Titanium (Ti) cages may be superior to polyetheretherketone (PEEK) cages in lumbar interbody fusion: a systematic review and meta-analysis of clinical and radiological outcomes of spinal interbody fusions using Ti versus PEEK cages

Interbody cages are commonly used to augment interbody fusion. Commonly used materials include titanium (Ti) and polyetheretherketone (PEEK), with their inherent differences. The aim of this study is to perform a systematic review and meta-analysis to compare between the various clinical and radiological outcomes of Ti and PEEK interbody spinal cages. A systematic review and meta-analysis comparing clinical and radiological outcomes between Ti and PEEK interbody cages in patients undergoing spinal fusion was performed. PubMed, Scopus, Web of Science, Embase, and Cochrane Central Register of Controlled Trials database were searched. All studies that compared the clinical and radiological outcomes of patients who underwent Ti and PEEK cages were included. Subgroup analyses was performed to differentiate between patients who had cervical and lumbar interbody fusion. A total of 11 articles were identified, with a total of 743 patients. Spinal fusion rates at final follow-up did not differ between Ti and PEEK cages (OR 1.50, 95% CI 0.57–3.94, P = 0.41), although in patients undergoing lumbar fusion, Ti cages demonstrated superior fusion (OR 2.12, 95% CI 1.05–4.28, P = 0.04). In patients with non-infective etiologies, Ti cages had a higher rate of cage subsidence (RR 2.17, 95% CI 1.13–4.16, P = 0.02). Both types of cages had similar operating time, postoperative hematoma formation, neuropathic pain, segmental angle correction and postoperative clinical outcome improvement. In non-infective lumbar spine conditions, Ti cage may be the superior option due to the higher fusion rate. III.