Complications With Recombinant Human Bone Morphogenic Protein-2 in Posterolateral Spine Fusion

Abstract

Retrospective case series. The purpose of this study was to report on a large consecutive series of posterolateral fusion cases using rhBMP-2/ACS. Despite evidence that rhBMP-2/ACS is effective as an iliac crest graft substitute in posterolateral fusion, concerns remain regarding potential risk for BMP use in clinical practice. These concerns have been fueled by the serious complications reported with BMP in anterior cervical spine fusion. While none of the literature on posterolateral fusion with rhBMP-2/ACS has suggested an increased complication rate versus iliac crest bone graft, this issue has not been specifically studied. We reviewed medical records for a consecutive series of 1037 patients who underwent posterolateral spine fusion using rhBMP-2 between 2003 and 2006. Medical complications were attributed to the surgical procedure if they occurred within the 3-month perioperative period, whereas complications potentially related to BMP were included regardless of time frame. Medical and surgical complications were observed in 190 of 1037 patients (18.3%) with 81 major complications (7.8%) and 110 minor complications (10.2%). Neurologic complications were related to screw malposition in 6 patients and epidural hematoma in 3 patients. New or more severe postoperative radicular symptoms were noted in 7 patients (0.7%). Psoas hematoma was identified by CT scan in 8 patients (0.8%). Complications directly related to rhBMP-2 were observed in at least 1 patient (0.1%) and in a worst case analysis, in as many as 6 patients (0.6%). This study in 1037 patients confirms the relative safety of rhBMP-2/ACS for posterolateral spine fusion. There were extremely few complications directly attributed to rhBMP-2/ACS, and the overall complication rates were consistent with established norms. The stark contrast between this experience and the markedly elevated complication rate reported with anterior cervical BMP usage emphasizes the need to evaluate risks and benefits of bioactive technologies in a site-specific and procedure-specific manner.