Don’t worry, the doctor told Brian Lykins’ parents, as he prepared to use cartilage from a cadaver to fix their son’s knee.

A million people a year have operations that use tissue from donated dead bodies. The nation’s largest tissue bank had supplied this cartilage. It was disinfected and perfectly safe, he assured them.

But it wasn’t.

Four days after this routine, elective surgery, Lykins – a healthy, 23-year-old student from Minnesota – died of a raging infection.

He died because the cartilage came from a corpse that had sat unrefrigerated for 19 hours – a corpse that had been rejected by two other tissue banks. The cartilage hadn’t been adequately treated to kill bacteria.

None of this broke a single federal rule.

And it could happen again today – likely is still happening today – because of shoddy practices by some in the billion-dollar body parts business and the lack of government regulation.

The industry is in the news because a New Jersey company is accused of scavenging corpses without families’ permission and then selling those parts to tissue processors. But apart from this scandal, thousands more Americans each day are put at risk in more insidious ways by legitimate tissue suppliers.

A three-month investigation by The Associated Press found problems ranging from inadequate testing for potentially deadly germs to lack of a unified system for tracking tissues as they travel from donor to recipient.

At every step – from funeral homes, where the journey often begins, to hospitals and doctors’ offices, where it ends with patients receiving the eyes, bones, skin and other parts of the dead – poor oversight invites abuse and creates danger.

Most tissue transplants involve reputable companies and do a lot of good. Olympic skiers, people who have lost eyesight and children born with bad hearts are among the millions who have benefited. But when things go wrong, the consequences are horrific.

Ken Alesescu died May 14 in his San Luis Obispo, Calif., home, victim of a fungus-infested heart valve.

Alan Minvielle of Santa Cruz, Calif., lost a job and almost lost a leg to gangrene from a bad tendon.

Bonny Gonyer in Chippewa Falls, Wis., has pain and walks with a limp because of tainted tissue.

“It angers me when I read these stories,” Pam Alesescu, the heart valve recipient’s widow, said in an interview shortly before he died. “My kids are losing their dad, and I am losing my husband.”

The federal agency responsible for tissue safety, the Food and Drug Administration, is well aware of the problems. Yet, many experts believe the rules the FDA enacted last year as a long-promised overhaul fall short of providing the level of oversight needed.

Each year, another germ is found to spread through tissue. Each year, the FDA inspects a smaller percentage of tissue businesses.

When it does inspect, public health isn’t always protected. In 2003, an FDA inspector saw that Biomedical Tissue Services – the now-notorious New Jersey company – wasn’t documenting what it did with tissue unsuitable for transplant. The FDA let the matter drop after the company sent a letter saying it had fixed the problem. For two more years, thousands of people received tissue.

“I’m not surprised that a BTS [incident] occurred. And there will be others,” said Areta Kupchyk, a former FDA lawyer who drafted rules that ultimately were adopted in watered-down form. “We continue to be at risk.”

Here are some of the ways:

. A trade group, the American Association of Tissue Banks, requires accredited members to follow high standards, but without the FDA doing the same, hospitals and doctors can buy from unaccredited suppliers that offer tissue quicker or cheaper.

. Tissue isn’t tested as thoroughly as blood is for infectious diseases.

. The FDA sets no limits on age or health of donors, or how long after death tissue can be taken.

. Funeral homes don’t have to report deaths to organ procurement groups, leaving them outside a regulatory system and able to cut side deals to supply body parts.

. Doctors often know little about the origins of tissue they use. Some hospitals buy it like surgical gloves and other supplies – based on price and availability. Patients are not always told they are receiving tissue from a cadaver or offered alternative treatments.

. Hospitals and doctors do not have to report tissue infections to health officials, and evidence suggests that many are missed.

. The FDA requires no medical training to run a tissue bank or procure tissue.

And business is booming.

The number of tissues distributed for transplants rose from 350,000 in 1990 to 650,000 in 1999 and 1.3 million in 2003. Tissue companies are awash in cash – even the nonprofits. The biggest is the Musculoskeletal Transplant Foundation Inc. of New Jersey. In 2004, it had $243 million in revenues and paid its chief executive $542,212.

The FDA, on the other hand, lacks staff and money. It spends $5.4 million a year on tissue regulation – less than two days’ revenue for the industry. Inspections of tissue businesses peaked at 285 in 2004, but the number of companies rose from 1,325 two years ago to 2,030 now.

However, many gaps in oversight have nothing to do with resources, and stem instead from an FDA and Bush administration philosophy of not wanting to burden industry.

The FDA rules often state broad goals and let industry decide how to meet them. They say tissue should be tested for germs but do not specify the type or level of testing. Ditto for how tissue is disinfected. Some tissue, in fact, is not disinfected at all.

An FDA quality and compliance official, Mary Malarkey, said she believes tissue is safe and that she would have no qualms about receiving it.

“I do actually have family members and friends who have,” Malarkey said. “I take that very seriously.”

The trade association’s president, James Forsell, said that most big companies are association members and that consumers are protected by his group’s accreditation process.

When Lykins and others received contaminated tissue a few years ago from the Georgia-based bank CryoLife Inc., that company was not accredited. Now it is, and company officials say they have several new testing and treatment procedures to prevent such problems.

If a nonmember such as BTS wants to falsify records or ignore proper procedures, “there is precious little that can be done,” Forsell said.

Even doctors don’t understand the risk of tissue they are using. “It comes in a nice package, it looks sterile,” said Dr. Matthew Kuehnert, a tissue safety expert at the federal Centers for Disease Control and Prevention.

“Most physicians don’t even know the questions to ask,” said Dr. Ty Endean, a Tucson, Ariz., orthopedic surgeon. “They order tissue and they leave it up to the surgical center at their hospital. And those people are just going on price.”

Often, the people who order tissue for operations don’t know how it was treated or even all the companies that handled it. When the BTS scandal broke, some hospitals did not even realize their tissue had come from an unaccredited supplier.

Kuehnert wants a uniform system to trace tissue instantly from donor through processors to recipients.

“This is a daunting task, but it is doable,” he said.

It’s doable if people want it, says Steve Lykins, father of the Minnesota student who died.

“What the tissue companies did when Brian died was legal. The problem was, there were no laws out there to break,” he said. “Any one of us could have opened a tissue bank in our garage. We could have hired the neighborhood kids who were interested in science to work for us.”

Lykins and his wife, Leslie, have made many trips to Washington, lobbying for change.

“We didn’t want to be sitting around watching TV and hear of another case where someone had lost a son like we lost Brian and know that we didn’t do anything about it,” he said. “We worked very hard for quite a while to encourage the FDA to start regulating this industry.”

AP writer Adam Goldman in New York, medical writer Lindsey Tanner in Chicago, biotechnology writer Paul Elias in San Francisco and researcher Rhonda Shafner in New York contributed to this report.