WASHINGTON — The U.S. Supreme Court has declined to hear a lawsuit in which a woman accused Medtronic of encouraging doctors to use the company's controversial bone-graft product Infuse in ways not approved by the U.S. Food and Drug Administration.

Patricia Caplinger of Oklahoma is one of about 6,000 people suing the medical devicemaker for injuries they say are related to Infuse. Medtronic said that because the FDA approved Infuse for use in specific types of operations, the company can't be sued under state consumer-protection laws for nonapproved uses — even if a Medtronic representative was in the room during surgery.

Without commenting on the issues in question, the Supreme Court on Monday denied Caplinger's petition for a hearing. Medtronic did not comment on the legal victory.

Medtronic has booked billions in sales of Infuse since it became legal to sell in 2002, but many patients have had problems after receiving the product. Thousands of these patients are weighing settlement offers from Medtronic, and Monday's news may motivate them to accept relatively small sums as settlements.

Caplinger had asked the court to reconsider whether Medtronic could be sued under state laws for promoting Infuse for uses that the FDA never judged safe and effective. Infuse includes a novel druglike compound originally derived from human cells that causes bone to fuse rapidly after surgery in the lower spine, tibia and face.

In an earlier case — Riegel vs. Medtronic, in 2008 — the Supreme Court gave medical device companies broad immunity from liability for almost every use of a product if the FDA had approved it for any use. Lower-court judges in Caplinger's case relied on that reasoning when they granted Medtronic's motion to dismiss the case.

The company argued that patients injured by off-label uses don't have grounds to sue Medtronic under state law because doing so violates a legal dictum called pre-emption, which says federal laws supersede state consumer-protection laws. Pre-emption, Medtronic says, is necessary to let devicemakers develop new patient treatments.

"State-law claims like [Caplinger's], which seek to impose requirements on a device beyond the FDA's, are expressly preempted," Medtronic argued in a brief to the Supreme Court last month. "Although [Caplinger] argues that [federal law's] broad preemption provision is inapplicable when a plaintiff alleges off-label use, no court of appeals has adopted that theory, which is inconsistent with this Court's decision in Riegel."

Allison Zieve, one of the attorneys who brought the case for Caplinger, said it doesn't make sense to bar patients from suing when a company promotes a use for a product that hasn't been studied by the FDA.

"It's totally illogical and certainly not just," Zieve said.

It's legal for doctors to use devices in unapproved ways as long as they have a sound reason for doing so and they disclose the risks and alternatives to patients. Off-label use of Infuse has been estimated at 85 percent in several patient injury lawsuits.

While thousands of patients have alleged Infuse-related injuries from off-label use, many state and federal judges have ruled, based on Riegel, that pre-emption does not allow those injured patients to sue Medtronic. Judges who have let Infuse personal-injury suits proceed have ruled that state laws invoked don't supersede federal laws, but run parallel to them.

"It's a complicated problem because Congress tried to balance the interests of those injured by FDA-approved devices and those who would suffer if doctors are discouraged from innovation," said David Prince, an Infuse product liability expert at Mitchell Hamline School of Law in St. Paul.

The FDA, Prince added, has never adequately drawn the line between manufacturers' disclosure of information about off-label uses and manufacturers' promotion of those uses.

As a result, "humans are suffering with no way of being compensated," he said.

That could lead to future attempts to get off-label promotion cases before the justices, said Max Helveston, a pre-emption expert at DePaul University's law school in Chicago.

The way the law is being interpreted, Helveston said, the courts are saying that a single narrow approval gives device makers "free rein to promote the device for everything" without liability.

"That's clearly at odds with the intent of the law," he said.

Infuse marketing has been the subject of at least seven government investigations since the product's introduction in 2002. A 2012 Senate Finance Committee study showed that Medtronic had paid $210 million from 1996-2010 to doctors to research Infuse. A review of 13 of those studies showed that they understated Infuse's potential dangers.

Since 2012, the FDA has been receiving reports of patient injuries related to Infuse at rates of more than 100 a month. An FDA study found virtually all Infuse injury complaints from 2002-2011 came from patients who received Infuse in ways the government never tested or approved.

Caplinger and her lawyers had hoped the justices would see "the clear contradiction" in saying that the FDA had jurisdiction over medical device uses that the agency neither tested nor monitored.

The court's decision not to do so, said Zieve, means that patients injured by non-FDA-approved uses of Infuse or other medical devices now face a much more difficult time finding lawyers to take their cases. Meanwhile, she predicted, Medtronic will likely be able to settle outstanding suits for very little money.

The company announced in a December 2015 filing with the Securities and Exchange Commission that it had reached tentative settlements in about 3,900 of the cases.

Zieve says that for permanently disabled patients like Caplinger who have undergone multiple surgeries and continue to live in agony, the settlement offer is nowhere near enough. "Her pain and suffering is ongoing," Zieve said. "For Medtronic, it's nothing. It's a cost of doing business for them."

Jim Spencer • 202-382-6123

Joe Carlson • 612-673-4779