[Massive and sudden bone resorption in rapid destructive coxarthrosis. Radiologic and anatomic study].

Twenty hips with rapid destructive coxarthrosis (early form, 3; delayed form, 17) showed, during their development, a massive and sudden bone resorption. Preexisting problems of the bone structure of the hips were dispersed and constantly changing; they were different from those of common arthrosis and primary necrosis of the hip, conditions characterized by a progressive organization of the lesions in the relatively homogenous major areas. In five femoral heads sampled during the resorption, vascularization is ensured by a more or less dense network of capillaries. Medullar tissue was replaced by clumps of reticular cells, which later developed into differenciated cells (fibroblasts, osteoblasts and osteoclasts). The bone trabeculas also underwent several changes. Such tissue transformations are identical to those brought about by more or less severe experimental ischemia. In our samples, the confluence of centers of osteoclasia, very active, explains the massive bone resorption seen on x-rays.