Three-dimensional microstructure of human meniscus posterior horn in health and osteoarthritis

I Kestilä,E Folkesson,M.A Finnilä,A Turkiewicz,P Önnerfjord,V Hughes,J Tjörnstrand,M Englund,S Saarakkala

doi:10.1016/j.joca.2019.07.003

I Kestilä, E Folkesson + Show 7 more

Open Access

https://doi.org/10.1016/j.joca.2019.07.003

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Abstract

To develop and perform exvivo 3D imaging of meniscus posterior horn microstructure using micro-computed tomography (μCT), and to compare specimens from healthy references against end-stage osteoarthritis (OA) using conventional section-based histology and qualitative μCT. We retrieved human medial and lateral menisci from 10 deceased donors without knee OA (healthy references) and medial and lateral menisci from 10 patients having total knee replacement for medial compartment OA. Meniscal posterior horns were dissected and fixed in formalin. One subsection underwent hexamethyldisilazane (HMDS) treatment and μCT imaging. Pauli's histopathological scoring was performed for 3 other subsections. The differences in histopathological scores were estimated using mixed linear regression, resulting in fixed effects estimates for within-knee comparisons and adjusted for age and body mass index for between-subjects comparisons. 3D visualization with μCT qualitatively revealed similar microstructural changes in the posterior horns as conventional histology. The mean histopathological score was higher for medial menisci from OA knees vs both medial reference menisci (mean difference [95% CI], 3.9 [2.6,5.3]), and lateral menisci from OA knees (3.9 [2.9,5.0]). The scores were similar between lateral menisci from OA knees and lateral reference menisci (0.8 [-0.6,2.2]), and between medial and lateral reference menisci (0.8 [-0.3,1.9]). HMDS-based μCT protocol allows unique 3D visualization of meniscus microstructures. Posterior horns of medial menisci from medial compartment OA knees had higher histopathological scores than both the lateral posterior horns from the same OA knees and medial reference menisci, suggesting a strong association between meniscus degradation and unicompartmental knee OA.

Highlights

Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, The menisci are crescent-shaped fibrocartilaginous wedges located in the medial and lateral compartments of the knee joint
From in vivo magnetic resonance imaging (MRI) of human knees, it appears that the degeneration is most commonly found in the posterior horn of the medial meniscus[11], making this zone of particular interest to further studies
Using the HDMS-based micro-computed tomography (mCT) technique and the histopathological analyses, we found that degeneration of the meniscus posterior horn in Section 1 Section 2 Section 3

Summary

Introduction

Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, The menisci are crescent-shaped fibrocartilaginous wedges located in the medial and lateral compartments of the knee joint. It has been suggested that such degenerative lesions may begin as proteolytic degradation of the meniscus, leading to a decrease in its tensile strength[8]. This in turn may result in a degenerative meniscal tear due to the inability of the weakened meniscus to resist normal loads and shear stress in the knee joint[8]. From in vivo magnetic resonance imaging (MRI) of human knees, it appears that the degeneration is most commonly found in the posterior horn of the medial meniscus[11], making this zone of particular interest to further studies

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