The invention pertains to a self-supporting three-dimensional metal open cell foam structure, the structure having cells with openings having a diameter of between 200 pm 5 to 750 pm, for use as a bone prosthesis in cranial surgery, wherein the structure has a porosity of 50% to 95% and a thickness between 0.5 mm and 5 mm. The invention also pertains to the self-supporting structure as such, methods for producing such a structure and
