The Food and Drug Administration has told companies that make "metal on metal" artificial hips to take a closer look at how patients fare after their hip replacement surgery. The request involves about 20 manufacturers.
The request comes in response to an increasing number of consumer complaints about the implants, along with last year's voluntary recall of an all-metal model made by DePuy Orthopaedics, a division of Johnson & Johnson. Company officials say the company is paying for "reasonable and customary costs of monitoring" the recalled product, including the cost of surgery, if needed, to replace damaged artificial hips.
There are many varieties of hip implants, and numerous materials are used in their construction, including ceramics, plastics and metals. In the case of all metal implants, both the ball and socket of the artificial joint are made of metal. When those two parts rub together during normal wear and tear, minuscule particles of metal can shed and be released into surrounding tissue and even into the bloodstream. This can cause severe damage to local tissue, including necrosis, infection and allergic reactions.
FDA officials say there have also been rare reports of enough metal released into the bloodstream to cause problems with a patient's heart and neurological system.
Dr. William Maisel, chief scientist at the FDA Center for Devices and Radiological Health, which regulates hip implants, says there is no consensus in the scientific community about how much metal in the bloodstream is harmful.
He hopes the follow-up studies by hip-device manufacturers will help answer that question, along with a number of other queries. Specifically, the agency has asked companies to answer the following: How long do the hips last? What types of problems are patients having with the hips?
The FDA is also asking companies to collect blood samples from patients with all-metal hip implants in order to better understand exactly how much metal may be released into the bloodstream.
Dr. Joshua Jacobs, chairman of Rush University Medical Center's orthopedic surgery department and an official with the American Academy of Orthopaedic Surgeons, says it's important to remember that artificial hips are the single biggest advance of the century in the treatment of debilitating arthritis.
Prior to hip replacement, Jacobs says, patients had limited options and were often "condemned to a life of pain, immobility and lack of function." They couldn't work, he says, and couldn't participate in society.
Even amid concerns about certain models of artificial hips, Jacobs says most patients have no problems and are doing extremely well with their new artificial hips.
"The majority of patients who have these implants do not need to have them removed," he says. "They just need to make sure they have periodic follow-up with their physician."
And, Jacobs adds, they should be "mindful" of any changes like pain, numbness or swelling. If these occur, Jacobs suggests that patients visit their doctor, who will likely do an exam and take X-rays or ultrasounds of the hip and some blood samples.
Today, Jacobs says, researchers are working to develop sturdier implants that won't be vulnerable to wear and tear and will last longer than 15 years, possibly as long as 20 or 30 years.
RENEE MONTAGNE, Host:
This is MORNING EDITION from NPR News. I'm Renee Montagne.
MARY LOUISE KELLY, Host:
In Your Healthy today, we'll learn about two common surgical procedures that are causing rare but serious problems. First, hip replacements. This month the FDA asked manufacturers of metal on metal artificial hips to find out how their patients are doing up to eight years after surgery. Some of the hips have not lasted as long as expected. And in very rare cases they've broken down and caused damage. NPR's Patti Neighmond has more.
RICK DOUGLAS: (Unintelligible)
(SOUNDBITE OF DOG BARKING)
PATTI NEIGHMOND: Rick Douglas loves being with his dog, Prissy Ray, a 14-year- old Yorkshire terrier.
DOUGLAS: She loves to walk the trails and climb the rocks and everything up in the mountains.
NEIGHMOND: But Douglas can't walk his dog anymore.
DOUGLAS: I take her to the park. My friend walks the dog while I sit in the car, wait on them.
NEIGHMOND: Douglas can't work at his old job either. He was a supervisor at Wal-Mart, which required racing from aisle to aisle in the store. That's physically impossible for him now. He's in too much pain, and he can hardly put pressure on his right leg. It all started about five years ago, when Douglas got an all-metal artificial hip, intended to relieve arthritic pain. But it caused problems right away.
DOUGLAS: It kind of felt like a grinding - like metal to metal grinding inside, constant pain, burning in the side of my leg. And that's why I kept going back to the doctor.
NEIGHMOND: Eventually a specialist determined the implant should be removed and replaced. During surgery there were some grim findings.
DOUGLAS: Metal shavings had come off of the implant and went into the tissues around the hip and that the metal shavings actually petrified all the tissue, so the tissue had to be removed.
NEIGHMOND: And his artificial hip had to be screwed directly into his pelvic bone, causing chronic pain. And things Douglas used to do with ease are now difficult.
DOUGLAS: I go to the grocery store or something, I have to lean on a shopping cart, taking a lot of the weight off my hips or I can't make it around the store.
NEIGHMOND: Dr. William Maisel is chief scientist at the FDA Center for Devices and Radiological Health, which regulates hip implants. He says there's a number of questions the agency wants manufacturers to answer.
WILLIAM MAISEL: How long do the hips last? What types of problems are patients having with the hips? And we've also asked them to collect blood samples from patients with hip implants so that we can better understand how much metal is being released into the bloodstream and what affect that metal has on patient health.
NEIGHMOND: Maisel expects the follow-up studies will provide answers.
JOSHUA JACOBS: Unidentified Man: Sure.
JACOBS: Unidentified Man: No.
NEIGHMOND: At Rush University Medical Center in Chicago, orthopedic surgeon Joshua Jacobs examines a patient who just received an artificial hip that more and more doctors are using - a metal ball and socket with a plastic lining to minimize the shedding of metal particles. Dr. Jacob says it's important to remember artificial hips are the single biggest advance of the century in treating debilitating arthritis.
JACOBS: Because prior to hip replacement, there were very limited options available for patients with end-stage osteoarthritis, so they were really condemned to a life of pain, immobility, lack of function. And particularly if this was a younger patient, they couldn't work and they couldn't participate in society.
NEIGHMOND: And even amidst concerns about certain models of artificial hips, Dr. Jacobs says most patients have no problems.
JACOBS: The majority of patients that have these implants do not need them removed and just need to make sure that they have periodic follow-up with their physician and they're mindful of any changes in the symptoms around their implant.
NEIGHMOND: Patti Neighmond, NPR News. Transcript provided by NPR, Copyright NPR.