Growth, adaptation and aging of the skeletal system

Our skeletal system requires a certain amount of maintenance in order to withstand the external loading appropriately for a long period. This maintenance is performed by specialized cells; i.e., osteoclasts and osteoblasts, which continuously resorb and rebuild the bony matrix in small packages. It is presently not known how these cells are being signalled such that they undertake appropriate actions and resorb damaged (weak) bone and replace it with a new. It is well recognized that mechanical loading has an important effect on the cellular events. Mechanical load distribution in bony structures can be calculated using the finite element method. In addition, the effects on growth, adaptation and degeneration due to this loading can be incorporated into these models as well. That gives the opportunity to study the interaction between biological and mechanical aspects in bone tissue. In this study a few examples of such an interaction are simulated numerically and their biological or clinical consequences are discussed.