Letter to the Editor [Bone vol. 27/6 Dec 2000:875–876]

Why does a bone fracture? We should be able to answer that in a nontrivial manner, but we cannot. This is an embarrassing admission in an age when treatments are available that can reverse the tendency toward bone loss and thus lessen the danger of fracture. Furthermore, if we knew much more about the relation between the material bone and its fracture properties, we might be able to optimize treatments to improve the quality of the material, or at least predict when the chance of a fracture increases, taking into account also the state of the material. We have been working on aspects of this problem for 15 years. We were recently much humbled by some observations we made,2 which illustrate just how little is still known about the relations between bone microstructure and its mechanical properties. As these results are probably of interest to many in the bone community, and especially researchers focussing on osteoporosis, we thought it would be appropriate to briefly summarize the results and highlight major open questions. [First paragraph]