This X ray illustrates the typical fragment appearance. Fragments (arrows) were most commonly found in the hind limbs at the dorsomedial (front and inside) aspect of the pastern joint. | Photo: Courtesy Dr. Christine Moyer

Veterinarians regularly remove osteochondral fragments—essentially, cartilage-covered bone chips—from certain horse joints, including fetlocks and hocks, using relatively straightforward arthroscopic procedures. Less frequently they encounter bone chips in the pastern joint, said Christine Moyer, DVM, MS, an equine veterinarian in Cave Creek, Arizona.  Consequently, there’s less research data available on pastern bone chip removal and patient recovery.

At the 2018 American Association of Equine Practitioners Convention, held Dec. 1-5 in San Francisco, California, Moyer presented results from a study in which she and colleagues described pastern osteochondral fragment removal and evaluated how well Thoroughbred racehorses performed following this surgery.

The team pulled the records of 56 horses that had pastern joint chips removed arthroscopically at a single veterinary hospital by one of four surgeons over a 15-year period; of those, 39 were Thoroughbreds (aged 4 months to 4 years). Then, they collected race data for the Thoroughbreds and 169 of their maternal siblings—age-matched controls in this study—to compare performance