Bone morphogenetic proteins (BMPs) have been widely used in spinal fusion surgeries since their approval in 2002, a new study published in the journal Spine says BMP use has declined in response to concerns about safety and complications.
After BMP received Food and Drug Administration (FDA) approval, its use in fusion surgery increased rapidly until 2008, involving up to 45.2 percent of lumbar and 13.5 percent of cervical fusions. But by 2008, serious safety issues had emerged. Questions about the safety of BMP in cervical fusions—a use for which InFuse had not been approved—prompted the FDA to issue a Public Health Notification that July.The new study evaluates the impact of these concerns on BMP use in elective spine surgery. The research team tested whether there was a statistically significant reduction in the rates of BMP use after the FDA notification. For lumbar fusion, the authors say, there was “an average annual increase of 7.9 percentage points per year from 2002 to 2008, followed by an average annual decrease of 11.7 percentage points thereafter. Similarly, BMP use in cervical fusion increased 2.0 percentage points per year until the FDA Public Health Notification, followed by an average decrease of 2.8 percentage point per year.”
The authors also cite evidence that the trials that led to BMP’s approval have design flaws and were done under industry influence. In 2012, an investigation by the U.S. Senate Finance Committee concluded, “Medtronic was 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.” The editorial board of the Annals of Internal Medicine reported, “Early journal publications misrepresented the effectiveness and harms through selective reporting, duplicate publication, and underreporting.” The North American Spine Society now recommends BMP only for anterior lumbar fusions.
InFuse is used instead of grafting bone harvested from the patient’s own hip, which can be more painful and usually requires longer recovery time. Early reports in medical journals claimed superior results for InFuse surgery, with little risk, but by 2008, the FDA had received reports of life-threatening complications, including bone and nerve injury, male infertility, infection, urinary problems, and cancer, according to Reuters. In 2011, Spine dedicated an entire issue to critiques of Medtronic-funded InFuse research, concluding that Medtronic had overstated the benefits and downplayed the risks of InFuse, according to Reuters.
FDA-approved studies often occur in ideal settings, with highly skilled surgeons, carefully selected patients, and strict adherence to protocols, the authors explain. But once a device is approved, it may “diffuse into widespread clinical practice,” used by surgeons with varying experience, and perhaps in less carefully selected patients, and patients therefore may be exposed to unnecessary risks.
Numerous patients have filed patients over injuries and complications, including catastrophic, unchecked bone growth after off-label InFuse surgery.