Bone Morphogenetic Proteins Use Has Declined. In the last 12 years, bone morphogenetic proteins (BMPs) have been used in spinal fusion procedures, but the authors of a study published in Spine say BMP use has declined in response to concerns about safety and complications.
After approval by the Food and Drug Administration (FDA) in 2002, use of BMP with fusion increased rapidly until 2008, involving up to 45.2 percent of lumbar and 13.5 percent of cervical fusions. But by 2008, issues of safety and complications had emerged. Concerns about the safety of BMP in cervical fusions—for which InFuse was not approved—prompted the FDA to issue a Public Health Notification in July 2008. Questions about safety and off-label use of BMP led professional societies to make recommendations about the appropriate use of BMP in spinal fusion.
The authors undertook their study in order to evaluate the impact of these concerns on BMP use in elective spine surgery. They 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.”
BMP Have Design Flaws
The authors of the Spinearticle say there is evidence that the trials that led to FDA approval of BMP have design flaws and were done under industry influence. In 2012, the U.S. Senate Finance Committee concluded that “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 patients undergoing anterior lumbar fusions.
InFuse is used instead of a graft of bone harvested from the patient’s own hip, which can be more painful and usually requires longer healing 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.
Numerous lawsuits have been filed by patients who have suffered injuries and complications, including catastrophic, unchecked bone growth after InFuse surgery.
The study’s authors explain that FDA-approved studies often occur in ideal settings, with highly skilled surgeons, carefully selected patients, and strict adherence to protocols, but, once approved, devices may “diffuse into widespread clinical practice,” used by surgeons with varying experience, and perhaps in less rigorously selected patients. The safety profile may therefore be worse than in FDA Safety and Effectiveness reports, and this may expose patients to unnecessary harms and preventable complications.