Hip Science - Hip Replacement

Using space technology, researchers are developing artificial bones for pain-free hip replacement implants.

79-year-old Bob Hayes has heard all the statistics.

There are more than 300,000 knee and hip replacement surgeries performed each year in the United States. Sixty-five percent of hip replacements and seventy-two percent of knee replacements are received by people over the age of 65. Because the U.S. population is aging, the number of hip fractures is expected to exceed 500,000 annually by the year 2040. The average hospital stay for a knee or hip replacement: 5 days followed by four weeks using a walker.

Bob, a retired veterinarian from Golden, Colorado, knows the statistics because he's one of them. Between 1978 and 1999 Bob had two hip replacements and five revisions. "I kept three or four of them as mementos," he laughs. "I've been thinking of using them as bookends."

Bob's sense of humour is still intact, but the pain is no laughing matter. "You go until you can't stand it anymore," he says, "and then you have surgery again." And again and again.

"The problem that faces medicine today is that the current implants last only about ten years," explains Dr. Frank Schowengerdt, a friend of Bob's and director of the Centre for Commercial Applications of Combustion in Space (CCACS) at the Colorado School of Mines. (CCACS is a Commercial Space Centre managed by NASA's Space Product Development program.) "Surgeons cut out the old joint and glue in a new one," continues Schowengerdt. "Time along with wear and tear cause the glue to deteriorate."

Learn more about hip replacement surgery from MEDLINEplus. A normal hip (left) and an artificial hip implant (right).

Bob recalls his own experiences: "The glue would loosen and the joint would pinch a nerve. The pain was intense."

Putting an end to that kind of suffering is what motivates Schowengerdt and colleague Dr. John Moore. They're working at CCACS to make better artificial bones from ceramics - implants so much like the real thing that they could actually meld with living bone. Such implants wouldn't come loose and need to be replaced so often.