Post mortem evaluation of palmar osteochondral disease (traumatic osteochondrosis) of the metacarpo/metatarsophalangeal joint in Thoroughbred racehorses.
BACKGROUND
Thoroughbred racehorses are commonly affected by subchondral bone injury, but the exact prevalence and the distribution of palmar/plantar osteochondral disease (POD) lesions are unknown. The relationship between pathologies has not been elucidated, although it is widely accepted that POD is a manifestation of traumatic overload arthrosis.


OBJECTIVE
There is an association between grade of POD and other pathologies affecting the third metacarpal and metatarsal (MC/MTIII) condyles (wear lines, cartilage loss, marginal remodelling, dorsal impact injuries and linear fissures).


OBJECTIVE
To evaluate the pathology found affecting the distal MC/MTIII condyles of Thoroughbred racehorses at post mortem examination, to describe the prevalence and distribution of POD lesions within a population of racing Thoroughbreds and to determine relationships between pathologies of the distal condyles of the third metacarpal and metatarsal bones.


METHODS
The metacarpo/metatarsophalangeal joints of 64 Thoroughbred racehorses were examined at routine post mortem examination and graded for third metacarpal and metatarsal condylar pathology. Associations between pathologies were determined.


RESULTS
POD had a within horse prevalence of 67%. There was a significant linear relationship between grade of POD and grades of wear lines, cartilage ulceration and dorsal impact injuries. There was a significant relationship, but this was not linear, between grade of POD and grade of linear fissures. Using ordinal logistic regression, compared to condyles with grade 0 or grade 2 linear fissures, condyles with grade 1 linear fissures were found to be more likely to have a lower POD grade.


CONCLUSIONS
POD can be considered to be a manifestation of traumatic overload arthrosis, but the role of subchondral bone adaptation is complex and warrants further investigation.
Barr
E D
ED
Division of Veterinary Clinical Science, University of Liverpool, Leahurst, Neston, Cheshire, UK.
Pinchbeck
G L
GL
Clegg
P D
PD
Boyde
A
A
Riggs
C M
CM
D000818:Animals; D018409:Foot Injuries / Q000473:pathology / Q000662:veterinary*; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses; D008297:Male; D055034:Osteochondrosis / Q000473:pathology / Q000662:veterinary*