SIZE, SHAPE AND BONE MINERAL CONTENT OF THE HUMAN FEMUR IN GROWTH AND AGING (COMPUTED TOMOGRAPHY, PHOTON ABSORPTIOMETRY; ARIZONA).

Abstract

The mechanical behavior of any bone depends upon structural and material properties. Therefore, whole bone, cross-sectional geometric and bone mineral data need to be integrated in studies of bone growth and aging. This dissertation examines femoral growth and aging in the prehistoric Grasshopper Pueblo population of Arizona (A.D. 1275 to 1400). The techniques include osteometrics, computed tomography and photon absorptiometry. Human osteological collections obtained from archaeological sites are useful for studies of bone physiology and mechanics. Even though the subjects are no longer living, non-invasive techniques must often be used because the skeletal collections are data bases for many researchers. This apparently limiting attribute of the sample used in the present study forced the application of computed tomography for analysis of cross-sectional geometry. As the availability of computed tomography to research increases, it will become the method of choice because digital images are well-suited to automated analysis and CT can also provide density data. Variability related to side, age and sex is explored. Additionally, (1) structural properties increase much more than material properties in growth, (2) the morphology of the proximal femoral diaphysis depends more upon the angle of antetorsion than the cervicodiaphyseal angle, (3) there is evidence suggestive of structural compensation for loss of bone mineral in aging, (4) osteoporosis is found not to protect the femoral compartment of the knee joint from osteoarthrosis, (5) the onset of bone loss in females seems to have been early by modern standards, although the rates of loss were similar, and (6) differential bone loss within the femur due to the amount of bone present at maturity and not different rates of loss.