Agent often used in spinal fusion surgery associated with higher rate of cervical spine complications and higher fees

A genetically engineered biological agent used to promote bone formation is associated with a higher rate of complications in cervical spine (neck) fusions and greater hospital charges for all categories of spinal fusions, according to a study by researchers at Yale School of Public Health and Brigham and Women’s Hospital in Boston.

The study appears in the June 30 issue of Journal of the American Medical Association.

Clinical use of bone-morphogenetic protein (BMP) was approved by the US Food and Drug Administration in 2002 to promote bone fusion in surgery of the anterior lumbar spine, but has gained popularity for use in fusions at other spinal locations.

"Back pain is one of the most common reasons that patients seek care by a physician, and BMP is now estimated to be used in up to 25 percent of all spinal fusion surgeries in the United States," said senior author Elizabeth B. Claus, MD, PhD, a professor of biostatistics at the Yale School of Public Health and a neurosurgeon at Brigham and Women’s Hospital.

The researchers compared immediate postoperative, in-hospital rates of complications among patients undergoing spinal fusion surgeries with BMP in 2006, and found no differences for lumbar, thoracic, or posterior cervical procedures. But the use of BMP in anterior cervical (neck) fusion procedures was associated with a higher rate of complications – roughly 7 percent with BMP versus 4.5 percent without BMP. The greatest increases were in wound-related complications and in patients with difficulty in swallowing or hoarseness.

BMP use was also associated with greater in-patient hospital charges across all categories of fusion. Between 11 percent and 41 percent higher total hospital charges were reported, with the greatest percentage increase seen for anterior cervical fusion procedures.

"These findings point to the need to further study the long-term risks and benefits of BMP use so that clinical guidelines may be developed," Claus said.

The research was funded by the Brain Science Foundation. The paper was co-authored by Kevin Cahill, MD, PhD, John H. Chi, MD, MPH, and Arthur Day, MD, of the Neurosurgery Department at Brigham and Women’s Hospital.

(Source: Yale University: Journal of the American Medical Association: July 2009)