Fractal dimension: A complementary diagnostic indicator of osteoporosis to bone mineral density.

Morbidity of osteoporosis is increasing as the world population grows and ages, but bone mineral density (BMD) as a common-used diagnostic indicator is not omnipotent in predicting the bone fragility. According to the definition of osteoporosis by World Health Organization (WHO), the present hypothesis proposes an additional fractal-dimension indicator less than 3 to measure the structural change of bones, and further to diagnose osteoporotic patients with complications, to which BMD is insensitive. Literature reports support that the fractal dimension is more sensitive than BMD in specific cases. The hypothesis shows a promise not only in improving the accuracy of screening osteoporotic patients as a complementary indicator to BMD, but also in evaluating mechanical properties of osteoporotic bone and bone-repair effect of bone tissue engineering.