CAUSE OF PERTHES ’ DISEASE 333 A THEORY AS TO THE CAUSE OF PERTHES ’ DISEASE BASED ON ROENTGENOLOGIC FINDINGS

The symptoms, clinical course, pathology, and treatment of the disease entity variously known as Legg’s disease, Legg-Calv#{233} disease, Perthes ’ disease, coxa plana, pseudocoxalgia, osteochondritis deformans juvenilis, etc., are now fairly well understood, but the cause remains an illusive and fascinating problem. The etiologic speculations and theories have practically narrowed down to three: (1) the infective theory; (2) the traumatic theory; and (3 and 4) the congenital theory. The trouble is that no one of these theo-ries seems to explain all cases. The nature of the disease in question is such that it has to be studied mainly by X-ray examination and clinical observation rather than histologically or by experiment; consequently conclusions as to cause must be arrived at speculatively or theoretically. If a theory as to cause has to be accepted, however, it should at least be one that will cover all cases. The following thirteen cases are presented for study and discussio