rhBMP Use in Cervical Spine Surgery: Associated Factors and In-Hospital Complications

Background: Widespread use of recombinant human bone morphogenetic protein (rhBMP) in cervical spine surgery has continued despite the U.S. Food and Drug Administration's 2008 notification regarding its adverse effects. Our study goals were to analyze how patient, surgical, and institutional factors influenced rhBMP use in cervical spinal fusion surgery and to examine the cervical-spine-specific in-hospital complications associated with rhBMP use. Methods: The Nationwide Inpatient Sample database was used to identify 1,064,372 patients eighteen years or older who had undergone cervical spinal fusion surgery from 2003 through 2010. Of these patients, 84,726 (7.96%) received rhBMP. Multivariate logistic regression models were used to analyze patient, surgical, and institutional factors associated with rhBMP use, and the relationship between rhBMP Use and the development of in-hospital complications. Results: On multivariate analysis, patient age and sex, insurance type, surgical approach, use of autograft bone, and hospital teaching status, size, and region were significant predictors of rhBMP use. Use of rhBMP was a significant predictor of complications on univariate analysis and on multivariate analysis adjusted for patient age and sex, Charlson comorbidity score, insurance status, surgical approach, autograft bone use, and hospital teaching status, size, and region. Use of rhBMP was significantly associated with the development of dysphagia (prevalence, 2.0%; adjusted odds ratio [OR], 1.53), dysphonia (prevalence, 0.28%; adjusted OR, 1.48), hematoma/seroma formation (prevalence, 0.7%; adjusted OR, 1.24), and neurological complications (prevalence, 0.84%; adjusted OR, 2.0). These complications were most commonly found after anterior cervical fusion surgery. Wound infections and neurological complications were most commonly found after posterior cervical fusion surgery. Dysphagia was most commonly found after circumferential fusion surgery. Conclusions: Indications for rhBMP use for cervical spinal fusion are multifactorial. Its use is associated with a significantly higher likelihood of cervical-spine-specific complications.