骨性关节炎模型兔股骨各骨质层体积与力学性能的关联性分析

目的：探讨骨性关节炎（OA）模型兔股骨各骨质层体积和力学性能的变化，阐明各骨质层体积与力学性能的关联性。方法：10只新西兰大白兔右后股骨关节腔分别在第1、5和12天注射0.3 mL•kg^-1 3%木瓜蛋白酶，建立OA模型，左后腿为正常对照组。分别在建模3 d前及建模后第7、27和37天进行4次CT扫描，将CT数据导入MIMICS软件，在MIMICS软件中提取股骨模型并获得各股骨骨质层的总体积。第4次CT扫描后，取兔左右股骨作为试件，进行三点弯曲试验，获得负载-挠度曲线。对比弹性载荷和弹性挠度，计算最大弯曲正应力。结果：与正常对照组比较，在兔股骨生长过程中，模型组兔右腿横截面惯性矩和挠度无明显变化（P>0.05），但股骨生长速度、最大抗弯强度、最大抗弯正应力、股骨硬质骨增加速度和密质骨增加速度显著降低（P<0.05），软质骨减少速度基本一致（P<0.05）。结论：OA可导致兔股骨各骨质层增加的速度和力学性能显著降低，其力学性能与各骨质层存在关联。
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Analysis on correlation between each bone layer volume of femur and mechanical properties of osteoarthritis model rabbits

Abstract:Objective
To investigate the changes of each bone layer volume and mechanical properties of osteoarthritis(OA) rabbit femur and to clarify the correlation between the each bone layer volume and mechanical properties. Methods 0.3 mL•kg^-1 3% papain were injected into the joint space of right knee of 10 rabbits on the 1st,5th and 12th days,respectively,to establish OA models (model group); the left legs of the rabbits were used as normal control group. Four times of CT scanning were performed 3 d before modeling and 7,27,37 d after modeling,then the CT data was imported into MIMICS software,the femur model was extracted in the MIMICS software and the total volume of each femur bone layer was acquired. After CT scanning for 4 times,the left and right rabbit femurs were taken as specimen. The tree-point bending test was performed and the load-deflection curves were obtained. The elastic load and the elastic deflection were contrasted and the maximum bending stress was calculated. Results Compared with normal control group,the deflection and cross-sectional moment of inertia of the right leg of the rabbits in model group had on significant changes in the rabbit bone growth process (P> 0.05); but the growth rate and maximum flexural strength and maximum bending normal stress and cortical bone growth rate and compact bone growth rate were greatly decreased ( P<0.05),and the soft bone reduce rate was　basically consistent( P<0.05). Conclusion The increasing rates of each bone layer and the mechanical properties of the femur in the rabbits with OA are significantly decreased and the mechanical properties have correlation with each bone layer.
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