If all goes well, they’ll insert a tiny inflatable balloon into the brittle bone and then stabilize it by injecting cement. It’s a delicate procedure that deploys needles close to the spinal cord, and it takes a coordinated effort.

There’s an anesthesiologist alternating with a nurse anesthetist, an X-ray technician and a circulating nurse; there’s a pair of scrub techs to handle surgical instruments; there’s the surgeon, a middle-aged orthopedist who has never performed this type of operation before.

And, at the foot of the operating table, there’s Chuck Bates, a guy who studied biology in college and always wanted to go to medical school but never did.

Instead, he began his career selling hot dogs to grocery stores.

As the surgeon prepares to make an incision, Bates stares at the X-ray monitor.

Come up one centimeter and make your incision there, Bates tells the surgeon.

A little later, when it appears that the doctor is going to use his hand to push a needle into the patient’s spine, Bates suggests that he try a mallet instead.

Just tap-tap-tap, Bates advises.

The job wholesaling hot dogs enabled Bates to get an MBA on the weekends, and then a friend told him about a career more in tune with his interests, which led to employment with Kyphon, a manufacturer of medical devices.

Devices used to repair fractured vertebrae.

That’s how Charles E. Bates III came to be standing at a patient’s feet several years ago, doing his part to advance a new procedure called kyphoplasty.

Bates was the salesman in the operating room.

Although patients may not be aware of their presence, sales representatives have become fixtures in operating rooms across America. They come bearing artificial hips and artificial knees, cardiac pacemakers and implantable defibrillators, spinal stabilizers and mesh used to support prolapsed bladders. They deliver screws to hold bones together, and protein substances meant to make bone grow again.

At a time when Washington is trying to find new economies in health care, salesmen in the operating room serve as simple reminders that medicine is a business, with all the potential that entails to promote efficiency, boost sales and extract profit.

But should they be there at all?

In an age of rapidly proliferating technologies, the salesmen may know more about their products than the doctors who use them do.

In an environment where data is often lacking about the relative effectiveness of one product vs. another, or even about the merits of doing a procedure such as kyphoplasty at all, sales reps can tip the balance.

In the business that is surgery, they deliver devices to hospitals as needed, and they make sure the scrub techs know precisely which instruments and components the surgeon will reach for next. They speed procedures along, making time for more.

“They are critical to the efficient execution of hip and knee replacements,” said Denver orthopedist Ted Parks.

Many medical devices could not be used — or used safely — without sales reps, said David Nexon, senior executive vice president of the Advanced Medical Technology Association, an industry group.

Richmond gynecologist Catherine A. Matthews said that’s a frightening argument.

“They’re not in any way motivated to recommend what might be the best thing for the patient,” Matthews said. “They’re there to sell their product.”

Doctors shouldn’t have to depend on reps for expertise, she added.

The legislation being crafted on Capitol Hill could nudge the nation’s medical system toward new ways of doing business — making doctors more sensitive to costs, giving patients more information about what works and what doesn’t, paying hospitals based on the quality of their outcomes.

In short, it might begin to weaken the influence of the doctor-salesman relationship.

In the meantime, sales reps fill a vacuum.

Vince Proffitt knows the business well. He sells spinal implants in the Washington area, and he’s on call 24-7. If someone’s been in a car wreck, he says, timely delivery is about more than just efficiency.

The best part of the job, the father of two said, is “the fact that I can actually make a difference and help people.”

He’s talking about the patient lying “pretty helpless on that table,” but he says he’s also there for the doctor. “Any surgeon likes to have his team. And I think what we try to do is become a part of that surgical team.”

A former U.S. Air Force intelligence officer, Proffitt said he preps medical teams with attention to detail, “much like I would prepare an air crew for their mission.”

He used to work for the big manufacturer Medtronic, where he was successful enough to make the President’s Club, earning a trip to Hawaii. Now he runs his own medical device distribution firm, Spartan Medical.

On LinkedIn, he made it clear that he means business.

“My goal is to build, train, and coach a team of hard-charging professionals to gain market domination,” Proffitt said in an online profile. “Our team hunts in packs, takes care of each other . . . and believes victory is the only option.”

The key to success, Jim Rogers says, is a technique he calls “Dynamic Psychological Selling.”

An enthusiastic talker with a gleaming smile, Rogers used to be a sales executive for Wright Medical Technology, a major manufacturer of surgical implants. Then last year he founded the American Institute of Medical Sales, whose mission is training people to be salesmen in operating rooms.

The curriculum at the institute ranges from how to perform a joint replacement to how to get inside a surgical suite without an invitation.

“Excuses to use to be in a hospital without a case,” an institute brochure says.

Using hours of videotaped role-playing, Rogers teaches would-be salesmen the art of engaging surgeons in conversation. Conversations lead to relationships, which lead to sales.

Rogers coaches students to research doctors’ medical writings and hobbies, so they can break the ice with a line like this: “By the way, I read your paper on ACL reconstruction in teens. Fantastic article!”

The idea is to sell without making the surgeon feel that he’s being sold.

“If you have a good relationship with a surgeon and you can convince the surgeon to use your product, that surgeon can then convince the hospital to use your product,” Rogers said.

To win surgeons over, sales reps must demonstrate that they can save time in the operating room, Rogers says.

“A surgeon is driven on how many cases can you do in one day. They want to be able to do as many cases as they can.”

To give aspiring reps a feel for surgery, the institute used to train them on cadaver parts, but that got expensive; now students work on anatomical models called sawbones. The institute also takes trainees into operating rooms to observe surgeons and reps in action. One of Rogers’s goals is to weed out the squeamish: Some people faint at the sight of blood.

Since it opened, the institute, which also runs a recruitment service, has received 46,000 résumés, Rogers said. All sorts of people are clamoring to get into the business, he explains. Real estate agents, stockbrokers, insurance salesmen. People who have sold copiers, software and uniforms. “It’s easily the hottest industry, bar none,” Rogers said. “There are sales reps in our business that make over $1 million a year.”

(The average for those who’ve been at it for at least three years is $150,000, based entirely on commissions, Rogers said.)

Now the institute is planning a new program — a television program. The title for the proposed reality show:

“Sell O.R. Go Home.”

The presence of the salesman in the operating room has long raised concerns that it can put the interests of manufacturers before those of patients.

The issue was brought sharply into focus in 2003, when Endovascular Technologies pleaded guilty to federal charges that it covered up malfunctions of a device used to treat aortic aneurysms.

The government alleged that sales representatives were part of the coverup.

When the device became stuck in patients’ bodies during surgery, sales representatives coached doctors in an unapproved technique to remove the device by breaking it, the government alleged. Use of that approach, which a sales representative helped develop, kept malfunctions below the radar of the Food and Drug Administration, the government said.

A dozen patients died from malfunctions, and many others had to undergo more invasive surgery, the government said.

A history of controversy surrounding medical device marketing may help explain why some companies want nothing to do with a story about sales reps in the operating room.

“I would hope that you would not mention Boston Scientific in your story,” a spokesman for that company e-mailed.

Major device makers such as Johnson & Johnson, Stryker and Zimmer declined to arrange interviews for this article.

In a statement, Medtronic spokesman Charles Grothaus said that “most surgeons who use medical devices in their procedures expect a technical field rep to be present during the procedure, because they understand that the rep’s special product expertise enhances patient safety.”

“Actual medical decisions and selection of components are left up to the operating surgeon, who uses the technical representative as a real time resource in making those decisions,” Grothaus said.

Chuck Bates worked as a salesman and regional sales manger for Kyphon from 2001 to 2005. His first task, he said, was getting doctors interested in Kyphon’s procedure. Once they were interested, Kyphon would give them one-day courses in which they practiced on cadavers. Other surgeons would lead the class, but “the hands-on training was done mostly by the sales reps,” Bates said.

After bonding over that experience, some reps became so close with physicians that they stayed with them as houseguests, Bates said.

Kyphoplasty, the procedure Bates and his colleagues were promoting, competed with an older approach known as vertebroplasty. Both could be used on patients with osteoporosis, a deterioration of the bone. A key difference was that kyphoplasty employed the Kyphon balloon tamp.

Then there was the price: Kyphoplasty was much more expensive.

A 2004 article in the American Journal of Neuroradiology said that both procedures had benefits but that additional trials were needed to determine their relative effectiveness. Meanwhile, the FDA warned of potentially dangerous complications.

Bates said that he promoted kyphoplasty as a way for doctors to increase their incomes and help their patients.

A 2003 document containing internal comments from the Kyphon sales force — which was later used in litigation — shed light on other reps’ agendas.

“Nora and I have developed a strong personal friendship with Dr. Graham and his wife. We meet at least once every three weeks for dinner, etc. Result — 21 levels in April,” one representative wrote, apparently referring to the number of vertebrae on which the doctor had operated. “My goal is to have the surgeon treat and the [primary-care physician] refer cases as much for me personally as for the patient,” the sales rep added.

A second sales rep reported that he was trying to persuade surgeons to operate on more vertebrae per case.

“My one problem is that all of my surgeons except one are doing only one level on each patient. This has kept me from reaching my goal of 100k per month,” the rep wrote.

A third rep spelled out a strategy to get patients into surgery sooner. The trouble, as that rep described it, was that operations were getting postponed “and eventually the patient’s symptoms subside which translates into a cancelled case.”

Why would surgery be warranted for anyone whose symptoms went away?

Their fractures might worsen, former Kyphon reps said.

Bates said in an interview that he helped solicit business for his surgeons by donning scrubs and going to the offices of potential referring physicians.

At the company’s urging, he and other Kyphon reps taught doctors and hospitals how to maximize the money the federal Medicare program would pay, Bates said.

Although the minimally invasive procedure could ordinarily be performed on an outpatient basis, Kyphon reps recommended that patients be admitted overnight to elicit higher federal reimbursements, he said.

“The good sales reps would always make sure the physician had admitted the patient,” Bates said.

With the overnight stay, hospitals could profit from the procedure, Bates said. “The last thing you wanted to do was have them lose money and then stop doing kyphoplasty,” he said.

In 2004, Bates had a change of heart. As he recalled, he heard that hospitals in Texas were increasingly uncomfortable billing for kyphoplasty as an inpatient procedure, and the result was a decline in Kyphon’s business there. “We were afraid it was going to become a nationwide thing,” he said.

Ultimately, Bates concluded that “what we were doing was wrong,” he said, and he prepared to throw away his career.

He found his way to the Washington law firm Phillips & Cohen, which specializes in representing whistleblowers. While it was reviewing Bates’s allegations, the firm heard independently from Craig Patrick, a former reimbursement manager at Kyphon who told a similar story, lawyer Mary Louise Cohen said.

In 2005, Bates and Patrick filed a whistleblower suit against Kyphon, alleging that the company was responsible for false or fraudulent Medicare claims.

Eric Roux, a former Kyphon sales manager, said he shook his head in disbelief when he heard about the lawsuit. “From the top on down, we were never, ever told to do anything inappropriate,” Roux said. “I know the good that we did.”

Kyphon denied any wrongdoing but last year agreed to pay the government $75 million. As their reward, the two whistleblowers and their attorneys shared $14.9 million.

By the time Kyphon settled the case in May 2008, it had been bought by Medtronic for $3.9 billion. Asked to address the allegations in Bates’s lawsuit, a Medtronic spokesman did not respond.

In a news release announcing the acquisition of Kyphon, Medtronic Chairman Art Collins looked toward a bright future.

As he put it: “Kyphon’s world-class, global sales force will play a central role in the continued development of our spinal business.”