The invention relates to a joint prosthesis having a bending hinge which is formed by a hinge fork and an axle pin (4) which comprises two axle stubs (42 43) which are arranged in an installation position for insertion in which installation position the axle stubs are retracted in a coupling piece (3) and in an expanded position after implantation by movement in the axial direction into aligned hinge holes of the hinge fork wherein the axle pin (4) has two bearing areas (41) at the ends of the axle pin and a joining area (40) lying therebetween and the axle pin is separated in the joining area (40) along a plane (49) extending in the axial direction which plane intersects with the jacket of the axle pin (4) at two points.
