Study finds increase in bone morphogenetic protein usage for Off-Label procedures

Sep 8 2010

Bone morphogenetic protein (BMP) is increasingly used as an alternative to the patient's own bone for spinal fusion surgery. Yet at least 85 percent of these procedures are operations for which BMP use has not been formally approved by the U.S. Food and Drug Administration (FDA), suggests a study in the September 1 issue of Spine. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals, and institutions in medicine, nursing, allied health, and pharmacy.

Although BMP is approved for use in stimulating bone growth in one specific type of spinal fusion surgery, it is more often used for non-approved, "off-label" purposes, according to the new study, led by Kevin L. Ong, PhD, of Exponent, Menlo Park, Calif. Dr Ong and coauthors write, "With uncertainty regarding the risks of using BMP in certain off-label applications, further research will be needed to better define the appropriate indications."

Use of BMP for Spine Surgery Is Rising Rapidly…
The researchers used a large U.S. hospital database to analyze trends in the use of BMP for spinal surgery. Bone morphogenetic proteins are growth factors that can induce the formation of new bone. They provide an alternative to using the patient's own bone—typically from the hip bone (iliac crest)—as a source of grafts for spinal fusion procedures.

From 2002 to 2007, BMP was used in approximately 340,000 surgical procedures. During this time, the use of BMPs more than quadrupled—from about 24,000 to 103,000 procedures. More than 90 percent of these operations were spinal fusion procedures. (BMP is also used in some less-common operations, such as surgery for complex fractures.)

The FDA has formally approved BMP for use in only one type of spinal fusion procedure—a lower back operation called anterior lumbar interbody fusion (ALIF). However, ALIF procedures accounted for only about 17 percent of procedures using BMP in the study.

But Mostly for 'Off-Label' Procedures
In contrast, BMP was more often used for other spinal fusion procedures for which it has not received formal FDA approval. These included operations on the upper (thoracic and cervical) spine and fusion of the back of the spine (posterior) rather than the front of the spine (anterior). "At least 85 percent of principal procedures using BMP were for off-label applications," according to the authors.

The data also showed significant variations in the use of BMP. Procedures with BMP were more likely for women than men and in middle-aged patients (45 to 64 years) than in older adults. Use of BMP also varied by region—it was most frequently used in the South and least frequently in the Northeast.

The results confirm that BMP use for spinal fusion surgery has increased dramatically in recent years, but show most of the increase has been in off-label procedures not specifically approved by the FDA. It is not unusual for new medical products to be used for such off-label purposes, and some studies have supported the use of BMP for spinal operations other than ALIF. However, there are still some safety concerns associated with these uses of BMP, including the risk of some potentially serious complications.

The variations in BMP use by sex, age, and region highlight the need for further study to identify the most appropriate situations for the use of BMP, Dr. Ong and colleagues believe. Meanwhile, an FDA advisory panel is scheduled to consider the benefits and risks of BMP—including both approved and off-label uses—at a meeting later this month.

Source: Lippincott Williams & Wilkins