In recent years, SPD has been increasingly applied for nanostructured high performance implant materials. In many cases, SPD can achieve high densities of deformation induced defects which harden the material without changing the Young’s modulus. The latter should be kept moderate i.e. close to that of the broken bone, in order to avoid the effect of stress shielding to the bone. Both high densities of dislocations and grain boundaries create strength values being more than 100 % higher than those of the as-cast material; even further hardening can be achieved through massive SPD induced formation of vacancies/vacancy agglomerates which, however, seems to be crucial for ductility.  Examples are given for the Ti-Nb system but also for biodegradable implant materials such as Mg alloys where the addition of alloy atoms causes too high biocorrosion rates; this suggests either (i) to use SPD induced defect generation of a material with high purity  as a hardening tool, or (ii) to design composites of Mg with other -much slowlier biodegradable- non toxic elements such as Zn or Fe, in order to account for a maximum of implants’ stability and thus a complete healing of the broken bone.