Comparative analysis of autograft vs. synthetic bone graft in spinal fusion: a systematic review and meta-analysis.

BACKGROUND

Autografts are regarded as the gold standard for spinal fusion owing to their capability to promote bone formation. However, synthetic bone grafts are gaining popularity for their consistency and avoidance of donor site complications. This meta-analysis compares the treatment results of autografts and synthetic bone grafts in spinal fusion procedures and evaluates their clinical effectiveness.

METHODS

The study adhered to PRISMA guidelines and conducted a comprehensive literature search. It compared autografts and synthetic bone grafts in spinal fusion by employing a random-effects model for meta-analysis, assessing publication bias, and evaluating the certainty of evidence using Grading, Reporting, Assessment, Development, and Evaluation (GRADE) guidelines, along with methodological quality through the risk of bias-2.0 (RoB-2.0) and Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tools.

RESULTS

Following a thorough screening, nine studies fulfilled the inclusion criteria. In the subgroup analysis, the pooled effect size for the fusion rate between different types of synthetic bone graft [ceramics, i-Factor, demineralized bone matrix (DBM)] and compared with autograft was 1.24 odds ratio (OR) [95% confidence interval (CI): 0.77-2.02; P=0.38; I2=0%], success rate for ceramics, i-Factor, and bioactive glass was 1.78 OR (95% CI: 1.28-2.48; P=0.0006; I2=0%). The blood loss had an -0.88 standardized mean difference (SMD) (95% CI: -1.90 to 0.15; P=0.09; I2=87%). For reoperation, the effect size was 0.78 (95% CI: 0.37-1.68; P=0.53; I2=0%), and in the complications subgroup analysis (i-Factor, ceramic, bioactive glass), the pooled effect size was 0.82 (95% CI: 0.54-1.24; P=0.35; I2=0%). A funnel plot revealed publication bias, while most studies demonstrated minimal risk of bias. However, the certainty of evidence was low because of this bias and wide variance.

CONCLUSIONS

Synthetic bone grafts can be a reliable alternative to autografts in spinal fusion, and the recommendation is weak due to low-certainty evidence. Meanwhile, further longitudinal studies are required to validate these findings.