沙疗对股骨力学性能的影响及其有限元分析

Mechanical properties of therapeutic sand upon femur and its finite element analysis

目的 探讨在维医沙疗中，沙疗前后股骨力学性能的变化。方法把兔子随机分为沙疗组、对照组两组，沙疗组和对照组的兔子都有退化型关节炎，对照组兔子不进行任何形式的治疗，仅对沙疗组兔子进行沙疗实验，在沙疗完成后，取出兔子股骨做成试件并进行分组。采用NJ-100B型实验机对股骨进行拉伸和压缩强度的测定，将实验数据有限元进行分析。结果沙疗组的平均拉伸强度比对照组的平均拉伸强度要高4．54MPa，沙疗组的平均压缩强度比对照组的平均压缩强度要高22．76MPa，有关节炎病变的兔子通过沙疗其骨骼的综合强度有一定的改善（23．21MPa）。有限元分析显示，在载荷从0～924kg·m·s^-2之间变化时，长半轴的应力值总比短半轴应力值大（6．08MPa）。结论在体外不同温度加热后对骨组织的生物力学性能无明显影响。股骨离体静拉伸强度无明显下降，压缩强度比正常组有所提高。

Objective To study the mechanical properties of therapeutic sand for femur used in the Uyghur medicine. Methods Rabbits were randomly divided into the treatment group and the control group. Rabbits of both groups had arthritis. No treatment was carried out for the control group. Only sand therapy was offered for the treatment group. After sand therapy was completed, rabbits specimen were removed and grouped. The NJ-100B device was employed to measure the femur tensile and compressive strength and the analysis of finite element performed upon the experimental data. Results At different sand temperatures below 55℃, there was no significant difference in maximal stress and elastic modulus of tensile / compressive/ bending of each femur sample. Conclusion Under different temperatures, the in vitro heating has no obvious effect upon the bio-mechanical performance of bone tissues. The static tensile strength of ex vivo femur shows no obvious decline. And the compressive strengthen improves somewhat over the normal group.