Viscoelasticity of articular cartilage: Analysing the effect of induced stress and the restraint of bone in a dynamic environment. (November 2017)

• Record Type: Journal Article
• Authors: Lawless, Bernard M.; Sadeghi, Hamid; Temple, Duncan K.; Dhaliwal, Hemeth; Espino, Daniel M.; Hukins, David W.L.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 75(2017)
• Page Start: 293
• Page End: 301
• Publication Date: 2017-11
• Subjects: Articular cartilage -- Frequency -- Loss -- Modulus -- Storage -- Viscoelasticity; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2017.07.040
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: The aim of this study was to determine the effect of the induced stress and restraint provided by the underlying bone on the frequency-dependent storage and loss stiffness (for bone restraint) or modulus (for induced stress) of articular cartilage, which characterise its viscoelasticity. Dynamic mechanical analysis has been used to determine the frequency-dependent viscoelastic properties of bovine femoral and humeral head articular cartilage. A sinusoidal load was applied to the specimens and out-of-phase displacement response was measured to determine the phase angle, the storage and loss stiffness or modulus. As induced stress increased, the storage modulus significantly increased ( p < 0.05). The phase angle decreased significantly ( p < 0.05) as the induced stress increased; reducing from 13.1° to 3.5°. The median storage stiffness ranged from 548 N/mm to 707 N/mm for cartilage tested on-bone and 544 N/mm to 732 N/mm for cartilage tested off-bone. On-bone articular cartilage loss stiffness was frequency independent ( p > 0.05); however, off-bone, articular cartilage loss stiffness demonstrated a logarithmic frequency-dependency ( p < 0.05). In conclusion, the frequency-dependent trends of storage and loss moduli of articular cartilage are dependent on the induced stress, while the restraint provided by the underlying bone removes the frequency-dependency of the loss stiffness.