In vitro method for 3D morphometry of human articular cartilage chondrons based on micro-computed tomography. Issue 8 (August 2018)

• Record Type: Journal Article
• Authors: Kestilä, I.; Thevenot, J.; Finnilä, M.A.; Karhula, S.S.; Hadjab, I.; Kauppinen, S.; Garon, M.; Quenneville, E.; Haapea, M.; Rieppo, L.; Pritzker, K.P.; Buschmann, M.D.; Nieminen, H.J.; Saarakkala, S.
• Is Part Of: Osteoarthritis and cartilage. Volume 26:Issue 8(2018)
• Page Start: 1118
• Page End: 1126
• Publication Date: 2018-08
• Subjects: Hexamethyldisilazane -- Osteoarthritis -- Segmentation -- Morphology -- 3D analysis; Osteoarthritis -- Periodicals; Cartilage -- Periodicals; Osteoarthritis -- Periodicals; Cartilage -- Periodicals; Arthrose -- Périodiques; Articulations -- Maladies -- Périodiques; 616.7223005
• DOI: 10.1016/j.joca.2018.05.012
• Languages: English
• ISSNs: 1063-4584

Abstract

Summary: Objective: The aims of this study were: to 1) develop a novel sample processing protocol to visualize human articular cartilage (AC) chondrons using micro-computed tomography (μCT), 2) develop and validate an algorithm to quantify the chondron morphology in 3D, and 3) compare the differences in chondron morphology between intact and osteoarthritic AC. Method: The developed protocol is based on the dehydration of samples with hexamethyldisilazane (HMDS), followed by imaging with a desktop μCT. Chondron density and depth, as well as volume and sphericity, were calculated in 3D with a custom-made and validated algorithm employing semi-automatic chondron selection and segmentation. The quantitative parameters were analyzed at three AC depth zones (zone 1: 0–10%; zone 2: 10–40%; zone 3: 40–100%) and grouped by the OARSI histological grades (OARSI grades 0–1.0, n = 6; OARSI grades 3.0–3.5, n = 6). Results: After semi-automatic chondron selection and segmentation, 1510 chondrons were approved for 3D morphometric analyses. The chondrons especially in the deeper tissue (zones 2 and 3) were significantly larger ( P < 0.001) and less spherical ( P < 0.001), respectively, in the OARSI grade 3–3.5 group compared to the OARSI grade 0–1.0 group. No statistically significant difference in chondron density between the OARSI grade groups was observed at different depths. Conclusion: We have developed a novel sample processing protocol for chondron imaging in 3D, as well as a high-throughput algorithm to semi-automatically quantify chondron/chondrocyte 3D morphology in AC. Our results also suggest that 3D chondron morphology is affected by the progression of osteoarthritis (OA).