Clinical and radiological outcomes of titanium cage versus polyetheretherketone cage in lumbar interbody fusion: a systematic review and meta-analysis

Interbody cages are widely used in lumbar interbody fusion (LIF). The aim of this meta-analysis is to compare the clinical and radiological outcomes between titanium (Ti) and polyetheretherketone (PEEK) cages in patients underwent LIF. A literature search was conducted in PubMed, Embase, Web of Science, and the Cochrane library databases until October 2023. Studies comparing the clinical and radiological outcomes of Ti and PEEK cages in LIF were included. Subgroup analyses was performed to differentiate between patients who had three-dimensional printed titanium (3D-Ti) cage and non-3D Ti cage. A total of 19 studies with 820 Ti cages patients (including 476 patients with 3D-Ti cages) and 1237 PEEK cages patients were reviewed. Ti cages demonstrated advantages of better fusion rate, and lower cage subsidence and reoperation rate than PEEK cages. Patients with 3D-Ti cages showed significantly superior fusion rate, less cage subsidence rate and reduced reoperation rate by conducting subgroup analysis. No significant difference was found between non-3D Ti cages and PEEK cages in fusion, cage subsidence and reoperation rate. Both Ti and PEEK cages patients had similar postoperative visual analogue score, Oswestry disability index score, anterior disc height, intervertebral foraminal height, global lumbar lordosis and segmental lordosis. 3D-Ti cages have advantages over PEEK cages in promoting fusion rate, reducing risk of cage subsidence and lowering reoperation rate. 3D-Ti cage may be a superior implant compared with PEEK cage in LIF.