Effect of ovariectomy combined with hormone injection on bone density and biomechanical performance of sheep proximal femur / 重庆医学

ABSTRACT

Objective To evaluate the effecof bilateral ovariectomy combined with hormone injection on the bone mineral density and biomechanical property of sheep proximal femu.Method16 healthy adulsheep were divided into the sham operation group (n=8) and the experimengroup (n=8) randomly .Bilateral ovariewere only exposed in the sham operation group .The ex-perimengroup waperformed bilateral ovariectomy (OVX) and began to conducthe intramusculainjection of methylprednisolone (0 .45 mg · kg -1 · d-1 ) aftepostoperative 1 month fo10 month.The bone density (BD) of all sheep proximal femuwameas-ured before OVX and in postoperative 1 yea.The compression tesand the axial pullouteswere performed to evaluate biome-chanical property of postoperative 1 yeaproximal femu.ResultBD of proximal femubefore surgery had no statistically signifi-candifference between the two group,and which in the sham operation group had no statistically significandifference between before and aftesurgery (P＞0 .05) .BD of proximal femuin postoperative 1 yeain the experimengroup wasignificantly de-creased and significantly lowethan thain the sham operation group (P＜0 .05) .The maximal compression stresand the energy absorption value in the experimengroup were significantly lowethan those in the sham operation group with statistically signifi-candifferences(P＜0 .05);the maximal axial pulling force and the energy absorption value in the experimengroup were signifi-cantly lowethan those in the sham operation group with statistically significandifference (P>0 .05) .Conclusion The method of bilateral ovariectomy combined with hormone injection can significantly decrease BD and biomechanical intensity of sheep proximal femu.