Comparative Clinical Effectiveness and Safety of Bone Morphogenetic Protein Versus Autologous Iliac Crest Bone Graft in Lumbar Fusion: A Meta-analysis and Systematic Review

STUDY DESIGN. This is a systematic literature review and meta-analysis. OBJECTIVE. We aimed to evaluate the efficacy and safety of recombinant human bone morphogenetic protein (RhBMP) and autologous iliac crest bone graft (ICBG) in lumbar fusion. SUMMARY OF BACKGROUND DATA. RhBMP has been emphasized in lumbar fusion due to high fusion success rate. However, ICBG remains the criterion standard graft approach for lumbar fusion. The safety and effectiveness of rhBMP are controversial. METHODS. Prospective randomized controlled trials were searched from PubMed, EMBASE, and Cochrane Central Register of Controlled Trails by using Medical Subject Headings terms “bone morphogenetic protein," “bone transplantation," and “spinal fusion." Two independent investigators screened eligible studies, assessed the bias of original articles, extracted data including fusion success, Oswestry disability index improvement, improved short form 36 questionnaire scores, adverse events and re-operation, and a subgroup analysis. The GRADE approach was used to grade quality of evidence. RESULTS. Twenty randomized controlled trials (2185 patients) met the inclusion criteria. There were higher fusion success rate (odds ratio [OR] 3.79, 95% confidence interval [CI] 1.88–7.63, P = 0.0002), better improvement of Oswestry Disability Index (mean difference 1.54, 95% CI 0.18–2.89, P = 0.03), and lower re-operation rate (OR 0.59, 95% CI 0.43–0.80, P = 0.0007) in rhBMP group. Heterogeneity was obvious in fusion success rate (I(2) = 58%); hence, a subgroup analysis, based on protein type (rhBMP-2 or rhBMP-7), was performed, which suggested that only rhBMP-2 was better than ICBG for lumbar fusion. There was no difference in the incidence of adverse events between rhBMP and ICBG (OR 0.91, 95% CI 0.70–1.18, P = 0.47). CONCLUSION. In lumbar fusion, rhBMP-2 exhibited a higher fusion success rate and reduced the risk of re-operation. No difference in complication rate is between rhBMP (rhBMP-2 and rhBMP-7) and ICBG. We suggest rhBMP especially rhBMP-2 as an effective substitute for ICBG for lumbar fusion. Level of Evidence: 1