Abstract: An endoprosthesis for a cement free anchorage in a bone having a longitudinal direction comprises a prosthetic shank to be secured in the bone in the longitudinal direction of the bone. The prosthetic shank has a proximal end and a distal end and includes three plate-like blades arranged in parallel and presenting a cross-sectional profile that has an open configuration. A first one of the blades constitutes a central web and a second and third ones of the blades constitute side walls which enclose, at least partially, the central web and extend, at least partially, in parallel, in a direction of the central web. The prosthetic shank further includes bridges connecting the side walls with the central web. A region adjacent the distal end of the prosthetic shank is in the shape of a scoop and the blades are joined at least at the distal end to form a common cutting edge. A collar including a pin for receiving a ball joint is attached to the proximal end of the prosthetic shank.