背景:双膦酸盐(BP)在临床上可以治疗骨质疏松和预防骨质疏松性骨折。然而,BP对皮质骨和骨小梁骨的微观结构和力学性能的影响很少被关注,分开。
方法:在本研究中,BP用于干预去卵巢雌性SD大鼠。股骨显微CT图像用于测量结构参数并重建感兴趣体积的3D模型。测量皮质骨和骨小梁的结构参数,并利用微观有限元分析对力学性能进行了预测。
结果:皮质骨的形态结构参数和机械性能与正常,去卵巢(sham-OVX)和BP干预组。然而,BP可以显着提高骨体积分数(BV/TV)和小梁分离(Tb。SP)在股间髁(IT)中(sham-OVXvs.BP,p<0.001),对股骨内侧和外侧髁的BV/TV无显著影响(MT,LT).同样,BP可以显着影响IT的有效模量(sham-OVX与BP,p<0.001),MT和LT无显著差异。此外,结构参数与有效模量呈良好的线性相关关系。
结论:在短时间内,BP干预和骨质疏松对皮质骨的影响不明显。BP对非主要负重区(IT)骨小梁的影响是有价值的,而对于骨质疏松症,主要承重区域(MT,LT)可以通过运动补偿提高骨小梁的结构质量和机械强度。
BACKGROUND: Bisphosphonate (BP) can treat osteoporosis and prevent osteoporotic fractures in clinical. However, the effect of BP on microstructure and mechanical properties of cortical and trabecular bone has been taken little attention, separately.
METHODS: In this study, BP was used to intervene in ovariectomized female SD rats. The femoral micro-CT images were used to measure the structural parameters and reconstruct the 3D models in volume of interest. The structural parameters of cortical and trabecular bone were measured, and the mechanical properties were predicted using micro-finite element analysis.
RESULTS: There was almost no significant difference in the morphological structure parameters and mechanical properties of cortical bone between normal, ovariectomized (sham-OVX) and BP intervention groups. However, BP could significantly improve bone volume fraction (BV/TV) and trabecular separation (Tb.SP) in inter-femoral condyles (IT) (sham-OVX vs. BP, p < 0.001), and had no significant effect on BV/TV in medial and lateral femoral condyles (MT, LT). Similarly, BPs could significantly affect the effective modulus in IT (sham-OVX vs. BP, p < 0.001), and had no significant difference in MT and LT. In addition, the structural parameters and effective modulus showed a good linear correlation.
CONCLUSIONS: In a short time, the effects of BP intervention and osteoporosis on cortical bone were not obvious. The effects of BP on trabecular bone in non-main weight-bearing area (IT) were valuable, while for osteoporosis, the main weight-bearing area (MT, LT) may improve the structural quality and mechanical strength of trabecular bone through exercise compensation.