ABSTRACT
BACKGROUND:Bilateral ovariectomy is a most commonly used method to establish an animal model of postmenopausal osteoporosis.Up to now,little is reported on the C57 mouse model of osteoporosis with calvarial critical-size defects.OBJECTIVE:To establish the C57 mouse model of osteoporosis with calvarial critical-size defects.METHODS:Thirty-six C57 mice aged 8 weeks were randomly divided into two groups:the mice in model group received bilateral ovariectomy,and the same weight of fat tissues around the ovaries of the other mice were cut as control group.At 6 weeks after modeling,the mouse femur was removed for micro-CT scan and hematoxylin-eosin staining to testify whether there is a success or failure in animal modeling.Afterwards,six mice were respectively selected from each group,and two round calvarial defects with a diameter of 4 mm were symmetrically made on the parietal bone.The defect healing was evaluated by micro-CT scan at 8 weeks after modeling.RESULTS AND CONCLUSION:At 6 weeks after modeling,the bone volume fraction,bone surface to volume ratio,trabecular thickness,trabecular number,trabecular spacing and bone mineral density in the modeling group were significantly lower than those in the control group (P ＜ 0.05).In the model group,there were loosen or fractured trabeculae,and enlarged medullary cavity.At 8 weeks after bone defects,showed no significant micro-CT changes in the defect region in both two groups.These findings implicate a success in establishing the C57 mouse model of osteoporosis with calvarial critical-size defects.