Abstract

The mechanical properties of bones are governed by the same principles as those of man-made loadbearing structures, but the organism is able to adapt its bone structure to change in skeletal loading. In this overview of the determinants of the strength and stiffness of bone, a continuum approach has been taken, in which the behavior of a macroscopic structure depends on its shape and size, and on the mechanical properties of the material within. The latter are assumed to depend on the composition (porosity and mineralization) and organization (trabecular or cortical bone architecture, collagen fiber orientation, fatigue damange) of the bone. The effects of each these factors are reviewed. Als, the possible means of non-invasively estimating the strength or other mechanical properties of a bone are reviewed, including quantitative computed tomography, photon absorbtiometry, and ultrasonic measurements. The best estimates of strength have been obtained with photon absorptiometry and computed tomography, which at best are capable of accounting for 90 of the strength variability in a simple in vitro test, but results from different laboratories have been highly variable. Verf.-Referat