人体内、外侧半月板生物材料力学特征及比较的实验研究

Comparative Study of Biological Material Mechanical Characteristics for Medial and Lateral Human Meniscus

目的:通过对人体膝关节内侧半月板与外侧半月板多部位、多切面的力学实验,研究其生物材料力学的特征,对比其差异,有助于分析该结构发生损伤的机理,为损伤后的治疗、修复、人工材料置换等提供实验参考依据。方法:取右侧膝关节无病变,年龄在20～45岁之间的成年男性内、外侧半月板各6块。将半月板分为前角、体部和后角3部分,再对前角与后角进行水平面、额状面冰冻切片,体部进行水平面、矢状面冰冻切片,制作成标准试件。使用上海大学力学实验中心"生物材料力学性能测试系统"完成"一维拉伸试验"和"应力松弛试验"。实验数据经统计学处理,进行:1)内、外侧半月板前角额状面及水平面比较;2)内、外侧半月板后角额状面及水平面比较;3)内、外侧半月板体部矢状面及水平面比较。结果:1)内、外侧半月板瞬时弹性响应比较,前者的前、后角均显著大于后者,前者的体部显著小于后者(P≤0.05);2)内、外侧半月板各部位、各切面应力松弛率比较均无显著性差异(P>0.05);3)外侧半月板不同部位、不同切面中有4项抗拉伸能力指标显著低于内侧半月板(P≤0.05)。结论:1)外侧半月板前角与后角、内侧半月板体部粘弹性较差,抵抗瞬时外力的能力较弱,从生物材料的角度看可能在承受突然较强的负荷时容易发生损伤;2)内、外侧半月板各部位、各切面调整负荷的能力基本相同,运动时若注意关节运动幅度适度、准备活动充分,应能够避免因负荷不均造成的损伤;3)外侧半月板较内侧半月板抗拉伸能力弱,可能是其急慢性损伤更为多见的生物材料力学原因之一。

Objective：To conduct the multiple-section and multiple-slice biological material mechanical experimental study on the medial and lateral meniscus of human knee,compare the difference in the mechanical characteristics,and analyze the injury mechanism in order to provide experimental references for treatment,repair or artificial material replacement after injury occurrence.Method：Take twelve medial and lateral meniscuses,six each from the right no-lesion knees of adult males of ages between 20 to 45 years old.Divide meniscuses into the anterior horn,the body,and the posterior horn.Frozenly sectioning the anterior horn and the posterior horn along the horizontal plane and the frontal plane,and sectioning the body along the horizontal plane and the sagittal plane to make standard testing specimen.Use the biological materials mechanical characteristics testing system,located at the Mechanical Experimental Center of Shanghai University,to conduct the one-dimensional tensile and stress relaxation experiments.The experimental data are statistically processed and the medial and lateral meniscuses are compared for 1） the horizontal plane and the coronal plane of the anterior horn;2） the horizontal plane and the coronal plane of the posterior horn;3） the sigittal plane and the horizontal plane of the body.Results：1） The instantaneous elastic response of the anterior horn and the posterior horn of the inside meniscus is significantly greater than that of the outside meniscus（P≤0.05）,and the instantaneous elastic response of the body of the outside meniscus is significantly greater than that of the inside meniscus（P≤0.05）;2）There is no significant difference in the stress relaxation rate for each section of the inside and outside meniscus（P0.05）;3） Four items of tensile capacity are significantly high（P≤0.05）.Conclusion：1）The instantaneous elastic responding index of the anterior horn and the posterior horn of the medial meniscus is significantly larger than that of the lateral meniscus,while index of the medial body is significantly smaller than that of the lateral.（P≤0.05）;2） The ability to adjust load capacity is substantially the same for each section of the medial and lateral meniscuses.If the joint range of motion is moderate and preparations are fully made,it should be able to avoid the damage caused by the uneven load;3）The anti-tensile ability of the lateral meniscus is weaker than that of the medial meniscus,which might be one of the reasons for common urgent and chronic injury from the perspective of bio-mechanics of materials.