[Twelve theses on the pathogenesis of primary and secondary osteoporosis based on histological observations].

In spite of a well defined clinical syndrome and a wealth of biochemical information, the pathogenesis of primary osteoporosis is still uncertain. Microscopic evaluation of semithin sections of 1727 bone biopsies from patients suffering from "idiopathic" osteoporosis and 288 from patients with secondary osteoporosis has lead to the recognition of a pathogenetic relationship between changes of the bone marrow capillaries and atrophy of the trabecular bone in these groups. A new hypothesis is proposed for the structural and functional role of the bone marrow capillaries in normal and abnormal osseous remodelling; this is based on comparative morphometric analysis of normal cases and of hypo- and hyperplastic changes of the myelogenous and osseous tissues in various haematological and bone disorders. The hormonal and nervous regulation of the microcirculation of bone marrow may offer a new approach to the understanding and cure of so-called idiopathic osteoporosis.