Beth Soltero, a medical researcher who underwent a failed metal-on-metal hip replacement, could wind up as a case study herself.

Soltero chose a premium metal hip, marketed by Johnson & Johnson's ( JNJ - Get Report) DePuy, because it was supposed to last longer than older plastic joints. The metal devices carry higher prices, too, boosting profits for the companies that sell them.

But Soltero sensed problems with her own metal hip from the start.

First, she developed a cyst in her abdomen four years after her surgery. She had that drained, only to see a bulge surface in her thigh. She had that massremoved, too, after it grew so large she could see it through her pants leg.

"It went all the way to the joint," she says. "That's when my doctor said, "I think it's your hip."

So Soltero started bracing for removal of the device and a painful revision surgery. In the meantime, she used her skills as a researcher to begin combing through the medical literature for reports of similar problems.

She found little beyond a recent Korean study on metal-sensitive patients whose metal DePuy-made hips had failed. The authors called for further investigation of the matter. In the meantime, Soltero heard that she is now among three patients treated by the same orthopedics practice who wound up with masses after receiving metal hips made by DePuy. She worries about failures and other possible problems.

"I don't know if the other cases ever got reported to the manufacturer," she says. "I don't think I'm going to be one in a million. ... I think the number is going to be higher than they know -- especially if nobody's reporting any of these cases."

DePuy failed to answer questions about its metal-on-metal hips for this story.

Like drug manufacturers before them, orthopedic device makers have been scrambling for new ways to grow -- and attracting some criticism in the process. Big implant companies have been accused of developing devices that seem like gimmicks at best -- and health threats at worst -- as they seek to reignite their once-highflying stocks.

Today, TheStreet.com presents a three-part series that takes a closer look at some of the industry's latest offerings.

Suits Target J&J DiscsZimmer Knee's Feminine TwistJ&J Hip Attracts Anxiety

Seal of Approval

DePuy is one of several companies planning to expand its metal-on-metal offerings by introducing new hip-resurfacing systems to the U.S. market.

The orthopedic device makers hope to boost hip sales by as much as 15% by peddling hip-resurfacing systems to young patients who would otherwise postponesurgery. The systems supposedly preserve more bone than standard hip replacements while leaving the door open for full replacements in the future.

But some experts have raised questions about hip-resurfacing results.

"The Australian Hip Registry (October 2004) reported that resurfacing arthroplasty has a revision rate twice as high as conventional hip replacement in the first year after surgery," James Waddell, a Toronto-based physician, writes in an article published by the Canadian Orthopedic Association. "Discordant reports, some documenting excellent mid-term results and others documenting high revision rates both early and mid-term, are hard to reconcile."

Regardless, Britain's Smith & Nephew ( SNN) is free to sell its hip-resurfacing system in the U.S. already.

As a result, analysts see a major market opportunity for the company. They note that hip-resurfacing accounts for more than 10% of all hip procedures in markets overseas, where it is readily available, and could now result in tens of thousands of new surgeries here in the U.S.

Smith & Nephew's metal-on-metal Birmingham hip-resurfacing system beat competing products to the U.S. market after the Food and Drug Administration approved the device last month. The FDA followed the advice of the agency's orthopedics device panel, which voted 3 to 2 to recommend approval of the device after a lengthy debate last fall.

The panel accepted the results of a single surgeon's experience in Europe as evidence that the device will prove safe and effective in the hands of numerous U.S. doctors as well. That European surgeon actually invented the Birmingham system, sold it to Smith & Nephew for $121 million -- and landed a sizeable bonus when the FDA approved the device, even though it was never tested in randomized clinical trials like those that the agency normally requires for new technologies.

To be fair, Smith & Nephew supplied the FDA with results from thousands of Birmingham recipients who were helped by the device without serious complications. Even so, the agency's decision caught some experts by surprise.

One prominent university-based surgeon, who designs joint implants for competitors Zimmer ( ZMH) and Wright Medical ( WMGI - Get Report), suggested that the panel could be making a serious mistake.

"I remind you that the last time this type of data was accepted, at least that I could find, was back when the Mittelmeier hip was approved," said William Maloney, chairman of orthopedics at the Stanford University School of Medicine. "It was a clinical disaster in this country, and it doomed ceramic-on-ceramic hip replacements in this country for years. ... This is a big jump from what we're currently used to, and it potentially is a significant patient safety issue."

The Mittelmeier -- like the Birmingham -- seemed to perform well in the hands of its European inventor. But the hip chipped in patients who received them here, leading to painful failures. Some experts worry that the Birmingham could lead to problems, too, as mainstream surgeons implant them.

Connie Whittington, a registered nurse who represents consumers on the FDA panel but has no voting power, expressed some reservations.

"I don't think it's adequate," she said of data on the Birmingham, "especially in the adverse events and the prediction of potential disasters for patients who might receive this implant."

Patient Satisfaction

Smith & Nephew boasted a near-perfect success rate among Birmingham recipients in its study. Yet some experts seemed to question whether the results were as outstanding as they seemed.

For one thing, they pointed out, the company relied on a nonrandomized trial with no control group to use as a comparison. Regular hip replacements, which could have been used, often generate excellent success rates as well.

For another, they noted, the numbers may look better than they should have because the company excluded dead patients who could have suffered failures down the road.

"It would seem to me that if a patient dies, he's no longer at risk for a revision," FDA panel member Harry Skinner observed. "So that would only make the data look better. ... I think the point is that if you want to say we've lost 27 potential events because a patient has died, then we may have some bias going the wrong direction in favoring the device as opposed to, say, the worst-case scenario, which maybe you treat them all as failures. ... I feel like the truth is probably somewhere in between."

To be clear, Smith & Nephew linked none of the patient deaths to the device itself. Nor did the company report any health threats associated with the metal-on-metal system.

Still, some experts seemed concerned that the system could release even more metal ions into the body than metal hip replacements.

"Unfortunately, the study does not do a very good job of explaining to us at what value having metal ions is detrimental to our health," stated FDA panel member Choll Kim, who voted against the device's approval. "How far from detrimental are they?"

Joint Registry

A nationally renowned expert, whose research raised concerns during the Birmingham panel meeting, could help answer that question.

Joshua Jacobs, an orthopedics professor at Rush University Medical Center in Chicago, is testing the blood of Soltero and others as part of an ongoing study of possible risks associated with metal devices. But Jacobs feels that he alone can never find the answers people seek. Instead, he is pushing for a national joint registry -- an idea opposed by some in the orthopedics industry -- that could moreefficiently track the performance of individual devices.

"Most of the major industrialized countries seem to have pulled this off," Jacobs says. "There's no reason why we couldn't do this in the U.S. ... We wouldn't have to start from scratch."

In the meantime, Jacobs has found no clear evidence yet of problems with a particular implant. Moreover, he stresses that isolated failures should not "condemn an entire technology."

Soltero's own surgeon sent her samples off to Jacobs after removing her metal hip and finding another two masses right around the joint. Her doctor shipped the device back to its manufacturer as well.

Even so, Soltero expects a "completely clean" report on the implant itself, with any clues residing instead in the masses that DePuy does not have. She now feels grateful that the earlier masses surfaced -- giving her some visible warning sign -- before those deep inside her hip went undetected too long and possibly developed into far worse ailments.

Soltero finally got rid of her metal hip a few months ago, less than five years after receiving it.

Some experts now worry that young patients with newly resurfaced hips could also reject the metal and face similar, or even worse, fates ahead.

Soltero, as a medical researcher, simply wants answers for both herself and for others who might one day follow in her path.

"It was the joint of choice -- no question about it -- based on what we knew," she says. "But I would be interested to learn if the company knew anything about these adverse events beforehand.

"That's really it. I don't regret the decision I made at the time. I just want the right thing to come out of it now."