Alterations in the Mechanical Properties of the Human Chondrocyte Pericellular Matrix With Osteoarthritis

[+] Author and Article Information
Leonidas G. Alexopoulos

Department of Surgery, Duke University Medical Center, Durham, NC 27710, and Department of Biomedical Engineering, Duke University, Durham, NC 27708

Mansoor A. Haider

Department of Mathematics, North Carolina State University, Raleigh, NC 27695

Thomas P. Vail

Department of Surgery, Duke University Medical Center, Durham, NC 27710

Farshid Guilak

Department of Surgery, Duke University Medical Center, Durham, NC 27710, Department of Biomedical Engineering, Duke University, Durham, NC 27708

J Biomech Eng 125(3), 323-333 (Jun 10, 2003) (11 pages) doi:10.1115/1.1579047 History: Received August 13, 2002; Revised January 22, 2003; Online June 10, 2003
Copyright © 2003 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
The chondron isolation technique—microaspirator: The device consists of a 30 ml syringe with a trimmed 22-gauge needle. The plunger was secured in the upright position, and a constant suction pressure from a vacuum line (∼50 kPa) was applied to the syringe. The cartilage slice was immersed in medium. After ∼3 minutes of application of suction pressure to the top or bottom side of the slice, the aspirated media was centrifuged and the bottom 2 ml was collected.
Grahic Jump Location
(a) Micropipette aspiration of the chondron; (b) schematic representation of the elastic layered half-space model. The layer corresponds to the PCM and the substrate to the chondrocyte. Under the action of the suction pressure Δp, the layer is drawn into the micropipette forming a projection length L (aspiration length).
Grahic Jump Location
Validation of the layered model: (a) Displacement profiles using the layered model reduced to an incompressible elastic half-space model. The y-axis is the dimensionless projection of the layer surface inside the micropipette. The pipette wall extends from r/ri=1 to r/ri=1.5. (b) Displacement profiles for the incompressible elastic half-space model developed by Theret et al. 49 (adapted with permission). The two plots are in excellent agreement.
Grahic Jump Location
Effect of the layer thickness h* and the Young’s moduli ratio Elayer/Esubstrate in the calculation of the constant C* for the Young’s modulus of the layer (Eq. (33)) assuming incompressibility (ν12=0.5) and r0*=1.5. If Elayer/Esubstrate=1 or h*→∞, we obtain the half-space solution (C*=0.98). If Elayer/Esubstrate→∞, the model reduces to the aspiration of a shell.
Grahic Jump Location
Effect of the Poisson’s ratio of the layer (ν1) in the calculation of the constant C* (Eq. (33)). For simplicity, the results of the shell case are presented (Elayer/Esubstrate→∞).
Grahic Jump Location
Young’s moduli of the PCM calculated using the layered model. Significant difference of the Young’s moduli of PCM were observed between non-OA and OA chondrons for both the surface and middle/deep zones (*p<0.05,**p<0.001 versus the non-OA counterpart). No significant differences were observed between surface and middle/deep zone.
Grahic Jump Location
Young’s modulus of the PCM determined using the half-space model (white bar), the layered model (gray bar), and the shell model (black bar). Significant differences were found between non-OA and OA chondrons using either model (*p<0.001 versus the non-OA controls). The data is pooled for surface and middle/deep zones. For the non-OA chondrons, the half-space model predicts ∼38% lower Young’s modulus than the other two models; for OA chondrons this difference is ∼20% (**p<0.001 versus layered model or shell model). The shell and layered model predict almost the same Young’s modulus.




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In