Arthritis and injury grind down millions of joints, but few get the best remedy - real biological tissue. Kevin Stone shows a treatment that could sidestep the high costs and donor shortfall of human-to-human transplants with a novel use of animal tissue.

The use of animal tissue will stir up controversy. Compare this to eating meat almost daily though. It seems more humane to use a small amount of animal tissue for fixing ourselves only a few times in our entire lives. We kill/harvest so many animals already, they could use the parts from those animals more wisely.