Stryker, the main company making the ceramic hips, disagrees strongly that there is a problem with squeaking, and says that the new hips won't shatter. Patient and surgeon/physician reports say otherwise about the squeaking; as of yet, no one knows about shattering.
The hip joint is a tricky one anyway. It is a ball-and-socket joint, which is one of the reasons it wears out in many people. It also has a lot of stress on it, as it carries the body's weight with every step. It also has a large ball in a large socket, and a relatively small connecting bone to the femur. (So much for "intelligent" design, eh?)
Here is part of the story from today's New York Times:
The first time John L. Johnson’s artificial hip squeaked, he was bending down to pick up a pine cone in his yard in Thomasville, Ga. Mr. Johnson looked up, expecting to find an animal nearby.
Susan O’Toole, a nutritionist at Montefiore Medical Center in the Bronx, who first squeaked going up stairs after getting home from her hip-replacement surgery in 2005, said she thought the banister she was gripping needed repair.
And Edward Heary, an apprentice appraiser in Hatboro, Pa., said clients sometimes look with embarrassment or concern at their floorboards when he walks though their homes.
As all three patients — and hundreds of others — discovered once they pinpointed the source of the noises, they had become guinea pigs in an unfolding medical mystery. Their artificial hips are made of ceramic materials that were promoted as being much more durable than older models. But for reasons not yet fully understood, their hips started to squeak, raising questions about whether the noises herald more serious malfunctions.
“There is something amiss here,” said Dr. Douglas E. Padgett, chief of adult reconstructive and joint replacement service at the Hospital for Special Surgery in New York. More than 250,000 Americans get total hip implants each year, a procedure that generally costs close to $45,000.
Any artificial hip can occasionally make a variety of noises. But until Stryker, a medical products company, began marketing highly durable ceramic hips in the United States in 2003, squeaking was extremely rare.
Now, tens of thousands of ceramic hips later — from Stryker and other makers that entered the field — many patients say their squeaking hips are interfering with daily life. One study in the Journal of Arthroplasty found that 10 patients of 143 who received ceramic hips from 2003 to 2005, or 7 percent, developed squeaking. Meanwhile, no squeaks occurred among a control group of 48 patients who received hips made of metal and plastic.
Beyond annoyance and embarrassment, many patients and their surgeons fear that the squeaky ceramic hips may signal that the joints are wearing out prematurely. That could force patients to undergo the very operation — a second replacement of the same hip joint — they had hoped to avoid by choosing ceramics.
Last fall, the Food and Drug Administration issued a warning to Stryker, saying it had failed to take the steps needed to prevent squeaking and other problems.
Stryker says that none of the problems underlying the recall or the warning letter from the F.D.A. reflect problems that cause squeaking, which it contends occurs in less than 1 percent of implants.
Whatever the actual frequency, some investigators who have looked at the problem say the squeaking seems to be associated with extreme flexing of the ceramic implants, but exactly how is unclear. In X-rays, many of the squeaking hips appear to be perfectly aligned. Nor is there a clear relationship between squeaking and hip pain or other conditions some patients say they have encountered, like the sensation that the hip disengages slightly when a patient walks.
Some patients squeak even they are walking normally, like Ms. O’Toole or Michael Mueller, a software executive in Scottsdale, Ariz. Mr. Mueller is so frustrated with squeaks, pain and popping noises for which he blames his ceramic hip that he has displayed his problem on YouTube.
Click on the YouTube link. This isn't a little thing, it's with every damned step; and it would drive me barmy.
Here's more from the Times:
While there have been no reported cases of serious mishaps, some surgeons fear that the ceramic material might shatter at some point, leaving a patient with so many inflammatory shards in the hip that a doctor could never find them all.So, who do we believe? The company with a vested interest in keeping its much-hyped replacement joint on the market, or the docs (who've been doing hip replacements for years) and their patients (who had looked forward to not needing a replacement hip replacement in ten years or so)?
“It is important to keep this in perspective,” said Aaron R. Kwittken, a spokesman for Stryker. “Published research shows squeaking is rare compared with other total-hip-related risks like infection, dislocation and leaving patients with uneven leg length.”
But plaintiffs lawyers, who have already filed scores of lawsuits on behalf of ceramic hip patients, are gearing up to argue that squeaking is not a minor problem for many who experience it.
(There is more at the NYT link. - CS.)
Did the FDA speed the product through too quickly, without enough studies? To be fair, the FDA has sent two warning letters to Stryker about the problem. One of them can be found here: According to the letter, Stryker knew about an increase in complaints, but didn't implement any corrective or preventative actions. Hm.
It sounds like US healthcare consumers are getting the short end of the stick yet again. The irony is that the people who usually get the short end in healthcare (the uninsured) are likely to have dodged this particular bullet.
Someone needs to step up here and do some studies. Someone not associated with the companies manufacturing the ceramic hip. Stat.