Bone morphogenetic protein-associated complications in pediatric spinal fusion in the early postoperative period: an analysis of 4658 patients and review of the literature

Abstract

Object: Use of recombinant human bone morphogenetic protein-2 has risen steadily since its approval by the FDA for use in anterior lumbar interbody fusion in 2002. The FDA has not approved the use of bone morphogenetic protein (BMP) in children. Age less than 18 years or lack of evidence of epiphyseal closure are considered by the manufacturer to be contraindications to BMP use. In light of this, the authors performed a query of the database of one of the nation's largest health insurance companies to determine the rate of BMP use and complications in pediatric patients undergoing spinal fusion.

Methods: The authors used the PearlDiver Technologies private payer database containing all records from United Health-Care from 2005 to 2011 to query all cases of pediatric spinal fusion with or without BMP use. A review of the literature was also performed to examine the complications associated with BMP use in pediatric spinal fusion.

Results: A total of 4658 patients underwent spinal fusion. The majority was female (65.4%), and the vast majority was age 10-19 years (94.98%) and underwent thoracolumbar fusion (93.13%). Bone morphogenetic protein was used in 1752 spinal fusions (37.61%). There was no difference in the rate of BMP use when comparing male and female patients or age 10 years or older versus less than 10 years. Anterior cervical fusions were significantly less likely to use BMP (7.3%). Complications occurred in 9.82% of patients treated with versus 9.88% of patients treated without BMP. The complication rate was nearly identical in male versus female patients and in patients older versus younger than 10 years. Comparison of systemic, wound-related, CNS, and other complications showed no difference between groups treated with and without BMP. The reoperation rate was also nearly identical.

Conclusions: Bone morphogenetic protein is used in a higher than expected percentage of pediatric spinal fusions. The rate of acute complications in these operations does not appear to be different in patients treated with versus those treated without BMP. Caution must be exercised in interpreting these data due to the many limitations of the administrative database as a data source, including the short length of follow-up.

Keywords: BMP = bone morphogenetic protein; ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification; KID = Kids' Inpatient Database; SRS M&M = Scoliosis Research Society Morbidity and Mortality; allograft; bone morphogenetic protein–2; bone morphogenetic protein–7; complications; pediatric; rhBMP-2 = recombinant human BMP–2; spine fusion.