Rapidly Destructive coxarthrosis (RDC) has been reported these twenty years by a lot of authors. According to some papers, clinical findings of RDC has not changed so much and histopathological findings are now in consistent with femoral head necrosis, but X-ray findings of RDC at its initial stage and late stage are not in total accord. We experienced two cases that seemed to be RDC in the last six years. It might be said that nature of RDC is avasculan necrosis occurring with proliferation of sinovium at early stage and besides mechanical and immunological factors, bone fragments and crystals freed from exposed subchondral bone might accelerate joint damage by interacting with sinovium and causing release of destructive factors as well as synovial proliferation. In addition, we studied two cases of osteoradionecrosis that reached similar advanced stage clinically and radiologically to that of RDC.
