Quantifying Complex Micro‐Topography of Degenerated Articular Cartilage Surface by Contrast‐Enhanced Micro‐Computed Tomography and Parametric Analyses. Issue 4 (5th March 2019)

• Record Type: Journal Article
• Authors: Ylitalo, Tuomo; Finnilä, Mikko A.J.; Gahunia, Harpal K.; Karhula, Sakari S.; Suhonen, Heikki; Valkealahti, Maarit; Lehenkari, Petri; Hæggström, Edward; Pritzker, Kenneth P.H.; Saarakkala, Simo; Nieminen, Heikki J.
• Is Part Of: Journal of orthopaedic research. Volume 37:Issue 4(2019)
• Page Start: 855
• Page End: 866
• Publication Date: 2019-03-05
• Subjects: articular cartilage -- topography -- surface roughness -- 3D imaging -- microcomputed X‐ray tomography; Orthopedics -- Periodicals; Musculoskeletal system -- Periodicals; 616.7
• DOI: 10.1002/jor.24245
• Languages: English
• ISSNs: 0736-0266

Abstract

ABSTRACT: One of the earliest changes in osteoarthritis (OA) is a surface discontinuity of the articular cartilage (AC), and these surface changes become gradually more complex with OA progression. We recently developed a contrast enhanced micro‐computed tomography (μCT) method for visualizing AC surface in detail. The present study aims to introduce a μCT analysis technique to parameterize these complex AC surface features and to demonstrate the feasibility of using these parameters to quantify degenerated AC surface. Osteochondral plugs ( n = 35) extracted from 19 patients undergoing joint surgery were stained with phosphotungstic acid and imaged using μCT. The surface micro‐topography of AC was analyzed with developed method. Standard root mean square roughness (Rq ) was calculated as a reference, and the Area Under Curve (AUC) for receiver operating characteristic analysis was used to compare the acquired quantitative parameters with semi‐quantitative visual grading of μCT image stacks. The parameters quantifying the complex micro‐topography of AC surface exhibited good sensitivity and specificity in identifying surface continuity (AUC: 0.93, [0.80 0.99]), fissures (AUC: 0.94, [0.83 0.99]) and fibrillation (AUC: 0.98, [0.88 1.0]). Standard Rq was significantly smaller compared with the complex roughness (CRq ) already with mild surface changes with all surface reference parameters − continuity, fibrillation, and fissure sum. Furthermore, only CRq showed a significant difference when comparing the intact surface with lowest fissure sum score. These results indicate that the presented method for evaluating complex AC surfaces exhibit potential to identify early OA changes in superficial AC and is dynamic throughout OA progression. © 2019 The Authors. Journal of Orthopaedic Research ® Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. Society. 9999:1–12, 2019. Abstract : Surface topology is a key feature in a histopathological grading of osteoarthritis. These features can be extremely complex and standard roughness analysis cannot be used to quantify these changes. To overcome this issue novel semi‐automatic analysis software was developed. The sensitivity and specificity of established parameters was evaluated by using developed software to analyze 40 osteochondral samples imaged with a contrast enhanced micro‐computed tomography. Established parameters exhibited high sensitivity and specificity when used to detect early micro‐topographical changes in AC.