Poromechanical Modeling of Porcine Knee Joint Using Indentation Map of Articular Cartilage

Site- and Zone-Dependent Changes in Proteoglycan Content and Biomechanical Properties of Bluntly and Sharply Grooved Equine Articular Cartilage

“…Fourth, while indentation was not necessarily conducted perfectly perpendicular to the cartilage surface, stresses and strains normal to the surface were calculated and used in the analyses. 57 This caused minor variations in the final strains between the samples and measured locations. Yet, we were in the linear region of the equilibrium stress-strain curves, thus, this uncertainty should have negligible effect on the results.…”

“…Then, indentation occurred in the vertical ( z ) direction, and by using the surface angle, the vertical force and displacement were converted to the component normal to the surface at the measurement point by the software. 57 …”

“…Then, indentation occurred in the vertical (z) direction, and by using the surface angle, the vertical force and displacement were converted to the component normal to the surface at the measurement point by the software. 57 A one-step stress-relaxation test perpendicular to the surface was applied to each point with 15% of the strain of cartilage thickness (amplitude) and a strain rate of 100%/s, followed by 300 s of relaxation. 9,31,33 The required time to reach equilibrium (relaxation rate at the end of the measurement < 0.1 Pa/min) was selected based on pilot tests.…”