In this study, the aim is to identify the modifications responsible for aseptic osteonecrosis of the femoral head and its structural evolution by the association of the micro scanner analysis and Raman spectrometry performed on the femoral heads removed during hip replacements. The study of femoral heads will allow the analysis of bone tissue at two different scales, both correlated with the biomechanical properties of the bone. Also, the association with preliminary MRI analysis will provide pathogenic explanations correlated to these modifications.