| Popis: |
The treatment of non-traumatic ischaemic osteonecrosis of the femoral head (ONFH) remains problematical and there is evidently scope to seek for a medical treatment of this disease which often leads to a surgical procedure for hip prosthesis. If we exclude the context of hemoglobin disorders, necrosis appears mainly in adults, when their limb bones contain a fatty marrow. Investigations such as intramedullary pressure measurement and transosseous phlebography suggest a disorder of the intraosseous blood circulation. Various studies in animals and man have provided arguments indicating that a kind of intraosseous 'obesity' due to hyperplasia and/or hypertrophy of the fatty tissue of the femoral marrow play a role in the development of necrosis. In this respect, the blood flow of the yellow marrow is close to ischemia, whereas red marrow flow can be very high. In various conditions, mainly hemolytic anemias, the femoral yellow marrow can convert to red marrow, which has also been described in anemias induced by blood loss. If it is not thought unreasonable to consider ONFH an 'ischemic' disease, these observations are an encouragement to attempt treatment by repeated phlebotomies. This procedure may locally restore red marrow, and then an adequate blood flow which could stabilize or even reverse the lesions if they are diagnosed early. |
