Objective—To determine those bones in the distal
aspect of the limbs of Greyhounds with fatigue fractures
that have the greatest left-to-right differences in
bone-mineral density (BMD).
Sample Population—Limbs obtained from 20
Procedure—Dual-energy x-ray absorptiometry (DXA)
of the distal aspect of each limb and isolated bones
from 10 dogs with a fracture of the central tarsal bone
(CTB) of the right pelvic limb was performed. Highresolution
scanning was performed on excised
bones, and BMD measurements of CTB also were
obtained from limbs of dogs without a CTB fracture.
Results—The BMD of the accessory carpal bone and
calcaneus was not significantly different from the
BMD of those bones in the contralateral limb.
Although BMD of the CTB of the entire right pelvic
limb and isolated bones from dogs with a CTB fracture
was lower, compared with values for the entire
left pelvic limb, values for isolated CTB from dogs
without a CTB fracture were not significantly different.
Metacarpal or metatarsal and thoracic or pelvic
limb significantly affected BMD for measurements of
the entire limb and isolated bones. Left-to-right differences
in BMD were greatest for metacarpal 5.
Conclusions and Clinical Relevance—Asymmetric
adaptive remodeling of metacarpal 5 can be detected
by DXA. The potentially confounding effects of CTB
fracture and unknown racing history made it difficult
to interpret BMD changes in the CTB of these specimens.
Densitometry could be developed as an in vivo
assessment for risk of fractures in racing
Greyhounds. (Am J Vet Res 2000;61:1214–1219)