2-in-1 Suspensory Desmitis Surgery Restores Western Performance Horses

Lameness in horses is not only challenging to diagnose but also to resolve. Legs are complex systems of muscle, bone, tendons, and ligaments in which injury to one structure can create a domino effect. For instance, when the proximal (upper) suspensory ligament becomes damaged and inflamed—a condition called proximal suspensory desmitis—the surrounding fascia (connective tissue) can constrict the ligament and trigger pain in what is known as compressive compartment syndrome.

In these cases equine surgeons often perform a two-in-one surgery called deep branch lateral plantar neurectomy and fasciotomy (DBLPNF). It’s a mouthful to say, but the tactical cuts release pressure from the binding fascia and derail pain signals from the plantar nerve. Until now, however, researchers hadn’t documented the surgery’s success rate in getting Western performance horses back to work.

Dane Tatarniuk, DVM, Dipl. ACVS-LA, clinical assistant professor of veterinary clinical sciences at Iowa State University, in Ames, told colleagues at the 65th Annual American Association of Equine Practitioners Convention, held Dec. 7-11 in Denver, that a recent study of 21 cases from two clinics confirms that DBLPNF surgery is a good choice for hind-limb proximal suspensory desmitis. The study included Western pleasure, reining, cutting, working cow horse, barrel racing, steer wrestling, and team roping horses. In each case, veterinarians confirmed a diagnosis of hind-limb suspensory ligament desmitis using nerve blocks and ultrasound imaging. In 12 horses, both back legs were affected.

After surgery, 86% of the horses returned to athletic use, with nine performing at their previous level or higher, while nine returned to a lower level of work. Attending veterinarians considered eight horses completely sound in follow-up exams approximately six months post-surgery. In 10 cases, owners said their horses continued to receive therapeutic joint injections to help maintain performance.

The median time from surgery to “meaningful training or riding,” was eight months, said Tatarniuk. He also correlated longer rehabilitation periods with improved outcomes. Rehab protocols—including stall rest, hand-walking, small paddock turnout, and light work—ranged from one to three months and were based on recommendations from prior studies. “Our results do suggest that longer rehabilitation could optimize return to use,” he observed.

In general, owners said they were happy with their decision to go ahead with DBLPNF surgery, with 76% stating a “high satisfaction rate.” Of the three horses in the group that didn’t return to work, one suffered an unrelated forelimb fracture and was euthanized, one improved temporarily and then regressed, and the third was never sound.

Tatarniuk said the Iowa State findings compare favorably to another retrospective study that looked at 155 English discipline and racehorses, in which 77% returned to work after hind-limb neurectomy and fasciotomy. Tatarniuk says the outcome will help Western performance horse owners and attending veterinarians make more informed decisions when considering treatment options for hind-limb proximal suspensory desmitis.