RESEARCHERS working with the University of Kentucky’s Gluck Equine Research Centre examined 46 thoroughbred yearlings with carpal osteochondral fragments, commonly called knee chips. These involved the radial or intermediate carpal bones.

Of the affected horses, 26 underwent arthroscopic removal before sale, while 20 were managed without surgery. Racing records were then followed.

Published in Equine Veterinary Journal, the retrospective study compared these horses with 138 yearlings matched by sire and year, which had no radiographic abnormalities. Horses treated surgically had significantly higher odds of establishing a racing career than those managed conservatively. The untreated group also performed significantly worse overall than controls in sales and racing measures.

Radiographic abnormalities

Surgically-treated horses showed no significant differences from controls in sale price or total winnings. However, both groups with chips recorded fewer starts and racing seasons than controls.

The findings do require caution however. Most direct comparisons between treated and untreated horses did not reach statistical significance.

Individual assessment

The study was small, drew on one veterinary centre and lacked follow-up X-rays during racing careers. As an observational study, it cannot establish that surgery caused better outcomes.

For breeders and buyers, the research supports a more individual assessment of affected yearlings, while leaving important questions about the benefits of surgery for larger studies to answer.