When some people look at implant makers like

Biomet

(BMET)

and

Zimmer

(ZMH)

, they see a lot to complain about.

Every year, the medical device companies promote new joint implants and surgical techniques aimed at improving hip and knee replacements. Industry-sponsored studies typically show a high success rate for the new procedures.

But critics say the industry is merely creating the illusion of success by controlling scientific research and avoiding steps that would pool independent data on surgery outcomes. These people say the industry has been miserly in its research-and-development spending, and that as a result implant science has advanced little in four decades. Yet even amid these questions about how well their devices work, the companies continue to make a bundle.

"Industry is proposing new designs and new technologies almost every day, with increasing costs," Italian physician Paolo Gallinaro wrote in the journal

Orthopedics

this year. "However, no real progress has been made."

Zimmer didn't immediately return a call seeking comment, but Biomet's founding CEO, Dane Miller, rejects the notion that the companies have fallen short. He defends the durability and usefulness of his company's products, as well as the industry's stance on data sharing.

Nonetheless George Cipolletti, who once oversaw knee implant research for

Johnson & Johnson

(JNJ) - Get Report

, holds a similar view to Gallinaro's.

"We all sell our products, to some extent, based on unsubstantiated premises," says Cipolletti, who, together with two other Johnson & Johnson alums, now runs a competing company, closely held

Apex Surgical

. "If we had to base it on clinical data, there would be a lot fewer designs out there."

In this fourth of five articles exploring apparent conflicts of interest in the medical business,

TheStreet.com

looks at the implant industry's marketing-intensive focus -- and the costs borne by patients and taxpayers alike.

Catch Phrase

Right now, the new catch phrase -- especially at Zimmer -- is "minimally invasive surgery."

Zimmer is, in fact, banking much of its future on the new technique. Already, the company has spent large sums training hundreds of surgeons to use MIS when implanting its devices. And in theory, at least, MIS does sound attractive. After all, the procedure -- with its smaller incisions -- seems like it would cause fewer complications than traditional surgery. And industry-sponsored research has backed up such assumptions.

But a rare independent study, conducted by orthopedic surgeons at Stanford University Hospital, found no significant benefits to MIS at all. Patients who underwent MIS spent about the same amount of time in the operating room as those who opted for traditional surgery. They experienced similar blood loss and transfusion rates. And they stayed in the hospital just as long and felt about the same when they finally did leave.

Moreover, the study found, MIS patients suffered more serious complications. Following surgery, they proved more vulnerable to wound problems. They also faced bigger setbacks -- such as poor implant positioning and fit -- that could trouble them down the road.

The researchers saw clear reason for alarm.

"If other studies of the mini-incision technique also show more component malposition and more serious post-operative complications than the standard-incision technique, then the long-term results of the mini-incision arthroplasty may be jeopardized," they wrote in the

Journal of Bone and Joint Surgery

. "Until the safety and efficacy of mini-incision total hip replacement are confirmed in the peer-reviewed literature by other investigators, we are concerned about the widespread use of the technique."

Popularity Contest

So far, at least, MIS has yet to achieve the popularity that some -- like Zimmer -- tend to celebrate.

Robert Bourne, chairman of the Canadian joint registry, says that fewer than 10% of hip and knee replacements currently involve the new technique. He also says that nobody really knows, yet, whether MIS implants will perform as well or last as long as traditional devices.

"That will be very important data," he says. But right now, "there's a lot of hype in the marketplace without a lot of substance."

TST Recommends

As it stands now, however, the U.S. has limited access to scientific data on joint implants in general. Despite recommendations to start a joint registry here -- and a feasibility study launched years ago by the American Association of Orthopedic Surgeons -- the U.S. remains without one.

Bourne hopes to see that change. He says that joint registries have helped other countries already. Since establishing the first joint registry in 1979, he says, Sweden has seen its rate of "revision" surgeries on senior citizens -- needed when original implants fail -- drop to just 6%. In contrast, he says, the revision rate on U.S. Medicare patients remains three times that. That rate is also higher than the revision rates in other countries, like Australia and Canada, that have registries of their own.

"Just about every first-world country except the U.S. has one," Bourne says. "I think it would be a great thing" if the U.S. followed suit.

But Miller of Biomet stops well short of endorsing a joint registry that would document actual surgical outcomes.

"Unfortunately, the results of a registry could be misinterpreted if people are not careful," Miller says. "I think we need to be careful that a registry doesn't become a shopping list for plaintiffs' attorneys."

Cipolletti, for one, sees other motives.

"There are very big dollar reasons for large companies to try to prevent it," he says. "They have a real vested interest in keeping the status quo the way it is."

Money Game

For one thing, industry insiders say, revision implants cost even more than the originals.

Medicare pays a capped rate -- around $2,500 or so -- for primary implants, they say. But it establishes no such cap, they say, for revisions that often sell for at least $5,000 more.

"The companies make a lot more money on those," says a salesman for one of the major implant makers. "It's all money-driven."

Others go so far as to claim that most popular implants are almost designed to fail. When creating the devices, they say, most companies rely very little on the science -- known as biomechanics -- that would enable them to create an implant that actually matches a patient's true physiological condition. Instead, they say, the companies crank out devices that, if anything, work opposite of human joints.

Edmund Chao, director of the orthopedic biomechanics lab at Johns Hopkins University, has highlighted this very problem. He says that current implants are designed to place the "load" -- or the pressure of a patient's weight -- on the inside of the bone instead of the outside like normal anatomy. As a result, he says, the bone can remodel itself in an effort to adapt to the new arrangement -- eventually wearing away -- and cause the joint replacement to fail in the end.

Miller of Biomet says his company's products hold up extremely well. Indeed, he puts their long-term success rate in the "upper 90% range." He also says that Biomet has made a number of significant advances, ranging from improved bone cementing to enhanced surgical techniques, over the last few decades.

Still, few seem willing to discuss the science behind this apparent problem.

"You would think that orthopedic surgery would have biomechanics as a fundamental prerequisite, much like civil engineering is needed to design a bridge," Cipolletti says. "Yet many surgeons have little or no knowledge of the subject. This void could be filled by the implant companies, but instead they inundate the surgeons -- and, now, the patients -- with marketing hyperbole."

Ethics 101

To be sure, the big device makers have no problem selling their implants.

Increasingly, however, they have come under fire -- and government scrutiny -- for some of the tactics they use. Orthopedic surgeons themselves have actually raised concerns.

David Apple, a section editor at

Orthopedics Today

, worries about even some routine practices in the industry. Specifically, he sees ethical problems with certain contracts, inked by implant makers, that offer surgeons financial rewards or suggest that they use specific products.

Two years ago,

Clinical Orthopedics and Related Research

published an entire report about ethical problems in the industry. The journal complained that device makers offer surgeons generous gifts -- ranging from ski trips to stock options to outright cash -- that could sway them to use products that may not be in their patients' best interests.

The Justice Department has since begun examining cozy relationships inside the industry. And many insiders believe the government could eventually uncover plenty.

Different Angle

Some companies, like Cipolletti's, do emphasize product design -- specifically based on biomechanics -- more than marketing.

Cipolletti says that he and his colleagues, all engineers, often felt frustrated by the lack of focus on an implant's actual performance when they worked for Johnson & Johnson. So, he says, when Johnson & Johnson acquired DePuy -- and then moved the implant division to another city -- the trio decided against relocating and launched Apex Surgical in the late 1990s instead.

So far, Apex has yet to be in business the decade necessary to track the long-term success rate of its products. However, Cipolletti says, the company has seen its implants regularly escape a major problem -- dislocation -- that tends to surface early.

He calls dislocation an "awful" experience for the surgeon as well as the patient. But, he says, at least one surgeon who uses his implants has stopped worrying about the problem at all. Indeed, he says, all of his customers have welcomed the company's new -- if less hyped -- design.

"The doctors who use it regularly -- although there are not very many -- say they wouldn't change back," he says.

To be fair, Cipolletti says that other companies have relied on biomechanics to design sound implants as well. However, he is still waiting for the big players to follow suit and bring about real change.

"If a

Stryker

(SYK) - Get Report

or a DePuy sold a device like this, the adoption rate would be much faster," he says. "But 10 years from now, I really think that people will be asking, 'How did I ever recreate hips properly before?'"