present information for and with the assistance of Hallmarq Veterinary Imaging, a company that is recognized as the worldwide leader in standing-MRI imaging of the horse's lower limb.

Now that 14 leading North American university and private equine hospitals are equipped with specialized Hallmarq magnetic resonance imaging (MRI) units for hoof imaging, there is a "need to know" in the horse owner, trainer, technician, therapist and farrier sectors about what this type of veterinary diagnostic imaging involves and what its value to the horse can be. Worldwide, almost 50 Hallmarq lower limb imaging suites are in use; images of almost 20,000 equine lameness cases have been archived in the company's central database. But what does that mean to a horse in my care, or in yours?

Why does a veterinarian need an MRI if a radiograph has already been taken? An MRI looks literally "into the foot" from different angles and reveals the condition of soft tissue structures, such as tendons, ligaments, and hard-to-view points like the navicular bursa. A radiograph's weaknesses are an MRI's strengths. MRI results are especially valuable for making a prognosis for a performance-related injury. (Hallmarq image)

With Hallmarq's expertise and vast database of images, we will be helping to de-mystify where, when and how MRI fits into the bigger picture of horse foot injury imaging and explaining specific foot problems that are especially well-suited for detailed soft-tissue analysis using MRI technology. Hallmarq's unit, as you will see in this video, also allows the horse to be imaged while standing, so that only sedation is required rather than subjecting the horse to the risks of general anesthesia.

That's the process, and while we all are interested in the end results, it's important to know what can be done to best prepare horses for an MRI appointment and to appreciate the valuable information that MRI might provide. Information from leading clinics and lameness specialists will provide insights and perhaps give insight to what the future may hold.

Watch for more in the Hallmarq-sponsored article series this summer, and check their social media system and especially their info-deep web site for lots more information.

To learn more about Hallmarq Veterinary Imaging and standing MRI technology for horses:

• Become a fan  of the new Hallmarq Equine MRI Facebook page;
• Follow @HallmarqMRI on Twitter;
• Subscribe to the hallmarqvetimaging channel on YouTube.com;
• Watch for a growing equine distal limb Hallmarq MRI image gallery on Flickr.com;
• Visit the Hallmarq.net web site. (Plan to spend some time there!)

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About Hoof Blog sponsored articles: From time to time, the HOOF BLOG publishes articles made possible by the sponsorship of industry partners and advertisers. These articles will always be clearly marked as sponsored content. They are developed and created by Hoofcare Publishing in collaboration with the sponsor. Only articles clearly marked as sponsored content have commercial affiliations. Sponsored content opportunities are available to companies whose programs, events or products are relevant to the educational mission of Hoofcare Publishing and the interests of its subscribers. Please email Hoofcare more information on sponsorship opportunities.