This Thesis is about generalised osteoporosis, a condition in which there is reduction of calcified bone mass per unit volume of bone without distinctive biochemical changes in the serum. The incidence, aetiology, and pathology of senile osteoporosis, the most common variety of generalised osteoporosis, is studied. The Introduction defines generalised osteoporosis and describes the conditions in which it may occur, thus providing the background of knowledge for this study. Because the hormones produced by the adrenal glands, ovaries and testes are obviously implicated in the production of osteoporosis the relevant articles describing the effects of cortisone, oestrogens, and androgens on bone are reviewed and summarised. The problems involved in radiological evaluation of the degree of bone mineralisation and previously reported methods are also briefly described. The work is divided into three parts. Part I describes a simple but accurate radiographic method of estimating the degree of mineralisation of lumbar vertebral bone slabs. This method is correlated with chemical analysis of the calcium content of the vertebral slabs and bone histological examinations, undertaken with a view to determining the range of variation of calcium content and radiographic density of normal and osteoporotic bone. A series of 300 necropsy cases was examined in this manner. Part II is a study of the histological and histochemical patterns of adrenal glands obtained within six hours of death from 31 of these 300 cases. By reference to the vertebral bone density results the adrenal cortical histochemical patterns in osteoporotic cases are compared with those in cases having a high normal bone density. Part III describes how osteoporosis was produced in male albino rats (150 g.) by ablation of adrenal glands and testes and daily cortisone injections. The osteoporosis was treated either by oily solutions or microcrystalline suspensions of the sex hormones in various combinations and the results were assessed by radiographic, chemical, and histological examinations of the long bones. The General Discussion which follows deals with the additional points raised by the combination of these three studies as a result of which a clear cut picture of the condition called senile osteoporosis is presented. The text and tables are presented in Volume I and the illustrations in Volume II. An Appendix including some of the technical methods and an account of the work personally performed is also presented in Volume I
