Trends in the Use of Bone Morphogenetic Protein as a Substitute to Autologous Iliac Crest Bone Grafting for Spinal Fusion Procedures in the United States

Study Design. Analysis of Nationwide Inpatient Sample (NIS) database for data related to spinal fusion procedures. Objective. To identify trends in the use of bone morphogenetic protein (BMP) versus iliac crest bone grafts in various spinal fusion procedures performed in the United States, explore stratification by patient demographics, and analyze the impact on treatment cost. Summary of Background Data. BMP has been shown to achieve better clinical outcomes in anterior lumbar interbody fusions procedures, which led to its Food and Drug Administration approval for this indication in 2002. Since then, significant off-label use has occurred, without a full description of the results. Methods. We searched the NIS for data relating to BMP administration or iliac crest bone grafting in a variety of spinal fusion procedures performed from 1993 to 2006, based on International Classification of Diseases, Ninth Revision classification. The NIS is the largest all-payer inpatient care database, with demographic, outcome, and cost data from approximately eight million annual patient discharges throughout the United States. Demographics among patients treated with BMP versus iliac crest bone graft were compared to reduce the likelihood of bias in the analysis. Results. BMP became applied more frequently in each type of spinal fusion procedure examined over our study period, with the exception of anterior lumbar interbody fusions. Patients receiving iliac crest bone grafts versus BMP exhibited very similar demographic characteristics, including age, socioeconomic status, and type of health care setting. Although BMP typically increased the cost of the procedure itself, it improved outcomes and shorter hospital stays often provided a net benefit. Conclusion. BMP is increasingly being used in spinal fusion procedures, including ones for which it is not officially approved, because of the surgical and postsurgical benefits it provides. Given the morbidity that this may entail, monitoring outcomes trends will help to inform guidelines for BMP use and ensure that its benefits continue to outweigh its costs.