For cemented stem anchorage, the VEKTOR-Titan is a prosthesis system which cannot be beat. A three dimensional cone-shaped proximal allows for particial filling of the metaphysis, which stabilizes the implant and prevents it from sinking. The lateral side and ventral dorsal side have longitudinal fins. These offer high rotational stability when inserted into stable proximal spongiosa as a spongiosa thread might be. Parable-shaped cavities located between the bridges conserve the supplying vessels in the bone as well as the local spongiform structures. Diaphysis femurs are filled in without an anatomical shape. A proximal anchorage is provided by stem shape and implantation techniques. Proximal bone atrophy is no longer an issue because the metaphyseal spongiosa and bone are avoided by this device.