Comparing Lumbar Spine Cages and Bone Grafts in Spinal Arthrodesis: A Meta-Analysis of Clinical Outcomes.

INTRODUCTION AND AIM

The role of interbody cages in lumbar arthrodesis remains debated despite widespread adoption. This meta-analysis aimed to compare clinical and radiological outcomes between synthetic cages and structural bone grafts in lumbar fusion surgery from the latest updated evidence based on subgroup-based analysis and stratification of outcomes.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to conduct a literature search across major databases through December 2024. Studies comparing lumbar interbody fusion outcomes between cage and bone graft cohorts were included in this analysis. Random-effects meta-analyses were performed for fusion rates, radiographic parameters, clinical outcomes, and complications. Subgroup analyses stratified results by surgical approach, cage material, and graft type.

RESULTS

Twenty studies (1,452 patients) met inclusion criteria. Cage utilization demonstrated significantly higher fusion rates (96.3% versus 90.8%, RR=2.74, p=0.03) and greater disc height maintenance (MD=0.73 mm, 95% CI=0.45-1.01). Polyetheretherketone (PEEK) cages showed superior fusion rates compared to titanium (RR=1.00 versus 0.94, p=0.042). Back pain improvement was greater in the cage group (MD=0.65, 95% CI=0.08-1.22), while complication and reoperation rates remained comparable. No significant differences were observed in lordosis restoration or Oswestry Disability Index (ODI) scores.

CONCLUSIONS

Synthetic cage implementation in lumbar arthrodesis is associated with superior fusion rates and disc height maintenance, especially with PEEK devices. These benefits occur without increased complications, supporting cage utilization in appropriate clinical scenarios. Future studies should focus on long-term outcomes and cost-effectiveness analyses.