[The etiology of Perthes' disease and its relation to femur head dysplasia].

Due to the varying development of the vasculature of the proximal end of the femur, with a diminishing number of arteries ensuring blood supply and the subsequent reduction in the speed of flow in the myeloic sinuses, we describe here the origin of the latent ischemic phase of the proximal epiphysis of the femur, which constitutes the predisposition for the development of Perthes' disease. The hypoplasia of the arteries ensuring the blood supply of the proximal epiphysis of the femur may result in a latent ischemic phase which, under the influence of trigger factors, such as inflammations, traumas, etc., may lead to the evolution of Perthes' disease. The latent ischemic phase implies a phase of reduced resistance of the nucleus of ossification of the proximal epiphysis of the femur and corresponds to the "first infarct" in the findings of Inoue, Freeman and collaborators (1976). At the same time, it explains the findings of these and other authors in the sense that the "first infarct" affects the entire epiphyseal nucleus of the bone, a phenomenon which was not sufficiently explained by means of the theory of repeated infarcts. This publication is based on our own findings based on sections and animal experiments.