Micromorphological Investigations of Intervertebral Disk Degeneration using Electron Microscopy

Abstract

Introduction Intervertebral disk (ID) degeneration can be distinguished by various changes in the tissue structure like delamination and crack formation of the collagenous matrix as well as cellular changes like cell aging and variances in the amount and allocation of the cells. These indications of ID degeneration are shifting while increasing grade of degeneration. It has been confirmed that the ultrafine structure of disk tissue significantly influence the disk stability. Conventional clinical imaging techniques like CT and MRI are not able to visualize tissue morphology and tissue damages on this structure level. Materials and Methods To get detailed information about the degeneration and to achieve deeper insights into the morphology and microstructure of disk tissue, samples are investigated by scanning electron microscopic (SEM) techniques with corresponding sample preparations. The method allows the determination of the tissue morphology at high resolution. During this study, sequester material, achieved by standard sequestrectomy of 48 patients of different grades of degeneration, has been investigated. Results In the extracted tissue, we visualize different regions with characteristic microstructural damage behaviors, such as regions of prevalent micro cracks, or regions of fiber matrix delamination or fiber bridging. Furthermore, variations in cell density and cell morphology conditioned by the grade of degradation have been analyzed. Identified microstructural characteristics are correlated with MRI-based clinical rating scale for degeneration. Conclusion Investigations of degeneration characteristics of ID tissues by SEM propose high resolved analysis of both the tissue structure and the cell morphology. Correlation of the gleaned data regarding studies and classifications like Thompson scale shows a diffuse incidence of degeneration characteristic. The estimation of the grade of ID tissue degeneration, only by date achieved from MRI, is insufficient to appoint tissue-specific grade of degeneration. It is necessary to develop a new rating system considering variances within the tissue macro- and micromorphology as well as MRI data. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared