A poroelastic finite element model of a heterogeneous articular cartilage disc was
created to examine the tissue response to low amplitude (± 2% strain), low
frequency (0.1 Hz) dynamic unconfined compression (UCC). A strong correlation
has been made between the relative fluid velocity and stimulation of
glycosaminoglycan synthesis. A contour plot of the model shows the relative fluid
velocity during compression exceeds a trigger value of 0.25 μm/s at the radial
periphery. Dynamic UCC biochemical results have also reported a higher
glycosaminoglycan content in this region versus that of day 0 specimens. Fluid
velocity was also found not to be the dominant physical mechanism that
stimulates collagen synthesis; the heterogeneity of the fluid velocity contour plot
conflicts with the homogeneous collagen content from the biochemical results. It
was also found that a Tresca (shear) stress trigger of 0.07 MPa could provide
minor stimulation of glycosaminoglycan synthesis. A feasibility study on
modeling a heterogeneous disc was conducted and found convergence issues with
the jump in properties from the superficial to middle layers of the disc. It is
believed that the superficial layer contains material properties that allow the tissue
to absorb much of the compressive strain, which in turn increases pressure and
causes convergence issues in ABAQUS. The findings in this thesis may help
guide the development of a growth and remodeling routine for articular cartilage.
| Identifer | oai:union.ndltd.org:CALPOLY/oai:digitalcommons.calpoly.edu:theses-1575 |
| Date | 01 June 2011 |
| Creators | Kam, Kelsey Kiyo |
| Publisher | DigitalCommons@CalPoly |
| Source Sets | California Polytechnic State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Master's Theses |
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