Benefits of Medtronic Infuse Bone Graft Misrepresented in Earlier Studies: Report

Washington, DCMedtronic bone graft has been hit with a significant setback with the publication of an extensive scientific review calling into question the integrity and validity of previous studies. While advocates applaud Medtronic for the transparency required to facilitate this review in the first place, the results nonetheless underscore the lengths medical device manufacturers will often take to support a product and place it in the best light possible.

According to the St. Paul Pioneer Press (6/16/13), things began to unravel for the then six-year-old Medtronic Infuse bone graft system when the US Food and Drug Administration (FDA) issued a warning against off-label use of Infuse, a process that uses the genetically engineered protein recombinant human Bone Morphogenetic Protein (rhBMP) to promote bone growth without the need to graft a patient’s own bone. The FDA’s concern centered on a specific set of indications where Infuse was approved for use. Medtronic off-label use, over which a surgeon has authority to circumvent the FDA’s mandated limitations, was generating concern. A whistleblower Medtronic lawsuit was also unsealed at about the same time as the FDA warning five years ago, further adding to the concern.

Three years later, in 2011, the publication Spine Journal suggested physicians paid by Medtronic had shown bias in research publications by understating the risks. That allegation was deepened further with the release of a US Senate report in 2012 alleging Medtronic influenced scientific articles through the payment of $210 million to various physicians who agreed to conduct research allegedly skewed to favor Medtronic bone.

To Medtronic’s credit, in the midst of such allegations, the medical device manufacturer provided $2.5 million to a group of researchers at Yale University and provided unparalleled access and transparency. “The bigger thing about [the report] is that a company has voluntarily released all their data, and a scientific debate can ensue,” said Dr. Harlan Krumholz, a Yale University physician who led the study.

However, the results appear to verify original suspicions that previously published research articles were, as originally alleged, misleading. One critic referred to them as “infomercials.”

The review found evidence of bias in previously published research studies where physicians and researchers “apparently” misrepresented the effectiveness of Medtronic bone.

In spite of Medtronic’s new-found transparency and access, the editors of Annals of Internal Medicine, which published the findings, were harsh.

“Early journal publications misrepresented the effectiveness and harms through selective reporting, duplicate publication and underreporting.

“After systematic evaluation and synthesis of all available evidence, both systematic reviews published here independently conclude that (Infuse) compared with iliac crest bone grafting, does not improve pain or function and increases adverse events, possibly including cancer,” the editors wrote.

Researchers from Oregon Health & Science University, who were hired to review Infuse data, also waded into the fray.

“Based on our analysis, it is difficult for us to find a clear indication to use (Infuse) for spinal fusion surgeries,” the Oregon researchers wrote. “Our analysis underscores that more definitive evidence about harms was needed before [Infuse] became widely used.”

Medtronic countered by reiterating their view that Medtronic bone graft is safe and effective, with outcomes comparable to that of using bone graft material in fusion surgery. Medtronic also pointed to an accompanying editorial authored by two spine surgeons that suggested use of Medtronic Infuse bone graft “seems clinically reasonable.”

But not everyone shares that view. Dr. Eugene Carragee, editor of Spine Journal and also a prominent Stanford University surgeon, pulled no punches in his criticism.

“A surgeon would need a truly exceptional case to use [Infuse] when the data for its use are marginal, and even what we have comes through potentially biased filters at every level,” Carragee said in a statement. “Unless we remain vigilant, medical publications will continue to devolve into information-laundering machines and clinical studies will become infomercials for their corporate sponsors.”

The study also noted Medtronic complications that included possible cancer risk associated with use of Medtronic bone, but researchers urged caution when interpreting that finding.