University of Oulu

Ebrahimi, M., Finnilä, M.A.J., Turkiewicz, A. et al. Elastic, Dynamic Viscoelastic and Model-Derived Fibril-Reinforced Poroelastic Mechanical Properties of Normal and Osteoarthritic Human Femoral Condyle Cartilage. Ann Biomed Eng 49, 2622–2634 (2021).

Elastic, dynamic viscoelastic and model-derived fibril-reinforced poroelastic mechanical properties of normal and osteoarthritic human femoral condyle cartilage

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Author: Ebrahimi, Mohammadhossein1,2; Finnilä, Mikko A. J.2; Turkiewicz, Aleksandra3;
Organizations: 1Department of Applied Physics, University of Eastern Finland, POB 1627, 70211, Kuopio, Finland
2Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
3Clinical Epidemiology Unit, Department of Clinical Sciences Lund, Orthopaedics, Faculty of Medicine, Lund University, Lund, Sweden
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 2 MB)
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Language: English
Published: Springer Nature, 2021
Publish Date: 2021-11-09


Osteoarthritis (OA) degrades articular cartilage and weakens its function. Modern fibril-reinforced poroelastic (FRPE) computational models can distinguish the mechanical properties of main cartilage constituents, namely collagen, proteoglycans, and fluid, thus, they can precisely characterize the complex mechanical behavior of the tissue. However, these properties are not known for human femoral condyle cartilage. Therefore, we aimed to characterize them from human subjects undergoing knee replacement and from deceased donors without known OA. Multi-step stress-relaxation measurements coupled with sample-specific finite element analyses were conducted to obtain the FRPE material properties. Samples were graded using OARSI scoring to determine the severity of histopathological cartilage degradation. The results suggest that alterations in the FRPE properties are not evident in the moderate stages of cartilage degradation (OARSI 2-3) as compared with normal tissue (OARSI 0-1). Drastic deterioration of the FRPE properties was observed in severely degraded cartilage (OARSI 4). We also found that the FRPE properties of femoral condyle cartilage related to the collagen network (initial fibril-network modulus) and proteoglycan matrix (non-fibrillar matrix modulus) were greater compared to tibial and patellar cartilage in OA. These findings may inform cartilage tissue-engineering efforts and help to improve the accuracy of cartilage representations in computational knee joint models.

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Series: Annals of biomedical engineering
ISSN: 0090-6964
ISSN-E: 1573-9686
ISSN-L: 0090-6964
Volume: 49
Issue: 9
Pages: 2622 - 2634
DOI: 10.1007/s10439-021-02838-4
Type of Publication: A1 Journal article – refereed
Field of Science: 217 Medical engineering
Funding: Open access funding provided by University of Eastern Finland (UEF) including Kuopio University Hospital.
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