Researchers at Duke University Medical Center have created a three dimensional woven scaffold that could be impregnated with a recipients own stem cells to create functional cartilage. From the article:
In laboratory tests, the fabric scaffold that the researchers have created had the same mechanical properties as native cartilage. In the near future, surgeons will be able to impregnate custom-designed scaffolds with cartilage-forming stem cells and chemicals that stimulate their growth and then implant them into patients during a single procedure, the researchers said.
via medGadget
I'm not too picky ... I'd accept a magic pill that repaired all decaying bones and joints as well.