Some osseous cyst-like lesions in the subchondral bone of the sagittal groove of the proximal phalanx were less visible on radiographs (left) than on MRI (right). | Photo: Courtesy Dr. Sarah Gold

The fetlock is a complex high-motion joint that joins the bottom end of the cannon bone to the top of the long pastern (proximal phalanx); two proximal sesamoid bones sit to the junction’s rear. The long pastern’s sagittal groove (which underlies the ridge in the bottom of the cannon bone) is a common site of injury in racehorses. Researchers have documented these issues in racing Thoroughbreds and Standardbreds, and many carry a good prognosis for return to athletic function. However, how they impact other types of horses has remained unclear.

Sarah Gold, DVM, carried out the first study evaluating MRI characteristics and outcomes of sagittal groove injuries in nonracing horses, presenting the results at the 2017 American Association of Equine Practitioners Convention, held Nov. 17-21 in San Antonio, Texas. Gold is a sports medicine veterinarian at B.W. Furlong and Associates, in Oldwick, New Jersey, and Advanced Equine Imaging of Wellington, in Florida.

Gold and colleagues reviewed medical records from January 2007 through 2016 and identified 19 Warmbloods (15 geldings and four mares) with sagittal groove injuries veterinarians had examined with MRI