Summary: Although the FDA has approved rhBMP 2 for use in anterior spinal fusion since 1990, there has not been approval for alternative locations. Many surgeons, however, use rhBMP 2 in an off label manner. This survey of adult spinal deformity surgeons determined that amount, location and use of BMP varied significantly amongst spinal surgeons. Additionally, significant complications were associated with BMP use including persistent drainage and radiculitis.
Introduction: rhBMP 2 (InFuse) was approved for anterior interbody fusion in an LT cage in 1990. Since that time, it has been used in increasing numbers by spinal deformity surgeons, in off label applications. Some authors have reported improved fusion rates, however there are associated risks. These include increased cost and complications. There are no Level 1 studies to guide surgeons in the use, location and amount of BMP in spinal deformity surgery. The purpose of this study is to survey the use of BMP amongst spinal deformity surgeons across the country.
Methods: 14 surgeons, specializing in adult spinal deformity, were surveyed to determine the indications, complications, location and amount of BMP used for deformity spinal fusions. The results were tallied and statistical analysis was performed.
Results: The indications for using rhBMP 2 in spinal fusion varied widely among the surgeons surveyed. The most important factors that led to BMP use were revision surgery, levels to be fused, and smoking history. The most frequent complications that were attributed to BMP use were increased post‐operative drainage (8/14 surgeons) and radiculitis (10/14 surgeons). Anterior BMP (within a cage or femoral ring) was used commonly (11/14 responders), most often for multilevel anterior lumbar interbody fusion. The amount of BMP used anteriorly varied from 3 to 6 mg/level. 10/14 used BMP routinely for posterior multilevel fusions with the amount varying from 0.85 mg/level to 3.4 mg/level. Revision posterior surgery had the highest use overall, with 12/14 surgeons using BMP routinely. The amount of BMP used for posterior multilevel revision surgery varied from 0.85 mg/level to 4.29 mg/level.
Conclusion: Off label use of BMP has become prevalent among spinal deformity surgeons in an effort to enhance fusion rates and improve surgical outcomes in spinal deformity patients. However, there was a wide variation in the indications, amount and location of BMP used. BMP use is not benign and there is an increasing recognition of potential complications. The appropriate indications and dosage of BMP in spinal deformity patients remains unknown.
The FDA has not cleared the drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an ‘off label’ use).