Yang Chengwei, Yang Xinle, Lan Xu, Zhang Hong, Wang Ming, Zhang Yaqiang, Xu Yajie, Zhen Ping
Department of Spine Surgery, the 940th Hospital of Joint Logistics Support Force of Chinese PLA, Lanzhou Gansu, 730050, P.R.China.
Department of Spine Surgery, the 940th Hospital of Joint Logistics Support Force of Chinese PLA, Lanzhou Gansu, 730050,
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2019 Feb 15;33(2):232-238. doi: 10.7507/1002-1892.201807085.
To clarify the structure and biomechanical characteristics of the dura mater of the cervical, thoracic, and lumbar segments of sheep, in order to provide a theoretical reference for the study of artificial dura mater.
Five adult male white sheep were sacrificed. The dura mater of C , T , and L planes were obtained. The histological HE staining was used to observe the internal structure and the thickness of dura mater; the inner and outer surfaces morphology of the dura was observed by scanning electron microscopy (SEM); transmission electron microscopy (TEM) was used to observe the internal structure of dura mater and to measure the diameter of collagen fibers in each part of dura mater. The dura mater of C , C , T , T , L , and L planes were taken for uniaxial biomechanical test, and modulus of elasticity, tensile strength, and elongation at break were measured.
HE staining showed that the thickness of the cervical, thoracic, and lumbar dura mater gradually decreased, and the thickness of the dura mater was (268.19±15.91), (198.16±27.25), (103.74±21.54) μm, respectively, and the differences were significant ( <0.05). SEM observation showed that there were more collagen fibers and fewer cells on the inner surface of the dura mater, while more cells were distributed on the outer surface, and the cells on the inner and outer surface were stretched along the longitudinal axis. TEM observation showed that the collagen fibers in the dura mater were interlaced and arranged in layers. The collagen fibers in the lamina were arranged in the same direction, and the collagen fibers between the lamina were arranged vertically. The diameters of collagen fibers in the cervical, thoracic, and lumbar dura mater were (68.04±21.00), (64.54±20.64), (60.36±19.65) nm, respectively, and the differences were not significant ( >0.05). Uniaxial biomechanical tests results showed that there was no significant difference in modulus of elasticity, tensile strength, and elongation at break between the axial and transverse dura mater of the cervical dura mater ( >0.05); the axial data of thoracic and lumbar segments were significantly larger than the transverse data ( <0.05). The axial modulus of elasticity, tensile strength, and elongation at break of the dura mater of the cervical, thoracic, and lumbar dura mater were significantly different ( <0.05) from the transverse ones, and showing a decreasing trend. Among them, the ratio of axial and transverse modulus of elasticity of cervical and thoracic dura were significantly smaller than that of lumbar segment ( <0.05), and there was no significant difference between cervical segments and thoracic segments ( >0.05).
The thickness of dura mater in sheep decreased gradually from head to tail. There are more collagen fibers and fewer cells on the inner surface of dura mater, while the outer surface of dura mater is covered by cells. The collagen fiberboard layers in the dura mater are arranged alternately, and have obvious anisotropic biomechanical characteristics, and the anisotropic biomechanical characteristics get more significant from the head to the tail.
阐明绵羊颈、胸、腰段硬脑膜的结构及生物力学特性，为人工硬脑膜的研究提供理论参考。
选取5只成年雄性白色绵羊处死后，获取C、T、L平面的硬脑膜。采用组织学HE染色观察硬脑膜的内部结构及厚度；通过扫描电子显微镜（SEM）观察硬脑膜内、外表面形态；利用透射电子显微镜（TEM）观察硬脑膜的内部结构并测量硬脑膜各部位胶原纤维直径。取C、C、T、T、L、L平面的硬脑膜进行单轴生物力学测试，测量弹性模量、拉伸强度及断裂伸长率。
HE染色显示，绵羊颈、胸、腰段硬脑膜厚度逐渐减小，硬脑膜厚度分别为（268.19±15.91）、（198.16±27.25）、（103.74±21.54）μm，差异有统计学意义（<0.05）。SEM观察显示，硬脑膜内表面胶原纤维较多、细胞较少，外表面细胞分布较多，内、外表面细胞均沿纵轴伸展。TEM观察显示，硬脑膜内胶原纤维相互交织成层状排列。板层内胶原纤维同向排列，板层间胶原纤维垂直排列。颈、胸、腰段硬脑膜胶原纤维直径分别为（68.04±21.00）、（64.54±20.64）、（60.36±19.65）nm，差异无统计学意义（>0.05）。单轴生物力学测试结果显示，颈段硬脑膜轴向与横向的弹性模量、拉伸强度及断裂伸长率差异无统计学意义（>0.05）；胸段和腰段轴向数据显著大于横向数据（<0.05）。颈、胸、腰段硬脑膜轴向弹性模量、拉伸强度及断裂伸长率与横向相比差异有统计学意义（<0.05），且呈递减趋势。其中，颈段和胸段硬脑膜轴向与横向弹性模量比值显著小于腰段（<0.05），颈段与胸段之间差异无统计学意义（>0.05）。
绵羊硬脑膜厚度自头端至尾端逐渐减小。硬脑膜内表面胶原纤维较多、细胞较少，外表面被细胞覆盖。硬脑膜内胶原纤维板层交替排列，具有明显的各向异性生物力学特性，且各向异性生物力学特性从头端至尾端逐渐明显。
