Abstract: In the figures, proximal centering apparatuses (4) for collar-less femur shaft prosthesis (1) which can be cemented in and which can be pushed from the medial onto the shaft (3) in the cemented region are shown. The centering apparatus (4) has at least in the medial region a centering wedge (6) which widens towards the proximal and which is connected via webs (7) to a clamping apparatus (8), with the clamping apparatus (8) being arranged in the cement-less region of the prosthesis neck (2) and being removable when the webs (7) are interrupted.

Abstract: The figures show a cementable shaft prosthesis (1) comprising a centering apparatus (2) of plastic which can be pushed on at its distal shaft end (3) and which forms a cavity (4) to the distal shaft end (3). Between the distal shaft end (3) and the centering apparatus (2) there exists a clamping connection which enables a deeper sinking in of the shaft end into the cavity in the distal direction. The clamping connection is achieved by a spigot (7) which is formed on at the centering apparatus (2) in the cavity (4) and which protrudes in into a conical bore (5) of the shaft end (3) in the proximal direction.