Das ovariektomierte und glukokortikoid-behandelte Schaf als Großtiermodell für die Osteoporoseforschung

The aim of this study was to evaluate and establish a large animal
model of osteoporosis by a combination of ovariectomy and steroid
treatment. A variety of densitometric, morphometric and
biomechanical methods were used to quantify changes in ovine bone
under estrogen-deficiency and glucocorticoid treatment. With DXA we
monitored the progression of the loss of bone mineral density of
integral bone at the central and the load-bearing skeleton.
Peripheral QCT was employed to determine the different respons es
of trabecular and integral bone. High-resolution µCT-images allowed
the evaluation of precise morphometrical parameters.
Histomorphometric analyses provided information about newly formed
osteoid. Stiffness and strength of trabecular bone were assessed by
uniaxial compression tests. For all these examinations we utilized
integral or trabecular bone from various skeletal locations. The
results of this study showed that a combination of ovariectomy and
glucocorticoid treatment leads to osteopenia in sh e ep. Bone
mineral density of integral bone was reduced during glucocorticoid
treatment and returned to normal values thereafter. However, loss
of bone mineral at trabecular sites was not reversible. Corticoid
treatment also affected the microarchitecture of trabecular bone:
bone volume, bone surface and trabecular thickness differed from
the control group. However, trabecular number did not change under
steroid treatment. Bone stiffness and strength of trabecular bone
of corticoid treated animals were m arkedly reduced. These results
showed the suitability of the ovariectomized and glucocorticoid
treated sheep as an animal model in osteoporosis research. It could
be used to develop new orthopaedic techniques or to test prosthetic
designs or implants for the treatment of osteoporotic fractures.