Under this head, an affection of the hip joint has been described which is characterized, anatomically, by a deepening of the acetabular cavity, due to a displacement, medially, of its inner wall, and, clinically, by pain and limitation of abduction and sometimes of adduction and of rotation. It was first described by Otto.1 It is a rare condition. Valentin and Müller2 were able to collect only thirty-one cases, to which they added three of their own.
This condition, as described in the literature, is due to a variety of causes. I am able to present fairly well marked examples of most of the varieties.
Case 1.—History.—A man, aged 29, complained of pain in both hip joints, which he first noticed ten years previously. It began without known cause or antecedent disease except joint pains in bad weather. At first these pains involved the hands and elbows