The Role of Mechanics in Osteoarthritis: Modeling the Cellular Microenvironment in Articular Cartilage

Mansoor Haider
Mathematics & Biomathematics Graduate Program, North Carolina State University

(October 23, 2006 10:30 AM - 11:30 AM)

The Role of Mechanics in Osteoarthritis: Modeling the Cellular Microenvironment in Articular Cartilage

Abstract

Articular cartilage is the primary load-bearing soft tissue in joints such as the knee, shoulder and hip. This tissue can be idealized as a continuum mixture of interstitial water and a solid extracellular matrix comprised of collagen fibers and negatively charged proteoglycan macromolecules. Degradation of cartilage extracellular matrix leads to osteoarthritis, a painful condition that is predominantly associated with aging. The extracellular matrix is maintained by a sparse population of cells (chondrocytes) that are encapsulated by a thin, stiff layer called the pericellular matrix. Since mature cartilage is avascular and aneural, mechanical variables in the vicinity of the chondrocytes strongly influence cell metabolic activity and, ultimately, the health of the tissue. In this talk, I will present an overview of biphasic (solid-fluid) and triphasic (solid-fluid-ion) continuum mixture models of mechanical and chemical loading in articular cartilage. Analytical and numerical solutions of the associated interface problems will be presented. Results will be discussed in the context of assessing the impact of pericellular matrix properties, and alterations with osteoarthritis, on the cellular microenvironment in cartilage.