Modifications of the Subchondral Bone in Aseptic Osteonecrosis of the Femoral Head

Inclusion Criteria for experimental group: * Men * Patients aged from 25 to 70 years * Patient with an aseptic osteonecrosis of the femoral head established by medical Imaging (CT-scan, MRI or radiography) * FICAT stage 3 or 4 * osteonecrosis etiologies : alcohol, corticosteroid therapy, idiopathic * Surgical indication of hip prosthesis determined Inclusion Criteria for control group: * Men * Patients aged from 40 to 70 years * Patient with a primitive coxarthrosis * Surgical indication of hip prosthesis determined Exclusion Criteria for the 2 groups: * Other causes of osteonecrosis (coagulopathy, barotrauma, trauma) * Prior fracture of the upper extremity of the femur * Prior cancer and hematological malignancies with bone locations * Prior debilitating bone diseases * Patient refusal to participate in the study * Patient who isn't affiliated to a social security regimen