Medical journal blasts Medtronic-sponsored studies of spine product

Medtronic headquarters
Medical device maker Medtronic is headquartered in Fridley, Minn. A medical journal says that studies of the company's product, Infuse, used to spur bone growth after spinal surgery, failed to disclose serious and potentially life-threatening side effects.
AP Photo/Jim Mone

Medtronic and some researchers who evaluated company spine products are getting blasted in a medical journal for allegedly biased research that didn't acknowledge serious side effects. The Spine Journal found the risk to patients from Medtronic's bone graft products was as much as 50 times greater than the original company-supported research suggested.

Dr. Eugene Carragee is a professor of orthopedic surgery at Stanford University and one of the doctors who reviewed 13 professional journal reports about Medtronic's spinal bone graft products. The review led to a scathing editorial published this month in The Spine Journal. Carragee said the Medtronic-sponsored studies were largely silent on important complications that subsequent, independent studies reported.

"The upshot is that most doctors were unaware of the extent of complications in these trials, based on the medical literature," Carragee said. The initially unreported complications can be very serious, Carragee said. "The risks of the product included significant back pain, significant leg pain events, neurological injury, sterility in men, an association with cancer, association with the bones dissolving where the drug had come in contact," he said. "These were serious complications to have patients and doctors understand."

At least some of the Medtronic-sponsored studies were flawed or structured to make Medtronic products look good, Carragee said.

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In addition, Carragee said Medtronic paid as much as $26 million to researchers whose studies did not report complications.

Medtronic officials declined to be recorded for broadcast, but released a statement in which CEO Omar Ishrak acknowledged the Spine Journal's questions about researchers' conclusions.

However, Ishrak said the journal did not raise questions about the data Medtronic submitted to the FDA for the agency's review of the products' safety and effectiveness or about the information in brochures attached to each product sold.

While Caragee is concerned about how Medtronic's bone graft products have been reviewed and used, he said they are still very good treatments for people who can't heal their own bones.

"Taking it off the market would be a bad idea," Caragree said.

Medtronic said it believes its spinal products are being used safely. The statement said Medtronic has been an industry leader toward eliminating or mitigating conflicts of interest, will further refine internal policies as warranted, and strive to lead the industry in ethical and transparent business practices.

Last week, two U.S. Senators asked Medtronic to address concerns about the safety of its spinal bone graft product, as well as financial ties between the company and clinical investigators who reviewed the device.

The U.S. Department of Justice has also inquired about Medtronic's bone graft products.

Despite a recent string of bad publicity for those products, investors may shrug. Dave Heupel, portfolio manager for Thrivent Financial for Lutherans, doubts the bone graft concerns will further damage Medtronic's already stagnating finances.

"Expectations for it, sales have certainly been in decline," he said. "It's still a reasonably-sized product. But I don't think there were any grandiose plans that the resurgence of Medtronic was going to come on the heels or backbone of InFuse."

Sales of InFuse suffered after regulators warned the product has been linked to some life-threatening complications.

But the product is not a make-or-break item for Medtronic. Analysts estimate InFuse sales amount to less than 10 percent of the company's total revenue of about $16 billion a year.