Study DesignCross sectional.ObjectiveSpin bias, where authors distort findings to overstate efficacy, is prevalent in the medical literature. The comparative superiority of polyetheretherketone (PEEK) and titanium (Ti) cages in spinal fusion remains controversial. This study aims to assess the prevalence of spin bias in meta-analyses and systematic reviews comparing PEEK vs Ti cages in spinal fusion.MethodsThe PubMed, Embase, and Web of Science databases were searched to identify meta-analyses and systematic reviews comparing PEEK and titanium cages in spinal fusion. Included studies were assessed for the presence of the 9 most severe types of spin bias. This study also graded the quality of these articles using A Measurement Tool to Assess systematic Reviews 2 (AMSTAR 2) criteria.ResultsThe search resulted in 2352 articles, of which 13 met the inclusion criteria. Spin bias was identified in 8/13 (61.54%) of the included studies, with the most prevalent types being Type 3 (38.46%) and Type 5 (30.77%). Using AMSTAR 2, 1/13 (7.69%) studies were rated as critically low quality, 4/13 (30.77%) as low, 8/13 (61.54%) as moderate, with none rated as high.ConclusionsSpin was found in 61.54% of the reviews comparing PEEK and Ti cages in spinal fusion, with none achieving a high-quality rating. Surgeons must critically evaluate these articles for bias prior to utilizing them in clinical decision making.
Keywords: PEEK cages; bias; fusion; spin; spine; titanium.