The hip, implanted in 1991, had to be taken apart and rebuilt in 2002. McPherron, who performed the revision surgery, found badly worn plastic and advanced osteolysis in Workman's pelvis and in his leg bone.

The complicated surgery and the long, painful recovery that followed sidetracked Workman's career. A few months before his surgery, he was president of a company, Cryogenic Chambers in Delphi, Ind., that made freezers for use in treating industrial materials. Now unemployed, Workman was recently approved for Social Security disability.

But is the maker of the hip implant, Biomet Inc. of Warsaw, legally liable for these physical and professional setbacks?

Workman contends Biomet is and has sought damages. Lawyers acting on his behalf have fired off letters to Biomet seeking damages as high as $14.5 million. But no lawsuit has been filed, and the matter has progressed no further than an exchange of correspondences between attorneys. He has received no money from the claims.

Biomet's lawyer says Workman doesn't have a case.

In one of the company's replies, general counsel Robert Durgin points out that the prosthesis made by Biomet worked well for eight years and was not replaced for 11 years.

He says Workman's attorneys have failed to show the product was defective or that the company was in any other way liable for his injury.

"Indeed, it is clear that Biomet products significantly improved the quality of his life for at least eight years,'' Durgin wrote.

Joel Higgins, an engineer for Biomet, said the company stopped packaging its polyethylene products in natural air (where the damaging oxidation can continue for years during storage) in 1992. They are sealed in packages containing a "neutral atmosphere,'' that is, one containing gases other than oxygen, he said.

Higgins said the fact the change was made does not mean that the polyethylene components irradiated the old way were defective.

He describes the change as one step in a series of improvements that Biomet, like other manufacturers, has made over the past decade to reduce osteolysis and make artificial hips last longer. Osteolysis has been a side effect of hip implants since they came into widespread use in the 1960s.

"It's constantly improving as we continue to work on technology,'' Higgins said. "But there will always be potential reaction to wear debris, and we will always have debris generated on the bearing surface. So from that standpoint, solving it is impossible.''

Hip problems started early

Workman's hip woes started in the early 1980s when, still in his late 20s, he fractured his left hip in a pickup basketball game at LaVille Jr.-Sr. High School. His bones may have been weakened by years of steroid treatments to control flare-ups of ulcerative colitis, an inflammatory bowel disease.

When an operation to reconstruct his left hip didn't work, he received his first hip implant in 1983. That hip worked fine until it was jarred loose by a car accident in early 1989 and was replaced with the Biomet hip in 1991.

Workman first noticed something wrong with his second left hip prosthesis around 1999, after about eight years of use. But, he said, he delayed revision surgery for three more years because he did not want to disrupt his rising career in the field of cryogenic treatment of industrial materials. He also wanted to keep a promise to coach a youth basketball team.

"Lifestyles today do not allow individuals to stop their lives because of minor to moderate pain,'' he said. "You have to keep going to the last minute.''

Workman believes Biomet and other makers of orthopedic devices should have done more to alert people with artificial hips about their risk for osteolysis.

The problem has been intensively studied within the industry, especially the role of gamma radiation in inducing polyethylene wear. But it's largely unknown to the general public, and much of the population at risk, estimated to be as high as 2.5 million patients, is not being monitored.

"Biomet and the industry could have encouraged patients to come in for exams in order to preventively minimize the problem,'' Workman said.

Paradoxical effect

Ironically, while irradiating polyethylene in air damages the surface, it has the opposite effect deeper down in the material.

It causes interior molecules to cross-link with each other, and that actually makes the plastic much more resistant to wear, said McKellop, the researcher from Los Angeles, who specializes in studying wear properties in artificial hips.

Researchers zeroed in on osteolysis as the No. 1 problem in the artificial hip industry about 10 years ago and have concentrated on improving polyethylene as a way to stop it, he said.

They have found ingenious strategies for irradiation that minimize the harmful effects of oxidation and maximize the beneficial effects of cross-linking. They have also developed artificial joints that use other materials, such as metal or ceramics, instead of plastic.

McKellop says the goal should be to reduce the rate of wear in artificial hips to the point that osteolysis vanishes as a serious health issue. Studies have shown that osteolysis rarely occurs if the polyethylene bearing surface loses only 0.1 millimeter or less per year.

McPherron said he believes Americans sometimes expect too much from medical devices, including artificial hips.

The basic purpose of hip replacements is to relieve pain and to allow people to walk moderate distances. But Americans expect their mechanical hips to enable them to do everything they could do with their natural hips, McPherron said. "In the U.S., we're one of the more demanding societies,'' he said. "We don't just want pain relief. We want to be able to do all the things we used to do."