Optimal cage biomaterials for fusion and subsidence outcomes in lumbar spinal fusion: a network meta-analysis of 4881 patients
摘要
Interbody cage biomaterial influences fusion success and subsidence risk, key determinants of surgical failure or revision. While PEEK is widely used, it may be inferior in osseointegration. Alternatives such as solid-titanium (Ti), titanium-coated PEEK (TiPEEK), and 3D-printed titanium (3DPTi) tantalum (3DPTn), or silicon nitride (Si₃N₄) offer advantages. Limited head-to-head trials and prior meta-analyses warrant a network meta-analytic approach for comparative synthesis across cage types. The aim of this study is to compare fusion, subsidence rates, and related outcomes across interbody cage biomaterials used in lumbar fusion for degenerative spine disease.
MethodsA systematic review and frequentist NMA was conducted following PRISMA-NMA guidelines. PubMed, Embase, and Scopus were searched through January 2025. Comparative studies assessing lumbar interbody cage biomaterials with ≥ 12-month fusion or subsidence outcomes were included. Risk of bias, transitivity, and network consistency were assessed.
ResultsForty-seven studies (n = 4881) were included. For fusion, 3DPTn showed the highest odds of radiographic success versus PEEK (OR 3.85, 95% CI 1.73–8.57), followed by 3DPTi (OR 2.78, 95% CI 1.92–4.02) and Si₃N₄ (OR 1.83, 95% CI 1.01–3.32). CaP-PEEK showed a non-significant trend toward improved fusion (OR 2.36, 95% CI 0.26–21.22). Both 3DPTi (OR 2.45, 95% CI 1.60–3.74) and 3DPTn (OR 3.39, 95% CI 1.63–7.06) remained superior to TiPEEK. For subsidence, 3DPTi (OR 0.45, 95% CI 0.29–0.70) and TiPEEK (OR 0.51, 95% CI 0.28–0.93) had significantly lower odds than PEEK, and also outperformed Ti (3DPTi: OR 0.24, 95% CI 0.10–0.61; TiPEEK: OR 0.27, 95% CI 0.10–0.61). Ranking analyses favored porous and composite cages. Sensitivity and inconsistency tests confirmed robustness.
Conclusion3DPTi, 3DPTn, Si₃N₄, and TiPEEK outperform PEEK in fusion and/or subsidence outcomes. CaP-PEEK showed a trend toward improved fusion but remains underpowered. These findings support biomaterial-specific cage selection and warrant further prospective validation.
Level of evidenceLevel 1.