VA Research and Development LOGO

Logo for the Journal of Rehab R&D
Vol. 37 No. 2, March/April 2000
Pages 145 - 152

Mechanobiology in the development, maintenance, and degeneration of articular cartilage

Gary S. Beaupré, PhD; Sheila S. Stevens, PhD; Dennis R. Carter, PhD

Rehabilitation Research and Development Center, VA Palo Alto Health Care System, Palo Alto, CA 94304; Biomechanical Engineering Division, Mechanical Engineering Department, Stanford University, Stanford, CA 94305; Kyphon Inc., 3110 Coronado Drive, Santa Clara, CA 95054

Abstract — During skeletal development, the establishment of a layer of cartilage at the ends of long bones is intimately linked to the process of endochondral ossification. Previous in vivo studies and computer models suggest that mechanobiological factors can play a key role in modulating cartilage growth and ossification. Specifically, intermittent hydrostatic pressure is thought to maintain cartilage, and shear stresses encourage cartilage destruction and ossification. In the present investigation we examined the combined effects of hydrostatic pressure and shear stress--in the form of an osteogenic index--on the development of a layer of articular cartilage, using an idealized finite element computer model. The results of our analyses provide further support for the view that mechanobiological factors play a key role in regulating the distribution of cartilage thickness and in maintaining a stable cartilage layer at maturity. The model predicts that joints that experience higher contact pressures will have thicker cartilage layers. These predictions are consistent with observations of cartilage thickness in both humans and animals. Variations in articular mechanical load are predicted to modulate cartilage thickness. These results are consistent with the view that the mechanobiological factors responsible for the development of diarthrodial joints eventually lead to cartilage degeneration and osteoarthritis (OA) with aging.

Key words: cartilage thinning, computer modeling, endochondral ossification, hydrostatic stress, mechanobiology, osteoarthritis (OA), shear stress.

View HTML   ¦    View PDF   ¦    Contents Vol. 37, No. 2