Abstract: A prosthetic stem insertable in an intramedullary cavity to support an articulation component includes a proximal neck portion and a distal root portion. The proximal neck is solid metal and extends for a length effective to reach into the cavity and couple to surrounding bone for load bearing engagement therewith, while the distal root portion includes a stranded cable which fills the bone cavity but flexes to avoid significant transfer of bending stresses. The cable is tightly bunched at its junction with the neck, providing a transitional degree of stiffness to its distal part which is significantly more flexible and bends to accommodate natural displacement of the surrounding bone. The prosthesis may be formed of a compatible metal such as titanium, cobalt chromium, stainless steel or the like. The prosthesis has a section modulus characterized by three distinct regions.