Prosthetic component adapted to be implanted in use at a patient's bone, such as a tibial component (1) of a knee prosthesis adapted to be implanted at one end of the patient's tibial bone at a knee joint, comprises a body provided with a bottom surface (1b), adapted in use to face the patient's bone, wherein the prosthetic component comprises an intermediate device (20), placed in use between the bottom surface (1b) of the prosthetic component and the patient's bone, adapted to stably constrain the prosthetic component to the patient's bone.