“Historically, some people have thought that Western performance horses have a poorer prognosis after stifle arthroscopy than horses in other sport horse disciplines,” Laurie Goodrich, DVM, PhD, Dipl. ACVS, professor of orthopedics and Interim Director of the Orthopedic Research Center at Colorado State University’s (CSU) Department of Clinical Sciences, told peers during the 65th American Association of Equine Practitioners Convention, which is currently underway in Denver.
But is it true?
“We really questioned that,” she said.
Goodrich credited Annette McCoy, DVM, PhD, Dipl. ACVS, an assistant professor of equine surgery at the University of Illinois, who began the study with the CSU team when she was a surgery resident, as the driving force behind this study to predict long-term outcomes for Western performance horses post-stifle-surgery. How likely are they to return to the performance arena?
The study team followed 82 equine athletes for two or more years after arthroscopy. Their portfolio included 38 cutting horses, 13 reining horses, 13 Western pleasure horses, and 18 horses identified as “other,” a catch-all category that included barrel racers, competitive trail horses, roping horses, cow horses, halter, and versatility ranch horses.
The researchers assessed each animal’s lameness, pre- and postoperative procedures and therapies, and health, including radiographs and ultrasound images. “They were analyzed for their association with return to athletic performance as the primary outcome of interest,” Goodrich said.
“Approximately 40%, or 32 horses, returned to their intended use after stifle arthroscopy,” she continued. “We were happy about that, because it was similar to the Cohen et al study done (at the University of Pennsylvania) that had 38% of horses return to previous levels of function.”
Interestingly, said Goodrich, most of the horses included in the University of Pennsylvania stifle arthroscopy study were Thoroughbreds or Warmbloods, compared to the 64 Quarter Horses, 12 Paints, and a “smattering” of other breeds represented in the CSU study.
“We also analyzed postoperative therapies, and we had a fair amount: intra-articular Vetalog (a corticosteroid), IRAP (interleukin-1 receptor antagonist protein), and stem cells, as well as systemic Adequan, and nonsteroidals,” she said. “None of the therapies in this study affected the odds of the horses returning to intended use.”
Nonetheless, Goodrich said the study supports three main takeaways:
- The prognosis for Western performance horses following stifle arthroscopy is similar to that of other sport horse disciplines and activities.
- Increasing age, increasing duration of lameness, and a higher degree of lameness and/or the presence of partial-thickness cartilage lesions reduce a horse’s likelihood of returning to work.
- Discipline within the Western sport horse categories was not a significant factor in a horse’s ability to return to performance.