University of Pennsylvania New Bolton Center Boonton Township, New Jersey
Prospective, Longitudinal Assessment of Bone Morphology Using Standing, Robotic Cone-Beam Computed Tomography (rCBCT) in Two-Year-Old Thoroughbred Racehorses in Their First Year of Training. Ciamillo SA, Wulster KB, Richardson DW, Stefanovski D, Ortved KF. University of Pennsylvania, New Bolton Center, Kennett Square, PA.
Fetlock joints are the most common site of catastrophic injuries in Thoroughbred racehorses and are preceded by maladaptive stress remodeling secondary to excessive cyclic loading. Early detection of pathology prior to irreversible damage or failure is essential. The objective of this study was to investigate the use of standing, robotic cone-beam CT (rCBCT) for assessing changes in bone morphology associated with race training in young Thoroughbreds. We hypothesized that subchondral sclerosis would increase in MC/MT3 palmar/plantar condyles and the prevalence of bony lesions would increase with time. Forty-one two-year-old Thoroughbreds were recruited. Standing rCBCTs of all four fetlock joints were obtained at zero months (start of training), six months, and 12 months. Horses were evaluated for lameness and fetlock effusion. Subchondral sclerosis was measured on standardized CT reconstructions and CTs were examined for lesions in MC/MT3, proximal P1 and the sesamoid bones. Sclerosis was significantly increased in the medial condyles of front and hind fetlocks from zero to six months and in the lateral condyles of hind fetlocks from zero to six months. Overall, the presence of lesions increased overtime, especially in the palmar/plantar condyles. Subchondral sclerosis and bone pathology both increase with training. Longitudinal evaluation of horses in training may facilitate prevention of severe injury or catastrophic failure of the bone. The main limitations of this study included attrition and lack of control over racing and training routines. Standing rCBCT has the potential to be used as a screening tool to ideally prevent more severe bony injuries from occurring.