Medtronic Infuse Effectiveness, Safety, Questioned By New Studies

Two new studies suggest that Medtronic’s controversial Infuse bone growth product provides no benefits over traditional spine surgery, and may expose users to certain side effects, including a potential risk of cancer.  

The two independent reviews, published in the Annals of Internal Medicine on Monday, provide an independent review of data involving all clinical trials conducted involving Medtronic’s Infuse.

The reviews come following controversy that made it all the way to the U.S. Senate, after it was discovered that Medtronic influenced prior studies involving the Infuse bone graft to hide complication rates and potential side effects.

Medtronic Infuse is a bone morphogenetic protein (BMP) that is designed to be applied to an absorbable collagen sponge placed within a device known as an LT-Cage, which is then implanted to encourage bone growth and fuse the gaps between vertebrae. It is promoted as an alternative to traditional spinal surgery, where bone is harvested from another part of the body or a cadaver, to encourage fusion of the vertebrae.

Although the FDA only approved the Medtronic Infuse for limited applications involving the use of an LT-Cage during a single-level anterior lumbar interbody fusion (ALIF), where the spine is approached from the front, the Medtronic Infuse has been widely used “off-label” for other types of spine fusion surgery, and it has been linked to reports of severe and painful complications caused by excessive or ectopic bone growth following use beyond what was approved as safe and effective by the FDA.

A number of Medtronic Infuse lawsuits have now been brought nationwide by individuals who experienced side effects following the off-label use of the device.

The findings of this independent review have been highly anticipated, given Medtronic’s prior influence over data involving the Infuse bone graft’s effectiveness and safety.

Independent Review of Medtronic Infuse Safety Data

All of Medtronic’s patient-level data gathered during the Infuse clinical trials was made available through the Yale University Open Data Access (YODA) Project. Publishing two systematic reviews of this scale at the same time is a first for the Annals of Internal Medicine, according to an editorial that accompanied the studies.

One of the Medtronic Infuse studies was conducted by researchers from Oregon Health & Science University. The other study was conducted by researchers from the University of York in the U.K.

The findings of both suggested that the outcome of spinal surgery conducted with Infuse was no better than the outcomes of traditional spine surgery. Researchers from Oregon also found an increase in cancer risk among Infuse patients in the two years following surgery. The University of York study did not detect the same cancer risk.

Researchers indicated that it was hard to find a good reason to actually use Medtronic Infuse, and they also found significant reporting bias in previous studies by Medtronic, which overstated the benefits of the bone growth product.

“Our study shows that adverse events were underreported for more on- and off-label uses, with results not previously available to the public,” Oregon Health & Science University researchers concluded. “Journal practices for sponsored supplements, trial registration, and conflict of interest disclosure may have contributed to publication of an incomplete and sometimes misleading evidence base.”

Data Follows Scathing Congressional Report on Infuse Studies

In 2012, the U.S. Senate Finance Committee released a report detailing the findings of a congressional investigation into whether Medtronic had manipulated previous medical studies that appeared to downplay Infuse risks and overstate its effectiveness.

Congressional investigators found that Medtronic paid out $210 million to authors of studies sponsored by the company. Those studies appeared to have purposefully left out findings that suggested Infuse could increase the risk of male sterility, bone growth problems, cancer, and back and leg pain.

The 16-month investigation found that Medtronic employees edited and even wrote parts of some of the studies before they were published. However, the studies did not disclose Medtronic employee involvement.

The report’s findings indicate that “Medtronic was heavily involved in drafting, editing, and shaping the content of medical journal articles authored by its physician consultants who received significant amounts of money through royalties and consulting fees from Medtronic.”

Investigators said when that wasn’t enough, Medtronic went even further, with company officials inserting language into scientific studies that suggested Infuse was a better, less painful technique than the autograft technique, which involves taking bone graft from the pelvic bone.

One email exchange revealed that Medtronic employees urged that a complete list of adverse events linked to Infuse not be published in a 2005 study.