"It's no wonder the public has lost confidence in the drug and device industries."
Krumholz is overseeing Yale's review of Infuse. Those results are expected in January.
Medtronic's behavior also drew sharp criticism from two key senators on the committee.
"Medtronic's actions violate the trust patients have in their medical care," Sen. Max Baucus, (D-Mont.), chairman of the committee, said in a statement. "Patients everywhere will be better served by a more open, honest system without this kind of collusion."
Senior member Chuck Grassley (R-Iowa) said the findings support the Physician Payments Sunshine Act that he and Sen. Herb Kohl (D-Wis.) authored. That legislation will require drug and device companies to disclose such payments beginning next year.
"The findings also should prompt medical journals to take a very proactive approach...," Grassley said in a statement. "...The public will benefit from more transparency and accountability on their part."
In response to the Senate investigation, Medtronic turned over more than 5,000 documents, including emails involving the doctors and Medtronic employees as well as 14 years of payments from Medtronic to the doctors.
The Infuse Story
In January 2002, Dr. Hal Mathews spoke glowingly about Infuse to a FDA advisory panel that was considering whether to recommend approval of the product.
Mathews, then a Richmond, Va. spine surgeon who had taken part in the pivotal Infuse clinical trial, told the panel he had no direct financial interest in the product and that he was not being paid to appear at the meeting.
However, a 2001 email shows that Medtronic worked with the New York-based public relations firm, Ketchum, to prepare Mathews' speech to the panel, which went on to recommend approval of the product.
In addition, though Medtronic told the committee that Mathews was not paid for any activity undertaken in January 2002, Mathews was paid under consulting arrangements with the company in 2001.
In 2007, Mathews was hired by Medtronic as its vice president of medical and clinical affairs.
From the Pen of Medtronic
An email indicated that a Medtronic marketing employee, Julie Bearcroft, was involved in editing a 2005 Journal of Bone and Joint Surgery article and recommended against publishing a complete list complications related to the structural integrity of the fused area.
Those complications -- known as implant migration, subsidence and end-plate fracture -- had been observed in a clinical trial and had been formatted in a detailed table, according to an internal Medtronic email. But, following the advice of Bearcroft, that table was not included in the published paper.
"I personally think it is appropriate to simply report the adverse events were equivalent in the two groups without the detail," Bearcroft wrote in a note on a draft of the article.
After the editing change was made, the lead author of the paper, Dr. Ken Burkus, a Columbus, Ga. surgeon, sent a draft of the paper to his co-authors with the note, "this manuscript documents the superiority in clinical and radiographic outcomes with (Infuse)..."
Burkus, who got $6.4 million from Medtronic between 1998 through 2010, did not respond to an email seeking his comment.
Medtronic officials inserted into papers language that attempted to portray Infuse as a better, less painful alternative to the standard technique of using a small amount of a patient's own hip bone for fusing vertebrae, a claim that has been questioned by independent spine surgeons.