Terri Wagner-Morley was so hopeful about her new right hip.

It would ease her chronic arthritis pain, allow her to exercise, even help her lose a little weight. She had a DePuy metal-on-metal ASR hip implanted in 2008 and, at first, it worked just like she'd hoped.

"It felt great," she said. "I could move again." Her weight dropped from 219 pounds to 165 in a year.

Then she began feeling a "pop" in the hip. The pop turned to pain, making it hurt to move. By late 2009, she'd regained all the weight. Wagner-Morley's hip had failed years before it was supposed to.

Her case, like thousands of others in the United States, has contributed to growing concerns about possible damage from metal-on-metal hips. Reported problems include loosening of the hip, inflammation in the tissues around the hip, dislocation and, in some cases, increased metal particles in the bloodstream. The U.S. Food and Drug Administration has ordered manufacturers to further study the safety of metal-on-metal hips. Thousands of lawsuits have been filed.

There are various types of metal-on-metal hips, many showing no problems whatsoever. Still, some doctors are moving away from metal-on-metal hips, once seen as potentially more resistant to wear and tear than artificial hips made from other materials. Minnesota's renowned Mayo Clinic has dramatically curtailed its use of the metal devices.

Dr. David Lewallen, a Mayo orthopedic surgeon, said more data on metal-on-metal hips needs to be gathered, saying they remain a viable option for some patients. But he acknowledged the array of concerns. "That continues to be a mystery, what is going on in these patients," he said. "And that continues to be the ongoing mystery and the focus of investigation and work now."

Dr. Alan Knopf, an orthopedic surgeon who teaches at UCLA and USC, went a step further. "This metal-on-metal concept ... has lost enthusiasm in the medical community," he said.

A better hip?

Introduced in the late 1960s, modern hip replacement is a success story, said Dr. Joshua Jacobs, a professor and chairman of Orthopaedic Surgery at Rush University Medical Center in Chicago.

It has allowed people who had been condemned to a life of pain, to "return to normal lives with high levels of function." About 400,000 people in the United States have hip replacement surgery each year, Jacobs said. While total dollar amounts are difficult to obtain, Medicare alone spends about $20 billion a year on implantable medical devices. Artificial hips make up a healthy portion of that total.

Despite their overwhelming success, Jacobs said, most artificial hips have a realistic survival of 10 to 15 years. But as surgeons implant hips into younger and more-active people, they continue searching for hips that last longer.

Jacobs said three total hip systems have been most common: Hips with a ceramic-coated ball in a ceramic cup, hips with a metal ball in a metal cup and hips with a metal ball fit into a polyethylene cup.

"In 2012, we still are aware that the implants we are putting in today might not last for as long as our patients need them," said Jacobs, who is a vice president for the American Academy of Orthopaedic Surgeons. "There is always a search for our ultimate desire, which would be the lifetime total hip replacement. We're not there yet."

DePuy voluntarily recalled its ASR hip in August 2010 and has recommended that all patients have their hip evaluated by their doctor. It has set up a help line and reimbursement program. DePuy issued its recall after receiving data from the United Kingdom showing that 13 percent of its ASR metal-on-metal hips needed replacement within five years.

For DePuy's ASR Hip Resurfacing System, that "revision rate" was 12 percent. Mindy Tinsley, a DePuy spokeswoman, said 37,000 ASR hips were implanted in the United States. Tinsley said she does not know how many of those hips were implanted in Minnesota.

Even though "the majority of patients with metal-on-metal hips are doing well," Jacobs said concerns about those hips have led surgeons to look to other materials. Metal-on-metal hips once were used in about one-third of all total hip procedures, he said. Now, they make up less than 5 percent.

At Mayo, Lewallen said, doctors are looking at a metal-on-plastic hip that uses a new, harder plastic. So far, he said, the results have been promising.

"There is no perfect technology," Lewallen said. "It is a matter of weighing the advantages, or disadvantages, of a particular device."

Still waiting

An infection has kept doctors from replacing Wagner-Morley's DePuy hip, which they removed on Dec. 29. She also faces continued uncertainty about when her life will return to some kind of normal.

She is the mother of twin daughters in college and a grown son. She is living at a friend's townhouse in Rosemount. Spacers fill the place where her hip should be. She cannot walk, she cannot work. For a time, her kidneys and her liver failed.

Wagner-Morley said she just wants to get her life back.

"I'm just so happy I am alive," she said. "But it's frustrating as heck."

Broadspire, the company handling claims of DePuy patients, has indicated they will pay for Wagner-Morley's new surgery, said her attorney, Mark Karney. Still, some type of class-action lawsuit is expected, he said.

"It's turned her life upside down," he said. "All of this stuff is, in my opinion, a direct result of a defective hip."

James Walsh • 612-673-7428