The surgical treatment of idiopathic osteonecrosis of the femoral head.

The results of surgery in the treatment of osteonecrosis of the femoral head are analysed and discussed. Medullary decompression by the forage biopsy technique in the early stage facilitates normalisation of the intramedullary pressure and breaks the vicious circle constituted by ischaemia-oedema-increased medullary pressure-ischaemia which eventually produces bone death. Flexion osteotomy is indicated in the advanced stage (Ficat stage 3) provided certain parameters are respected such as the age of the patient, the stage of the lesion, the extent of the necrosis and the absence of secondary arthritis. For cases classified as Ficat stage 4, the only solution is total arthroprosthesis.