Bone morphogenetic protein vs. autologous iliac crest bone graft in lumbar fusion surgery
A meta analysis of lumbar spinal fusion surgery using bone morphogenetic proteins and autologous iliac crest bone graftPLoS One. 2014 Jun 2;9(6):e97049. doi: 10.1371/journal.pone.0097049. eCollection 2014.
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19 randomized controlled trials (n=1852) were included in this meta-analysis comparing bone morphogenetic protein (BMP) to autogenous iliac crest bone graft (ICBG) in lumbar fusion for patients with lumbar degenerative disease. Results demonstrated a significantly higher fusion rate, significantly lower reoperation rate, and a significantly shorter operation time favouring BMP over ICBG. Hospital stay was borderline significant in favour of BMP, while clinical success, complication rate, blood loss, patient satisfaction, work status, return to work were not significantly different between patient cohorts.
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Was the validity of all of the studies referred to in the text assessed with use of appropriate criteria (either in selecting the studies for inclusion or in analyzing the studies that were cited)?
Were the methods used to combine the findings of the relevant studies (to reach a conclusion) reported?
Were the findings of the relevant studies combined appropriately relative to the primary question that the overview addresses?
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Detsky AS, Naylor CD, O'Rourke K, McGeer AJ, L'Abbé KA. J Clin Epidemiol. 1992;45:255-65
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Why was this study needed now?
In lumbar fusion surgery, autogenous iliac crest bone (ICBG) is primarily used as a graft. Nonetheless, well-documented complications have included morbidity of the donor site and a high incidence of nonunion. In light of this, bone morphogenetic proteins (BMPs) have been developed as an alternative. Large scale production was achieved following advancements in gene sequencing and recombinant techniques. Both rhBMP-2 and rhBMP-7 have been approved by the FDA. This meta-analysis was needed to evaluate the comparative efficacy of BMPs to ICBG in spinal fusion surgery.
What was the principal research question?
How does the safety and efficacy of bone morphogenetic proteins compare to autogenous iliac crest bone grafts in lumbar fusion surgery?
What were the important findings?
- Fusion rate was reported in 17 studies (BMP: n=610, ICBG: n=523). Pooled analysis indicated a significant difference, in favour of BMP over ICBG, although with moderate heterogeneity (RR: 1.13 [95% CI 1.05-1.23]; p=0.003; I^2=52%). Subgroup analysis of BMP-2 only demonstrated similar results (RR: 1.16 [95% CI 1.06–1.27]; P = 0.001; I^2=62%). The BMP-7 subgroup indicated contrasting results (RR: 0.90 [95% CI 0.69-1.17]; p=0.43; I^2=0%).
- Clinical success was assessed in 8 studies (BMP: n=431, ICBG: n=265). Pooling of data demonstrated no significant difference between groups (RR: 1.04 [95% CI 0.95-1.13]; p=0.38; I^2=2%).
- Complication rate was pooled from 9 studies (BMP: n=605, ICBG: n=444) and results indicated no significant between group difference (RR: 0.96 [95% CI 0.85-1.09]; p=0.54; I^2=0%).
- Reoperation rate from 14 studies were pooled for analysis (BMP:n=1004, ICBG: n=766). Results demonstrated a significantly lower rate for BMP over ICBG (RR: 0.57 [95% CI 0.42-0.77]; p=0.0002; I^2=0.66).
- Pooled results favoured BMP over ICBG significantly, with respect to operating time (RR: -0.32 [95% CI -0.55 to -0.08]; p=0.009; I^2=79%), and hospital stay (RR: -0.56 [95% CI -1.12 to -0.01]; p=0.05; I^2=70%), whereas comparable results were observed for blood loss (RR: -50.24 [95% CI -117.38 to 16.90]; p=0.14; I^2=77%).
- Patient satisfaction, work status, and return to work were not significantly different between groups (p=0.58, p=0.63, and p=0.68, respectively) when pooled.
What should I remember most?
Pooled analyses demonstrated significantly higher fusion rates, lower reoperation rates, and shorter operation times with bone morphogenetic protein (BMP) when compared to autogenous iliac crest bone graft. Additionally, difference in hospital stay was borderline significant in favour of BMP, whereas clinical success, complication rate, blood loss, patient satisfaction, work status, return to work were comparable between groups.
How will this affect the care of my patients?
The results suggest that bone morphogenetic protein increases fusion rate while reducing reoperation rates and operation times for lumbar fusion in patients with systematic lumbar degenerative disease. Clinical success and complication rates, however, were similar to those of the standard autogenous iliac crest bone grafting procedure. Additional high-quality randomized controlled trials are needed to determine the long-term effects of bone morphogenetic protein, and whether it is superior to autogenous iliac crest bone grafting.
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