Researchers Compare Joint Injection Options

Researchers Compare Joint Injection Options

Despite a high short-term success rate, only approximately 50% of horses were back in full work three months after treatment.

Photo: Alexandra Beckstett, The Horse Managing Editor

A head-to-head comparison of the corticosteroid triamcinolone and a combination of triamcinolone and hyaluronic acid (a natural articular cartilage and synovial fluid component) for horses with osteoarthritis yielded “unexpected” results, a group of Dutch researchers recently revealed.

“Veterinarians have been injecting arthritic horse joints with steroids either with or without hyaluronic acid for decades,” explained Janny C. de Grauw, DVM, PhD, from the Utrecht University Faculty of Veterinary Medicine in The Netherlands. “Many of those practitioners are under the impression that hyaluronic acid can minimize potential negative effects of steroids and that the combination provides more effective alleviation of lameness than steroids alone."

Despite the combination triamcinolone and hyaluronic acid's popularity, there is little data to support it. To that end, De Grauw and colleagues recruited 80 client-owned horses with clinical joint disease, meaning they had a lameness of at least grade 2 on a 0 to 5 scale. All included horses had been diagnosed with a lameness of one joint in one limb. The researchers assessed horses' lameness and effusion (swelling) scores at the start of the study, just before the joint was injected, and again three weeks after injection.

The researchers randomly assigned study horses to one of two treatment groups that received either 12 mg of triamcinolone or 12 mg of triamcinolone and 20 mg of a high molecular weight hyaluronic acid. Horses received a single injection and were walkedfor the first three weeks of the study.

Three weeks following injection:

  • Horses treated with triamcinolone alone had a success rate of 87.8%, meaning that the horse showed more than two lameness grades' improvement, compared to baseline; and
  • Horses treated with triamcinolone and hyaluronic acid had a success rate of 64.1%.

Three months following injection, only half of the horses in each group had returned to their previous performance level.

“These results show that despite a high short-term success rate, which surprisingly was highest for triamcinolone alone, only approximately 50% of horses in both treatment groups were back in full work three months after treatment,” said de Grauw.

The authors noted that although this study did not find any clinical benefit of adding hyaluronic acid to triamcinolone in the short-term, the reasons behind the lack of benefit remain unknown. Potential reasons could include unknown drug interactions, dilution from joint distension, or a retrograde loss of drug when both medications were administered, among others. Additionally, they noted that this study did not address any potential chondroprotective (cartilage-sparing) effects of the combination treatment.

The study, “Intra-articular treatment with triamcinolone compared to triamcinolone with hyaluronate: A randomized open-label multicenter clinical trial in 80 lame horses,” was published in the Equine Veterinary Journal

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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