A clinical case is reported on in which there were difficulties in removing Kirschner wires from the bone four years after arthrodeses of a shoulder. These could only be removed with great force. They displayed muff-like mantling with bone. The histological investigations revealed that the bone had deposited directly on the metal surface and that absolutely stable bonding between the bone and the metal had occurred. In connection with similar observations in the literature, the importance of this case is pointed out with regard to the cement-free implantation of endoprostheses.