Comparison of lumbar interbody fusion with PEEK cage, titanium-coated PEEK cage and 3D-printed porous titanium cage for the treatment of lumbar degenerative disease: a systematic review and network meta-analysis

Abstract Background As two classic representative materials, solid titanium cages and uncoated PEEK cage (UPC) each have distinct inherent advantages and limitations, and 3D-printed porous titanium cage (3DPPTC) and titanium-coated PEEK cage (TCPC) have been increasingly applied in clinical practice. Methods This study was in accordance with the NMA PRISMA Statement. A comprehensive search was conducted in the PubMed, Embase and Web of Science Core Collection databases from inception to January 26, 2026. The fusion rate and subsidence rate were evaluated via odds ratios and 95% confidence intervals. A random-effects model was applied. Results A total of 9 RCTs and 20 nonrandomized studies were included after screening. The fusion rates of 3DPPTC (OR, 3.08; 95% CI, 1.54, 6.15) and TCPC (OR, 2.46; 95% CI, 1.10, 5.51) at 6-month follow-up were statistically greater than that of UPC. The fusion rate of 3DPPTC at 1 year was statistically greater than those of TCPC (OR, 2.02; 95% CI, 1.25, 3.26) and UPC (OR, 2.07; 95% CI, 1.42, 3.02). The subsidence rate of 3DPPTC at the 6-month follow-up was statistically lower than that of UPC (OR, 0.41; 95% CI: 0.19–0.90). Notably, only 2 included studies provided direct head-to-head comparisons between 3DPPTC and TCPC, and the comparative evidence between these two cage types relies predominantly on indirect analyses. Conclusion Both 3DPPTC and TCPC improved early postoperative bone fusion at the 6-month follow-up. At the 1-year follow-up, 3DPPTC statistically increased the fusion rate compared with TCPC. 3DPPTC reduced the risk of cage subsidence at 6-month follow-up compared with UPC. However, comparisons between 3DPPTC and TCPC rely predominantly on indirect evidence, with only 2 studies providing direct comparative data. This limitation may reduce the confidence in the conclusion regarding the relative advantages of 3DPPTC over TCPC, and the overall findings should be interpreted with appropriate caution. The present network meta-analysis focused exclusively on radiological outcomes as core endpoints. Radiological superiority may not directly indicate superior clinical efficacy. PROSPERO registration number CRD420261299880.