Age and Sex Related Changes in the Amount of Cortex of Normal Human Ribs

The group of diseases designated by the term "the osteoporoses" is becoming increasingly important as the average age of our population rises.Present methods of treating these diseases leavc much to be desired, since it is only rarely possible to demonstrate an increase in bone mass even after years of faithful adherence to one of the commonly used therapeutic regimes.As Sedlin noted (1964 a, 1964 b ) , this failure of treatment has suggested to many that our present concepts of the physiologic mechanisms causing osteoporosis may henefit from reexamination.In this respect it is axiomatic that it is difficult to understand diseased tissues unless one has a good knowledge of the normal.These facts have stimulated a number of investigators to perform longitudinal studies (with respect to age) of normal bone, hoping thereby to learn how to define what the normal is and to provide a rational basis for comparing abnormal skeletal tissue with normal.These studies include the ash and volumetric studies of Trotter, Broman & Peterson (1960) and of Merz, Trotter & I Peterson (1956), the physical densities of W r a y , Siigarman & Schneider ( 19631, the roentgen densities of Linduhl & Lindgren (1962), the highly accurate densities of Arnold (1960); and the osteoid seam counts of Jee et al. (1964).Almost all authors who have worked on these problems have 1 Work supportcd by grants AM-04186