implant composition need not be a single substance indeed it is envisioned that compositions comprising blends of two or more substances will be suitable suitable blends include combinations of polymer fibers dispersed in resins such as delrin af a blend of ptfe fibers uniformly dispersed in delrin acetal resin polymer research has resulted in the development of scores of high grade polymers these polymers have physical properties that cover the entire range of properties such as durability and hardness from metallic and plastic accordingly it is envisioned that many other compositions will be suitable for use with this implant so long as these compositions have the desired properties it is also contemplated that multiple substances can be combined to form a hybrid implant combining the advantageous properties of each substance for example more durable substances can be combined with more flexible substances high coefficient of friction substances can be combined with low coefficient of friction substances these substances can be placed in specific portions of the implant where the corresponding property is most critical alternatively the substances can be blended together in a uniform ratio throughout the entire implant also while post operative imaging fluoroscopic magnetic resonance imaging etc is not needed for proper placement of the implant imaging may be desired for special purposes in such cases an opaque structure can be imbedded into the implant or an opaque substance added to the polymer for the purposes of imaging it is important to note that in cases where the bone surrounding the implant is protected from wear then harder more durable materials can be used including metal alloys for example biotechnological techniques to stimulate growth of.