Diamonds Are A Knee's Best Friend

Diamond-and-ice knees and hips may be the artificial joints of the future. Karen Hopkin reports.

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They say that diamonds are a girl’s best friend. Well, the same jewel may be particularly useful to girls who need to have a knee or a hip replaced. Because when it comes to making an artificial joint that’s built to last, a thin coating of diamond beats titanium or stainless steel hands down. Or so say physicists at Harvard University in the August issue of a journal called Physical Review E.

The only problem with a diamond-dusted knee might be its biocompatibility. Seems the naked gem might be a bit too abrasive for use in the body. So the Harvard physicists coated the diamond with...ice. Yes, the frozen-water kind of ice. The ice layer makes the diamond coating softer and less abrasive. And because the surface of the diamond layer, sprinkled with a pinch of sodium, is a perfect fit for the crystalline structure of frozen water, the ice doesn’t melt...even at body temperature. In some cases it might even remain frozen past water’s normal boiling point, the physicists predict. Which would mean that a diamond-and-ice encrusted knee should survive even a John McEnroe style meltdown after a few sets of high-pressure tennis. (Sound clip of McEnroe melting down: “You cannot be serious! That ball was on the line!”)

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