Is There a Difference in the Outcomes of Adolescent Idiopathic Scoliosis Deformity Correction with the Type of Rod (Titanium vs. Cobalt-chrome) Used? A Systematic Review and Meta-analysis.

INTRODUCTION: As biomaterial technology advances, rods made of cobalt-chromium appear to be an option for correcting deformities in adolescent idiopathic scoliosis (AIS). This study aimed to compare the efficacy of titanium and cobalt-chrome rods in correcting the deformity and to compare the clinical outcomes between the two groups. METHODS: Two independent reviewers performed a literature search using PubMed, EMBASE, Scopus, and Google Scholar databases. The search focused on identifying articles that compared the surgical treatment of AIS using titanium and cobalt-chromium rods. RESULTS: Six studies were included for qualitative and quantitative analysis, along with interpretation, of which one was a randomized controlled trial, while the rest of the five were cohort studies. Three hundred thirty-two subjects were part of the studies. There was no significant difference noted in either Cobb's angle of the primary curve at the final follow-up (standardized mean difference [SMD] - 0.14, 95% confidence interval [CI] (-0.23)-0.51) or the correction rate (SMD - (-0.01), 95% CI (-0.67)-0.36). A trend toward lower final kyphosis was noted in the titanium group, although it was statistically not significant (SMD - (-0.21), 95% CI (-0.43)-0.01). CONCLUSION: No significant difference in outcomes or complication rates was noted following the use of either the titanium or cobalt-chromium rods. The advantages and disadvantages of both of these biomaterials should be considered before routine usage in AIS surgeries. Further studies with high power and validity using randomization, blinding, and higher sample size, preferably multicentric with longer follow-ups, are recommended.Level of Evidence - III.