University of Oulu

Orava, H., Huang, L., Ojanen, S. P., Mäkelä, J. T. A., Finnilä, M. A. J., Saarakkala, S., Herzog, W., Korhonen, R. K., Töyräs, J., & Tanska, P. (2022). Changes in subchondral bone structure and mechanical properties do not substantially affect cartilage mechanical responses – A finite element study. Journal of the Mechanical Behavior of Biomedical Materials, 128, 105129.

Changes in subchondral bone structure and mechanical properties do not substantially affect cartilage mechanical responses : a finite element study

Saved in:
Author: Orava, Heta1,2; Huang, Lingwei1; Ojanen, Simo P.1,3;
Organizations: 1Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
2Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland
3Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
4Mechanical & Manufacturing Engineering, Schulich School of Engineering, University of Calgary, Calgary, Canada
5Science Service Center, Kuopio University Hospital, Kuopio, Finland
6School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Australia
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 15.7 MB)
Persistent link:
Language: English
Published: Elsevier, 2022
Publish Date: 2022-06-22


Subchondral bone structure has been observed to change in osteoarthritis (OA). However, it remains unclear how the early-stage OA changes affect the mechanics (stresses and strains) of the osteochondral unit. In this study, we aim to characterize the effect of subchondral bone structure and mechanical properties on the osteochondral unit mechanics. A 3-D finite element model of the osteochondral unit was constructed based on a rabbit femoral condyle μCT data and subjected to creep loading in indentation. Trabecular bone volume fraction, subchondral bone plate thickness, and equilibrium modulus were varied (including experimentally observed changes in early OA) to characterize the effect of these parameters on the osteochondral unit mechanics. At the end of the creep phase, the maximum principal strain at the bone surface of the cartilage-bone interface was decreased by 50% when the trabecular bone volume fraction was reduced from 48% to 28%. The maximum principal stress at the same location was decreased by 36% when plate thickness was reduced by 100 μm (−31%). In cartilage, small changes in the mechanics were seen near the cartilage-bone interface with a considerably thinner (−31%) plate. The changes in trabecular bone volume fraction, subchondral bone thickness and plate equilibrium modulus did not substantially affect the cartilage mechanics. Our results suggest that experimentally observed changes that occur in the subchondral bone structure in early OA have a minimal effect on cartilage mechanics under creep indentation loading; clear changes in the cartilage mechanics were seen only with an unrealistically soft subchondral bone plate.

see all

Series: Journal of the mechanical behavior of biomedical materials
ISSN: 1751-6161
ISSN-E: 1878-0180
ISSN-L: 1751-6161
Volume: 128
Article number: 105129
DOI: 10.1016/j.jmbbm.2022.105129
Type of Publication: A1 Journal article – refereed
Field of Science: 3126 Surgery, anesthesiology, intensive care, radiology
Funding: The research leading to these results has received funding from the Academy of Finland (#307932, #324529), Strategic funding of the University of Eastern Finland, Research Committee of the Kuopio University Hospital Catchment Area for the State Research Funding (#5041788), Finnish Cultural Foundation – Central Fund (#191044, #00180796), Kymenlaakso regional fund (#35201579) and North Savo regional fund (#65171624), Sigrid Juselius Foundation, Maire Lisko Foundation, Alfred Kordelin Foundation (#190317), Saastamoinen Foundation, Päivikki and Sakari Sohlberg Foundation and Emil Aaltonen Foundation. The funding sources had no role in the study design, collection, analysis and interpretation of data; in the writing of the manuscript; and in the decision to submit the manuscript for publication.
Copyright information: © 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (