Arthroplasty represents the replacement of irreversibly damaged joints using endoprostheses made of different materials. It is a problem of great medical and social interest. From the clinical experience, the need for a better adaptation of the prosthesis shape, especially to the shape of the femur, was deduced, since quite often the shape of the prosthesis does not follow the curves of the femur. Thus a mechanical conflict that can lead to thinning or even fracture of the cortex can appear. Consequently, this leads to the delay of the patient's mobilization, therefore of his/her socio-professional reinsertion. The original element of this project is to study the correlation to be made between the shape of the femoral canal, evaluated by modern imaging methods, and the shape of the prosthesis. Thus, a prosthesis will be obtained with a mechanical compatibility as close as possible to the physiological one, with an optimal adaptation of the prosthesis to the bone in which it is implanted, allowing the early recovery of the patient from a physical, mental and social point of view.