Transient stiffening of cartilage during joint articulation: A microindentation study. (January 2021)

• Record Type: Journal Article
• Authors: Yuh, Catherine; Laurent, Michel P.; Espinosa-Marzal, Rosa M.; Chubinskaya, Susan; Wimmer, Markus A.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 113(2021)
• Publication Date: 2021-01
• Subjects: Cartilage -- Articular loading -- Tribology -- Microindentation -- Superficial zone; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2020.104113
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: As a mechanoactive tissue, articular cartilage undergoes compression and shear on a daily basis. With the advent of high resolution and sensitive mechanical testing methods, such as micro- and nanoindentation, it has become possible to assess changes in small-scale mechanical properties due to compression and shear of the tissue. However, investigations on the changes of these properties before and after joint articulation have been limited. To simulate articular loading of cartilage in the context of human gait, a previously developed bioreactor system was used. Immediately after bioreactor testing, the stiffness was measured using microindentation. Specifically, we investigated whether the mechanical response of the tissue was transient or permanent, dependent on counterface material, and an effect limited to the superficial zone of cartilage. We found that cartilage surface stiffness increases immediately after articular loading and returns to baseline values within 3 hr. Cartilage-on-cartilage stiffening was found to be higher compared to both alumina- and cobalt chromium-on-cartilage stiffening, which were not significantly different from each other. This stiffening response was found to be unique to the superficial zone, as articular loading on cartilage with the superficial zone removed showed no changes in stiffness. The findings of this study suggest that the cartilage superficial zone may adapt its stiffness as a response to articular loading. As the superficial zone is often compromised during the course of osteoarthritic disease, this finding is of clinical relevance, suggesting that the load-bearing function deteriorates over time. Graphical abstract: Image 1 Highlights: A bioreactor-indenter workflow to assess cartilage stiffness changes from articular loading. Articular loading on cartilage led to a transient increase in surface stiffness. A cartilage counterface led to more stiffening than cobalt chromium and alumina. Removal of the superficial zone led to a loss of the transient stiffening response.