Titanium-coated PEEK Versus Uncoated PEEK Cages in Lumbar Interbody Fusion A Systematic Review and Meta-analysis of Randomized Controlled Trial

Study Design:Systematic review and meta-analysis. Objective:This study was performed to compare the fusion and subsidence rate of titanium-coated polyetheretherketone (Ti-PEEK) versus polyetheretherketone (PEEK) cages after lumbar fusion and to investigate the clinical effect on patient-reported outcomes (PROMs). Summary of Background Data:Ti-PEEK cages have been developed to combine the advantages of both titanium alloy and PEEK, but whether they are superior to uncoated PEEK cages in bone fusion is still inconclusive. Methods:PubMed, EMBASE, ISI Web of Science, CENTRAL, and CNKI were searched to identify randomized controlled trials that compared the efficacy of Ti-PEEK and PEEK cages in lumbar fusion. Difference in fusion rate and subsidence rate was indicated by risk ratio and its associated 95% confidence interval (95% confidence interval). Mean difference was calculated for Oswestry Disability Index and visual analogue scale for low back pain. Subgroup analysis was performed by time course after the surgery. The Grading of Recommendations, Assessment, Development and Evaluation approach was used to evaluate the certainty of evidence. Results:Four randomized controlled trials involving 325 patients (160 patients in Ti-PEEK group and 165 patients in PEEK group) that underwent lumbar fusion were included by our current study. Low to moderate evidence suggested that Ti-PEEK and PEEK cages exhibited equivalent fusion rate and subsidence rate at any follow-up time. Low to moderate evidence suggested that there was no difference in PROMs except for visual analogue scale measured at 6 months (mean difference: -0.57, 95% confidence interval -0.94, -0.21; P=0.002) but the difference was not clinically relevant according to the minimal clinically important difference. Conclusion:Low to moderate evidence showed that Ti-PEEK and PEEK had equivalent effect in bone fusion and cages subsidence at any follow-up time after lumbar fusion surgeries. Low to moderate evidence showed no clinically important difference in PROMs.