Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Apr 16:21925682251336750.
doi: 10.1177/21925682251336750. Online ahead of print.

Polyetheretherketone vs Titanium Cages in Spinal Fusion: Spin Bias in Abstracts of Systematic Reviews and Meta-Analyses

Henry Avetisian  1 , Apurva Prasad  1 , Kevin Mathew  1 , David McCavitt  1 , William J Karakash  1 , Dil Patel  1 , Jeffrey C Wang  1 , Raymond J Hah  1 , Ram K Alluri  1
Affiliations

Polyetheretherketone vs Titanium Cages in Spinal Fusion: Spin Bias in Abstracts of Systematic Reviews and Meta-Analyses

Henry Avetisian et al. Global Spine J. .

Abstract

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.

PubMed Disclaimer

Conflict of interest statement

The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Henry Avetisian, Apurva Prasad, Kevin Matthew, David McCavitt, and William Karakash have nothing to disclose. Jeffrey C. Wang has received intellectual property royalties from Zimmer Biomet, NovApproach, SeaSpine, and DePuy Synthes. Raymond J. Hah has received grant funding from SI bone, consulting fees from NuVasive, and support from the North American Spine Society to attend meetings. Ram K. Alluri has received grant funding from NIH, consulting fees from HIA Technologies, and payment from Eccential Robotics for lectures and presentations

Figures

Figure 1.
Figure 1.
PRISMA flowchart.
Figure 2.
Figure 2.
Total number of spin by article.
See this image and copyright information in PMC

References

    1. Kim YH, Ha KY, Rhyu KW, et al. Lumbar interbody fusion: techniques, pearls and pitfalls. Asian Spine J. 2020;14(5):730-741. - PMC - PubMed
    1. Zdeblick TA, Phillips FM. Interbody cage devices. Spine (Phila Pa 1976). 2003;28(15 Suppl):S2-S7. - PubMed
    1. Rao PJ, Pelletier MH, Walsh WR, Mobbs RJ. Spine interbody implants: material selection and modification, functionalization and bioactivation of surfaces to improve osseointegration. Orthop Surg. 2014;6(2):81-89. - PMC - PubMed
    1. Chong E, Pelletier MH, Mobbs RJ, Walsh WR. The design evolution of interbody cages in anterior cervical discectomy and fusion: a systematic review. BMC Musculoskelet Disord. 2015;16:99. - PMC - PubMed
    1. Lemcke J, Al-Zain F, Meier U, Suess O. Polyetheretherketone (PEEK) spacers for anterior cervical fusion: a retrospective comparative effectiveness clinical trial. Open Orthop J. 2011;5:348-353. - PMC - PubMed

LinkOut - more resources