The Problem

Osteoporosis affects 54 million Americans and 325 million people worldwide. In women, the resulting low trauma fractures cause pain, disability and a higher rate of death than heart disease, stroke and breast cancer combined. The associated annual medical expenses will reach $25 billion in the US and €35 billion in Europe by 2025. Physicians use two methods to decide who to treat to prevent fractures.  One is to diagnose osteoporosis by measuring Bone Mineral Density (BMD) at sites of predominantly trabecular bone in the spine and hip. The other is to estimate fracture risk by assessing clinical risk factors. However, in prospective studies of post-menopausal women, most diagnosed with osteoporosis or high fracture risk, or both, did not fracture, and most fractures occurred in women diagnosed without osteoporosis or at low risk Measurement of cortical porosity has been proposed to improve decisions to treat, because after age 60, most bone loss is cortical and most fractures occur at predominantly cortical sites. Yet again, prospective research has found most patients with high cortical porosity did not fracture and most fractures occurred in patients with low cortical porosity. Missing from all these methods is a direct functional measure of cortical bone strength.