[Idiopathic necrosis in the marrow of the distal femur. A contribution to aseptic necrosis of the bone (author's transl)].

Symmetrical aseptic necrosis in the marrow of the distal femur was systematically examined in 4 autopsies. According to formal analysis, the self reliant process, with a tendency toward relapse begins with two forms of destruction of the medullary fatty tissue. The consequences are fundamentally the same as those present after necrosis of the extra-medullary fatty tissue; there are only modifications caused location. These modifications include the regular calcification of non-liquifying by fatty-tissue necrosis that fibroses in a net-like manner, and of subsequent bone formation. Spongiosis in incorporated secondarily into necrosis. Medullary necrosis are not caused by vascular lesions and differ therefore from infarct-like necrosis of the bone. The etiology of the medullary steatonecrosis, which probably begins dystrophically, cannot be cleared up morphologically, and is unknown up to now. There are no definite indications for a causal relationship with cortico-steroid therapy. This form of necrosis of the marrow is therefore termed "idiopathic".