Fractures: Beyond the Limbs, Part 2

Monika L Haskell
Feb 18, 2019
3 min read

Pelvic Fractures

External trauma or a fall can cause these fractures. They can affect any part of the pelvis, but veterinarians most commonly see damage to the tuber coxae (point of the hip) when horses run into objects such as fence posts or narrow doorways. Racehorses and sporthorses might incur another type of injury: fractures involving the wing of the ilium (the largest of the three pelvis bones) secondary to cyclic loading and strain during performance. These can begin as microfractures and progress to nondisplaced fractures and eventually large displaced injuries.

“Pelvic fractures in adults can be difficult to diagnose, have an extended convalescence, and in some cases are life-threatening, as displaced fracture fragments can lacerate major blood vessels in close proximity to the pelvis,” Tull says.

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Horses with pelvic fractures can exhibit a variety of clinical signs—some as vague as an abnormal hind stance. Lamenesses can range from sudden severe hind-limb lameness, inability to stand, and reluctance to move, to mild and intermittent unsoundness. The bony structures of the tuber coxae or the tuber sacrale at the top of the rump might appear asymmetric. Symmetric or asymmetric gluteal muscle atrophy (wasting) might develop over time.

Due to the size of the musculature surrounding the pelvis, it can be challenging to diagnose these fractures using radiographs. Manufacturers have recently developed high-powered radiograph equipment that can capture an image of the horse’s pelvis while he is awake and standing. But currently, these advanced diagnostics are only available at large equine hospitals or universities. Ultrasonography through the gluteal muscles or the rectum, on the other hand, allows the veterinarian to identify pelvic fractures readily, and the equipment is portable and commonly available in equine practice.

Pelvic fracture treatment involves long-term stall rest, with recovery length and return to function dependent on the fracture’s location. “If the horse can be managed comfortably with stall rest and anti-inflammatories, judgment on future soundness should be reserved until several months into treatment,” Tull says. Monitor broodmares that have previously fractured their pelvis closely during foaling, as the healed injury might have caused deformation or narrowing of the birth canal, setting them up for a difficult birth.

Fractured Spinous Processes

Horses can roll from side to side without injury, but a fall or flip backward can crush or fracture the spinous processes of the thoracic vertebrae that make up the withers. These lesions might not be obvious at first, with some horses showing signs of mild discomfort, forelimb lameness, or reluctance to move their head and neck. Deformation of the withers and pain on palpation are evident in more obvious cases.

Veterinarians base their diagnoses on radiographs as well as nuclear scintigraphy. In many of these cases, especially when the fracture site is stable, conservative management comprised of anti-inflammatories and stall rest will suffice. If the fractures are displaced and unstable in the surrounding tissue, or if the spinous processes begin to touch one other (also known as kissing spines) as they heal, a surgeon can remove the fractured pieces.

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“Additionally, if there is a wound involved, as with any other open fracture, there is a great risk of infection and surgery is indicated,” says Morello. The prognosis for the return to function is good, though a perfect cosmetic outcome might not be possible. “Depending on where the fracture is it may heal on its own, but performance horses may require removal of fracture fragments to preserve long-term function,” she adds.

Take-Home Message

So while distal limbs are the most common equine fracture sites, several other bony structures can be damaged from trauma or cyclic wear. Knowing where these sites are and their presenting clinical signs will help you recognize problems in your own horses sooner, leading to faster treatment and a better potential outcome.

Happy Riding!