[Experimental steroid osteonecrosis in rabbits and pathologic findings].

Osteonecrosis of femoral head was experimentally induced in adult rabbits by employing a combined protocol of hypersensitive vasculitis and administration of high dose corticosteroids. By using India ink introartery infusion microangiography and pathologic examination, we found that the damage of terminal arterioles and interruption of blood supply of terminal arteriole was causative pathogenesis. In the early phase, the haemopoietic necrosis and enlargement of fat cell in the bone marrow occurred. The perfused arterioles decreased, especially in the subchondrol bone. In the later phase, the osteocytes showed necrotic fibrosis in bone marrow. The perfused arterioles increased gradually and repairtive changes began.