The prosthesis has a spindle element (4) arranged in a bore of a stem-anchoring element (3) for lengthening the prosthesis. The spindle element and/or the drive is inserted and removed again after implantation. A diameter of the bore is large with respect to force applied for lengthening the prosthesis. A drive (5) e.g. piezoelectric motor, of the spindle element is integrated in a joint replacement part (1). A threaded element (8) and/or a screw (9) with a thread serving as a mating piece for the spindle element is inserted into the bore. The prosthesis has a modular structure. The threaded element is made of a ceramic material or plastic material.
