维医学埋沙疗法对膝关节骨性关节炎兔股骨骨力学特性的影响

目的 探讨维医学埋沙疗法对膝关节骨性关节炎（OA）兔股骨骨力学特性的影响。方法 16只新西兰大白兔经右后股骨关节腔注射木瓜蛋白酶建立OA模型后分为沙疗组和对照组（n=8）。沙疗组在模拟的吐鲁番沙疗场给予沙疗，2次/d，每次30 min，连续4周；对照组不给予沙疗。CT扫描股骨并采集数据，采用交互式的医学影像控制系统（MIMICS）进行分析，比较两组各骨质层（软质骨、密质骨和硬质骨）的体积。对两组动物的左右后股骨进行离体三点弯曲试验，获得负载-挠度曲线，对比承载载荷和挠度，计算骨横截面惯性矩、最大弯曲正应力和最大剪切应力。归纳和对比两组CT扫描数据和三点弯曲试验结果。结果 各骨质层的CT扫描数据分析结果显示：对照组硬质骨有向密质骨和软质骨转化的趋势，沙疗组软质骨向密质骨和硬质骨转化较为明显。三点弯曲试验结果显示：沙疗组股骨断面的形态学参数均显著低于对照组（P〈0.05），沙疗组股骨断面的最大承载载荷、最大弯曲正应力及最大剪切应力均显著高于对照组（P〈0.05），两组间横截面惯性矩和挠度的差异无统计学意义（P〉0.05）。结论 维医学埋沙疗法对成年OA兔股骨的骨质层体积分布及力学性能有良性影响。

Effects of Uygur sand therapy on bone mechanical properties of femurs of rabbits with knee osteoarthritis

Objective To investigate the effects of Uygur sand therapy on bone mechanical properties of femurs of rabbits with knee osteoarthritis （OA）. Methods The OA model was established by injecting papain in right posterior femoral articular cavity of 16 New Zealand rabbits. Rabbits were then divided into the sand therapy group （n=8） and control group （n=8）. The sand therapy group underwent the sand therapy in a place that simulated the Turpan sand therapy field, 2 times per day, 30 min per time for 4 weeks. The control group did not receive the sand therapy. Femurs of rabbits were scanned by CT and data was collected. Interactive medical image control system （MIMICS） was used to analyze and compare the volume of each bone layer （soft bone, compact bone, and cortical bone） of two groups. The three point bending test was conducted in vitro for the left and right posterior femurs of rabbits of two groups to obtain the load-deflection curve. The cross sectional moment of inertia, maximum bending normal stress, and maximum shear stress were calculated by comparing the load and deflection. The data of CT scans and results of three-point bending tests were summarized and compared. Results The analytical results of the CT scan data of each bone layer showed that the cortical bone of the control group tended to transfer to the compact bone and soft bone, while the soft bone of the sand therapy group significantly transferred to the compact bone and cortical bone. The results of three-point bending test showed that morphological parameters of the femur section of the sand therapy group were significantly lower than those of the control group （P〈0.05）. The maximum load, maximum bending normal stress, and maximum shear stress of the femur section of the sand therapy group were significantly higher than those of the control group （P〈0.05）. The differences of the cross sectional moment of inertia and deflection of two groups were not statistically significant （P〉0.05）. Conclusion The sand therapy has positive effects on the volume distribution of bone layer and mechanical properties of femurs of adult OA rabbits.