Li Hongshuai, Zhang Changqing, Zeng Bingfang
Department of Orthopaedics, 6th People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, 200233, P. R. China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2008 Mar;22(3):281-9.
To measure the changes of bone mineral density and bone micro-architecture of the femoral head that harvested from the three-foot bearing ethanol destroyed canine model for osteonecrosis of femoral head, and discuss the influences of local injection of ethanol and biomechanical loading to the structural properties of the femoral head.
Twenty-four Beagles were divided randomly into four-foot bearing canines and three-foot bearing canines. One fore-limb was fixed randomly in three-foot bearing canines. Osteonecrosis was induced in all experimental animals by local injection of 5 mL pure ethanol into one side of the femoral head. The hind limbs injected with NS were acted as control group, that of three-foot canines injected with ethanol were acted as three-foot canine group, and that of four-foot canines injected with ethanol were acted as four-foot canine group. The contralateral femoral head was injected into equal amount of NS. Animals were sacrificed at the time intervals of 1, 3, 6, and 12 weeks after the injection of ethanol. Quantitative microcomputed tomography was used to characterize changes in bone micro-architecture and bone mineral density of femoral head.
The clear three-dimensional model of trabecular bone of necrotic femoral head were obtained. There were no significant differences among 3 groups according to the time line by 1 week after ethanol injection(P > 0.05). At 3 weeks after injection of ethanol, in three-foot canine group and four-foot canine group, the volume of BMC, BMD, BVF, and BS/BV increased gradually as the distance to the drilling canal increased. There were significant differences between 3 regions (P < 0.05). At 6 weeks, in three-foot canine group and four-foot canine group, the volume of BMC, BMD,BVF, and Tb.N of region I and II decreased significantly compared with region III (P < 0.05). At 12 weeks, there are no differences among 3 groups (P > 0.05). There were significant decreases in BMD values, BVF, BS/BV, Tb.N, Tb.Sp and Tb.Th after the injection of pure ethanol. And, the changes were more and more obvious by the time line. These changes were differentiable at 3 weeks after injection of ethanol, and became obvious at 6 weeks. These changes were more obvious at the part that near the injection canal. The changes in three-foot canine group were more obvious than that in four-foot canine group.
Resorption of necrotic compact bone trabecular may weaken the structural properties of the femoral head. Moreover, remodeling and repairing process of necrotic bone trabecular may be hampered by constant biomechanical loading that presented in three-foot bearing canines, and thereby further weaken the structural properties of the femoral head. Biomechanical loading may be one of the critical reasons that lead to the collapse of femoral head.
测量从股骨头坏死的三足承重乙醇破坏犬模型获取的股骨头骨密度和骨微结构的变化，并探讨局部注射乙醇和生物力学负荷对股骨头结构特性的影响。
24只比格犬随机分为四足承重犬和三足承重犬。在三足承重犬中随机固定一条前肢。所有实验动物均通过向一侧股骨头局部注射5 mL纯乙醇诱导骨坏死。注射生理盐水的后肢作为对照组，注射乙醇的三足犬组作为三足犬组，注射乙醇的四足犬组作为四足犬组。对侧股骨头注射等量生理盐水。在注射乙醇后的1、3、6和12周时间点处死动物。采用定量微型计算机断层扫描来表征股骨头骨微结构和骨密度的变化。
获得了坏死股骨头小梁骨的清晰三维模型。乙醇注射后1周，3组之间按时间线无显著差异（P>0.05）。乙醇注射后3周，在三足犬组和四足犬组中，骨矿含量（BMC）、骨密度（BMD）、骨体积分数（BVF）和骨表面积与骨体积之比（BS/BV）随着距钻孔通道距离的增加而逐渐增加。3个区域之间存在显著差异（P<0.05）。6周时，在三足犬组和四足犬组中，I区和II区的BMC、BMD、BVF和骨小梁数量（Tb.N）与III区相比显著降低（P<
