Associations between the radiographic appearance of vascular channels in proximal sesamoid bones, their microstructural characteristics and past racing performance in Thoroughbreds.

Background: Abnormalities in vascular channel appearance within the proximal sesamoid bone (PSB) are the most common findings in Thoroughbred yearling presale radiographs and are often evaluated on radiographs of adult racehorses. Despite this, their pathogenesis and clinical significance are poorly understood, and associations with racing performance are inconsistent.

Objectives: To determine microstructural characteristics of the PSBs associated with the radiographic appearance of vascular channels using microcomputed tomography (µCT) and to determine associations with past racing performance in mature horses.