Clinical effects of exercise on subchondral bone of carpal and metacarpophalangeal joints in horses.
OBJECTIVE
To determine effects of treadmill exercise on subchondral bone of carpal and metacarpophalangeal joints of 2-year-old horses.


METHODS
12 healthy 2-year-old horses.


METHODS
Horses were randomly assigned to the control (n = 6) or exercised (6) groups. Horses in the exercised group ran on a high-speed treadmill 5 d/wk for 6 months. Horses in the control group were hand walked for the same amount of time. Results of clinical, radiographic, nuclear scintigraphic, and computed tomographic examinations, and serum and synovial concentrations of biochemical markers of bone metabolism were compared between groups.


RESULTS
Exercised horses were significantly lamer at the end of the study than control horses. Radionuclide uptake in the metacarpal condyles, but not in the carpal joints, was greater in exercised horses, compared with control horses. Exercised horses also had a higher subchondral bone density in the metacarpal condyles than control horses, but such differences were not detected in the carpal bones.


CONCLUSIONS
None of the diagnostic techniques evaluated was sufficiently sensitive to detect all osteochondral damage. Computed tomography and computed tomographic osteoabsorptiometry were superior to conventional radiography for detecting small osteochondral fragments. Nuclear scintigraphy was a sensitive indicator of subchondral bone change but lacked specificity for describing lesions and discerning normal bone remodeling from damage. Newer techniques such as computed tomography may help clinicians better diagnose early and subtle joint lesions in horses prior to development of gross joint damage.
Kawcak
C E
CE
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
McIlwraith
C W
CW
Norrdin
R W
RW
Park
R D
RD
Steyn
P S
PS
D000818:Animals; D002350:Carpus, Animal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005080:Exercise Test; D006736:Horses / Q000033:anatomy & histology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011877:Radionuclide Imaging; D011897:Random Allocation; D013314:Stress, Mechanical