A joint prosthesis system has a metal shaft, which is implanted in the femur, a throat having an outer cone, a joint ball made of ceramic and an accommodation for the throat. The accommodation has an inner cone, and a sheath-shaped adapter, which is arranged between the shaft and the joint ball in a clamping manner. Due to an exceptional elasticity and a special shaping of an inner and outer wall section of the adapter, the application of force to a narrow surface region on the metal outer cone and the application of the force into the ceramic inner cone is extensively concentrated on a load-bearing region (B) opposite the narrow surface region within the largest mass expansion of the ceramic joint ball.
