Study Links Bone Loss to Proximal Sesamoid Bone Fractures in California Racehorses A recent study by Sarah Shaffer, International Equine Veterinarian Hall of Fame member Dr. Susan Stover and colleagues at the J.D. Wheat Veterinary Orthopedic Research Laboratory at the UC Davis School of Veterinary Medicine sought to characterize bone abnormalities that precede proximal sesamoid bone (PSB) fractures and determine if pre-existing abnormalities are associated with these fractures.