Sex and ethnic differences in bone architecture.

Technologic developments and applications such as dual energy x-ray absorptiometry, magnetic resonance imaging, and computed tomography have enabled researchers to assess bone quantity (ie, bone mineral density) and bone quality (ie, bone architecture), which are two important and independent contributions to bone strength. Recent studies on sex differences in bone architecture indicate that a number of biomechanical variables lead to increased bone strength in males compared with females. Ethnic differences in bone architecture are less clear-cut, indicating a need to identify and test the social and biologic variables that race and ethnicity represent. New methods using magnetic resonance imaging technology may become important in creating efficient and reliable in vivo methods of assessing features of bone architecture that are relevant to fracture risk and contribute to the elucidation of sex and ethnic differences in osteoporosis.