ANALYTICAL CLINICAL STUDIES
Pathological and clinical features associated with palmar/plantar osteochondral disease of the metacarpo/metatarsophalangeal joint in Thoroughbred racehorses
Article first published online: 19 FEB 2013
© 2012 EVJ Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Equine Veterinary Journal
Volume 45, Issue 5, pages 587–592, September 2013
How to Cite
Pinchbeck, G. L., Clegg, P. D., Boyde, A. and Riggs, C. M. (2013), Pathological and clinical features associated with palmar/plantar osteochondral disease of the metacarpo/metatarsophalangeal joint in Thoroughbred racehorses. Equine Veterinary Journal, 45: 587–592. doi: 10.1111/evj.12036
- Issue published online: 2 AUG 2013
- Article first published online: 19 FEB 2013
- Accepted manuscript online: 24 DEC 2012 07:00AM EST
- Manuscript Accepted: 7 DEC 2012
- Manuscript Received: 13 MAR 2012
- Horserace Betting Levy Board and the Hong Kong Jockey Club
- metacarpo/metatarsophalangeal joint;
- palmar/plantar condyle;
- palmar/plantar osteochondral disease
Reasons for performing study
Palmar/plantar osteochondral disease (POD) of the metacarpo/metatarsophalangeal (Mc/MtPh) joints is common in Thoroughbred racehorses, but there is little information on predilection sites, associated pathologies and clinical signs.
To describe the distribution of POD at post mortem examination and to examine the association of POD with other pathologies and clinical histories.
The Mc/MtPh joints of 102 Thoroughbred racehorses were examined post mortem. Gross pathology of associated osteochondral elements, suspensory ligament and flexor tendons was recorded. Clinical data were extracted from computerised records. Relationships between all Mc/MtPh joint pathologies, clinical data and grade of POD in each condyle were determined using multilevel, ordinal logistic regression models.
Palmar/plantar osteochondral disease was recorded (grade 1–3 in at least one condyle) in 80.4% (95% confidence interval 71–88) of horses. The grade of POD was significantly higher in the forelimb, where the medial condyle had higher grades, than in the hindlimb, where the POD grade was higher in the lateral condyle. There was a significant positive relationship between POD grade and multiple other joint pathologies, whereas grades of linear fissures had a negative relationship with grade of POD. There was no relationship between grade of POD and tendon and suspensory ligament gross pathology, although horses with a history of tendon injury had significantly lower POD grades. Horses that had a clinical history of a Mc/MtPh joint problem had higher POD grades. In addition, horses that had been retired from racing for more than 2 months at the date of death had significantly lower POD grades.
Conclusions and potential relevance
Palmar/plantar osteochondral disease has specific predilection sites. Horses with a clinical history of Mc/MtPh-associated lameness had higher POD grades, whereas those with a history of superficial digital flexor tendon injury and retired horses had lower grades. The progression of POD and its ability to heal requires further evaluation.