Objective—To determine the accuracy and precision
of dual energy x-ray absorptiometry (DEXA) for measuring
bone mineral density in horses in situ.
Sample Population—12 randomly selected forelimbs
from 12 horses.
Procedure—Metacarpi were scanned in 2 planes and
DEXA measurements obtained for 6 regions of interest
(ROI). Each ROI was isolated and bone density
measured by Archimedes' principle. Linear regression
analysis was used to determine the correlation
between the 2 measurements at each ROI. An additional
metacarpus was measured 10 times to determine
the coefficient of variation for both techniques.
Results—Dual energy x-ray absorptiometry and bone
density were significantly associated at multiple ROI.
The addition of age, weight, and soft tissue or bone
thickness improved these associations. Repeated
measurements had a low coefficient of variation.
Conclusions and Clinical Relevance—Dual energy
x-ray absorptiometry can be used to accurately and
precisely measure the bone density in the equine
metacarpus. Dual energy x-ray absorptiometry
appears suitable for serial in vivo measurement of
bone density of the equine metacarpus. Dual energy
x-ray absorptiometry may be used for studies to evaluate
the effects of diet or drugs on bone density or
density changes from bone remodeling that develop
prior to stress fractures. ( Am J Vet Res 2001;