Research in the Journal of Pediatric Orthopaedics shows that bone morphogenetic protein (BMP) in pediatric spinal fusion surgery does not improve surgery outcomes and should be used with caution.
The study focused on pediatric spinal fusion patients in New York State from 2004 to 2014. Researchers used a large database to identify the pediatric spinal fusions that occurred in the state during that time.
Of 7,312 children and adolescents who had spinal fusion during the study period, 462—or 6.7 percent—received BMP.
The study authors also found a racial and socioeconomic connection to BMP usage. BMP was more likely to be used in pediatric patients who were older, white, and had higher family income.
Researchers found no difference in surgery success rates in patients who had BMP versus those who did not, though BMP was associated with a significantly higher risk for spinal instrumentation complication at 5 years after surgery.
What Is Bone Morphogenetic Protein (BMP)?
BMP is a protein used to promote new bone growth and stimulate the fusion process during spinal fusion surgery. Human bone contains small amounts of BMP, but genetic engineering can produce the substance greater quantities.
One of the reasons spine surgeons use BMP is to help prevent failed fusion—when the affected vertebrae do not fuse together into a single bone. Children don’t have as great of risk of failed fusion as adults, so the study authors question the need to use BMP.
“Use of BMP in pediatric patients is controversial,” wrote the study authors. “Although in adult spine arthrodesis [fusion], the nonunion rate is as high as 10% to 15%, in children, nonunion after spinal arthrodesis [fusion] is a much less common complication.”
BMP is not approved by the U.S. Food and Drug Administration (FDA) for use in pediatric spinal fusion. And, when BMP is used in pediatric spinal surgery, it’s use is considered off-label.
What Does Off-Label Mean?
Using products “off-label” means a product, medication, or device is used outside the FDA indication, says SpineUniverse Editorial Board member Jeffrey C. Wang, MD, Professor of Orthopaedic Surgery and Neurosurgery at USC Spine Center in Los Angeles, who shared his comments on this study.
“In medicine, there are often other uses for a product that doctors may find beneficial to their patients, but it is for reasons ‘outside’ the FDA labeled indications,” Wang says. “For example, aspirin was initially used as a pain reliever, but further studies showed it may help prevent heart attacks or strokes. Sometimes, evidence shows a benefit to the use of a medicine, even though it was not formally approved by the FDA.”
In relation to this study, Dr. Wang notes that BMP was FDA approved only for anterior lumbar interbody fusion within a specific type of anterior lumbar cage.
“However, BMP has shown powerful bone formation, which may have benefit for spinal fusions in other areas,” Dr. Wang says. “When used in other areas, although it can result in a reliable healing of the fusion, it is technically being used outside the FDA approved indication.”
You can read more about BMP in BMPs and Biologic Materials in Spine Surgery.
What You Can Take Away from the Study
Since the introduction of BMP, it has been increasingly used to support successful fusion in spinal fusion surgery, primarily in adult cases. But, BMP’s risks and benefits for children are not as understood—and its use in pediatric spine surgery is controversial.
While this study found a spike in BMP use in children’s cases, the authors suggest a downward trend in BMP’s use for young patients, driven by safety concerns over off-label use of BMP for pediatric patients.
While this study focused exclusively on patients in New York State, Dr. Wang says it may be applicable to patients in other states or reflective of a larger nationwide trend. But, given that this is only one study with a state-specific population, more research is needed to truly understand BMP’s effect on pediatric patients on a larger scale.
“This is a very controversial topic, so further study on the potential complications is warranted,” Dr. Wang says.