The relationship between elastic fibre disorders and disc degeneration, aging and progression of spine deformity have been discussed in a small number of studies. However, the clinical relevance of elastic fibres in the annulus fibrosus (AF) of the disc is poorly understood. Ultrastructural visualization of elastic fibres is an important step towards understanding their structure-function relationship. In our previous studies, a novel technique for visualization of elastic fibres across the AF was presented and their ultrastructural organization in intra- and inter-lamellar regions was compared. Using the same novel technique in the present study, the ultrastructural organization of elastic fibres in the partition boundaries (PBs), which are located between adjacent collagen bundles, is presented for the first time. Visualization of elastic fibres in the PBs in control and partially digested (digested) samples was compared, and their orientation in two different cutting planes (transverse and oblique) were discussed. The ultrastructural analysis revealed that elastic fibres in PBs were a well-organized dense and complex network having different size and shape. Adjacent collagen bundles in a cross section (CS) lamella appear to be connected to each other, where elastic fibres in the PBs were merged in parallel or penetrated into the collagen bundles. There was no significant difference in directional coherency coefficient of elastic fibres between the two different cutting planes (p = 0.35). The present study revealed that a continous network of elastic fibres may provide disc integrity by connecting adjacent bundles of CS lamellae together. Compared to our previous studies, the density of the elastic fibre network in PBs was lower, and fibre orientation was similar to the intra-lamellar space and inter-lamellar matrix.

Statement of significance

A detailed ultrastructural study in the partition boundaries of the annulus fibrouses within the disc revealed a well-organized elastic fibre network with a complex ultrastructure. The continous network of elastic fibres may provide disc integrity by connecting adjacent bundles of cross section lamellae together. The density of the elastic fibre network in PBs was lower, and fibre orientation was similar to the intra-lamellar space and the inter-lamellar matrix.

少数研究已讨论了弹性纤维疾病与椎间盘退变，衰老和脊柱畸形进展之间的关系。但是，人们对椎间盘纤维环（AF）中弹性纤维的临床相关性了解甚少。弹性纤维的超微结构可视化是了解其结构与功能关系的重要一步。在我们以前的研究中，提出了一种新颖的可视化AF内弹性纤维的技术，并比较了它们在层内和层间区域的超微结构。在本研究中使用相同的新技术，首次提出了位于相邻胶原束之间的分区边界（PBs）中弹性纤维的超微结构。比较了对照和部分消化（消化）样品中PB中的弹性纤维的可视化，并讨论了它们在两个不同切割平面（横向和倾斜）中的方向。超微结构分析表明，PB中的弹性纤维是组织良好的致密且复杂的网络，具有不同的大小和形状。横截面（CS）薄片中的相邻胶原束似乎相互连接，其中PB中的弹性纤维平行合并或渗透到胶原束中。在两个不同的切割平面之间，弹性纤维的方向相干系数没有显着差异（p = 0.35）。本研究表明，连续的弹性纤维网络可以通过将相邻的CS薄片束连接在一起来提供椎间盘的完整性。

重要声明

在椎间盘内纤维环的分隔边界上进行的详细的超微结构研究表明，组织良好的弹性纤维网络具有复杂的超微结构。弹性纤维的连续网络可以通过将相邻的横截面薄片束连接在一起而提供盘的完整性。PB中的弹性纤维网络密度较低，且纤维取向类似于层内空间和层间基质。