Senate Launches Investigation of Medtronic Spine Fusion Device

June 22, 2011— -- A U.S. Senate committee has launched an investigation into reports that doctors with financial ties to the medical device company Medtronic were aware of potentially serious complications with a spine surgery product made by the company yet failed to reveal those problems in published journal articles.

Citing news articles based on a Journal Sentinel/MedPage Today investigation, two powerful members of the Senate Finance Committee contacted Medtronic Tuesday demanding an extensive list of documents, including financial records and communications between the company and doctors who have received millions in royalties and other payments from Medtronic over the last decade.

Medtronic was warned not to destroy or make inaccessible any of the documents, data or other related information in the letter signed by committee chairman Max Baucus (D-Mont.) and senior member Chuck Grassley (R-Iowa).

The growing controversy involves Medtronic's spine surgery product Infuse, which was approved by the Food and Drug Administration in 2002.

Over the last year, an ongoing series of Journal Sentinel/MedPage Today investigations has raised questions about annual payments made to a core of prominent surgeons around the country who were involved either in the clinical testing of Infuse or co-authoring positive medical journal articles that failed to link the product to serious complications.

"We are extremely troubled by press reports suggesting that doctors conducting clinical trials examining the safety and effectiveness of Infuse on behalf of Medtronic were aware that Infuse, a treatment commonly used in spinal surgery, may cause medical complications, but failed to report this in the medical literature," Baucus and Grassley wrote. "This issue is compounded by the fact that some clinical investigators have substantial financial ties to Medtronic."

The letter was addressed to Omar Ishrak, who took over this month as chairman and chief executive of Minneapolis-based Medtronic.

Infuse, also known as bone morphogenetic protein-2, is a powerful biological agent used in spinal fusion surgery. The product stimulates bone growth and eliminates the need to harvest a small amount of a patient's own bone to create a fusion between two vertebrae. As a result, it is highly popular with spine surgeons.

Medtronic says Infuse has been implanted into more than 500,000 patients and it is used by more than 2,300 surgeons. Its sales amount to several hundred million dollars a year.

However, the product has been dogged by reports of financial conflicts of interest by researchers; serious—unreported—complications; and extensive off-label use. Moreover, evidence has accumulated suggesting that the superior clinical results reported by doctors with financial ties to Medtronic have not been replicated when the device was used by doctors with receive no payments from Medtronic.

Medtronic also has been under investigation by the U.S. Department of Justice on allegations of off-label marketing of Infuse. About 85% of Infuse use is off-label.

Sohail Mirza, MD, a professor of orthopedics at Dartmouth Medical School, said he was pleased that the Finance Committee was investigating the matter.