Safety and Effectiveness of Recombinant Human Bone Morphogenetic Protein-2 for Spinal Fusion A Meta-analysis of Individual-Participant Data

Background: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is widely used to promote fusion in spinal surgery, but its safety has been questioned. Purpose: To evaluate the effectiveness and safety of rhBMP-2. Data Sources: Individual-participant data obtained from the sponsor or investigators and data extracted from study publications identified by systematic bibliographic searches through June 2012. Study Selection: Randomized, controlled trials of rhBMP-2 versus iliac crest bone graft (ICBG) in spinal fusion surgery for degenerative disc disease and related conditions and observational studies in similar populations for investigation of adverse events. Data Extraction: Individual-participant data from 11 eligible of 17 provided trials sponsored by Medtronic (Minneapolis, Minnesota) (n = 1302) and 1 of 2 other eligible trials (n = 106) were included. Additional aggregate adverse event data were extracted from 35 published observational studies. Data Synthesis: Primary outcomes were pain (assessed with the Oswestry Disability Index [ODI] or Short Form-36), fusion, and adverse events. At 24 months, ODI scores were 3.5% lower (better) with rhBMP-2 than with ICBG (95% CI, 0.5% to 6.5%) and radiographic fusion was 12% higher (CI, 2% to 23%). At or shortly after surgery, pain was more common with rhBMP-2 (odds ratio, 1.78 [CI, 1.06 to 2.95]). Cancer was more common after rhBMP-2 (relative risk, 1.98 [CI, 0.86 to 4.54]), but the small number of events precluded definite conclusions. Limitation: The observational studies were diverse and at risk of bias. Conclusion: At 24 months, rhBMP-2 increases fusion rates, reduces pain by a clinically insignificant amount, and increases early postsurgical pain compared with ICBG. Evidence of increased cancer incidence is inconclusive.