Absorptiometry and "osteoporosis": problems.

"Connecting the dots" between diverse clinical and other matters and an updated bone physiology reveals relationships that could modify some ideas about the roles and uses of absorptiometry in "osteoporosis" work. Herein, absorptiometry means that part of "clinical densitometry" that depends on X-ray absorption by bone and other tissues, thus excluding ultrasound methods and magnetic resonance imaging. The modifications concern, in part, some limitations of bone mineral "density" data, the kinds of physiological information that absorptiometry can and cannot provide, the relative importance of bone "mass" and whole-bone strength, how to define and study bone health and "osteoporosis," and two kinds of "osteoporotic fractures." As those modifications concern important national health care issues, they deserve answers based on hard evidence. Identifying those modifications might help others to evaluate them.