This paper presents a radiographic study of Charnley hip prostheses, 100 fitted by the transtrochanteric route and controlled at a minimum distance of a 2 years and 40 by the posterolateral approach without osteotomy of the trochanter, controlled on the postoperative radiographs. For the first group, the behaviour was studied of the components, bone and cement. For the second, a comparison was made with cases operated on by the transtrochanteric route on the basis of several biochemical parameters.