The Aging Skeleton

Direct, noninvasive measurements of the various skeletal components-axial and appendicular, trabecular and cortical-show that the greater frequency of fractures in women after the menopause or oophorectomy relates to skeletal fragility caused by rapid loss of vertebral spongiosa and the slower loss of peripheral cortex. Strangely, normal men lose vertebral spongiosa throughout adult life, often falling to values associated with fractures in women, but without known clinical manifestation. Bone loss and fractures of vertebrae, wrists, and hips in women are preventable by low-dose estrogen-gestagen replacement, or by certain progestins, but not by added calcium.