The interrelationships between bone mineral at different skeletal sites in male and female cadavera.

When assessing the mineral content of the skeleton investigators customarily make either radiographic or photon absorption measurements at one particular site on the assumption that the site selected is representative of the remainder of the skeleton. Unfortunately few of the established techniques for bone mineral quantification actually provide information on the relationship between the particular site selected and other parts of the skeleton. Measurements of skeletal mass in vito by either morphological or densitometric techniques are strictly limited to those sites which are readily accessible, where the bony contour is most uniform and where large individual variations in soft-tissue coverage do not occur (Jackson 1951). It is for these reasons that the shafts ofcertain long bones have been used most frequently for the quantitative measurement of bone mineral in vivo (Henny 1950; Barnett and Nordin 1960; Doyle 1961; Meema 1963; Meema, Harris and Porrett 1964; Anderson, Shimmins and Smith 1966). The shaft sites that have been employed, however, are composed almost entirely ofcortical compact bone where fractures seldom occur. Many authorities consider that loss of trabecular bone is the dominant feature of osteoporosis, and therefore it is important to know just how representative of trabecular bone are measurements at sites where cortical bone predominates. Furthermore, fractures of the distal radius, the femoral neck and the vertebral bodies commonly occur in osteoporotic subjects, but these sites, which are largely composed of trabecular bone, are not readily amenable to reproducible measurements of density in vito. It was considered desirable therefore to examine the relationship between the mineral