Questions About Spine Fusion Product Prompt a New Process for Reviewing Data

Abstract

A C O N V E R G E N C E O F P E E Rreviewed research, press scrutiny, federal investigations, and serendipity may lead to a clearer understanding of the safety and efficacy of a spinal fusion product manufactured by Medtronic, Inc. At issue is Infuse Bone Graft, a product containing recombinant bone morphogenetic protein-2 (BMP-2), a synthetic bone growth factor that was approved in 2002 by the US Food and Drug Administration (FDA) for singlelevel anterior interbody lumbar fusion. The product has become widely adopted in spine surgery; by 2007, it was used in more than 50% of primary anterior lumbar spine fusions. Since then, the product’s use has expanded further, as positive efficacy and safety results for other indications (posterolateral lumbar fusion, posterior lumbar interbody fusion, and anterior cervical discectomy and fusion) from industrysponsored trials have been published in the peer-reviewed literature. But as the product’s use increased, so did skepticism. A news story published in August 2010 by the Milwaukee Journal Sentinel (http://t inyurl.com /4yfcn24) raised conflict-of-interest issues surrounding the FDA’s approval of BMP-2. The Journal Sentinel reported that at the FDA’s advisory committee meeting, a committee member noted a number of physicians whose research had been submitted to the agency had a financial stake in BMP-2 and that their results were more positive with respect to the device than were findings submitted from researchers who did not have a financial interest in the product. Some researchers were also becoming skeptical about the postmarketing studies that validated using BMP-2 off label. For example, researchers noted that industry-sponsored trials pub-