Assessment of Bone Morphology Using Standing Robotic CT in 2-Year-Old Thoroughbred Racehorses in Their First Year of Training

Introduction: Injuries of the metacarpo- and metatarso-phalangeal (MCP/MTP) joints, associated with repetitive cyclic stress, are some of the most catastrophic injuries seen in Thoroughbred racehorses. Early detection of bone injury prior to irreversible damage or breakdown 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 of the MCP/MTP joints associated with race training in young Thoroughbreds. We hypothesized that this is a useful tool for subjectively assessing adaptive and pathologic changes in bone morphology in these horses.

Materials and Methods: Forty-one 2yo TB racehorses were recruited prior to the start of training. Horses were evaluated at baseline, 6 months, and 12 months of training for lameness evaluation, effusion evaluation, rCBCT scan, and radiographs of all 4 MCP/MCT joints. Images were evaluated for sclerosis and lesions present throughout the joint.

Results: There was significant increase in sclerosis and lesion development over time, most prominently in the distal palmar/plantar condyles. Lesions were 50% more likely to develop medially.

Discussion/Conclusion: The Results coincide with what is seen post-mortem in racing thoroughbred MCP/MCT joints. The main limitations of this study were horses not being present for all time points due to relocation for training and/or racing and the lack of control over racing and training routines. By validating the use of rCBCT has a screening tool of bone morphology, we can observe the progression of pathologic changes, leading to early intervention before irreversible or potentially fatal injuries occur.

Acknowledgements: There are no conflicts of interest, project was funded by Grayson-Jockey Club Research Foundation.

Publication History

Article published online:
26 October 2022