2.1. Search strategy and study selection

Two independent reviewers (JMM and LT) performed a literature search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guidelines (Liberati et al., 2009). Any disagreements regarding study inclusion were resolved by consulting the opinion of a senior author (SD or JSB). A comprehensive search was performed for eligible articles using the PubMed/Medline, Embase, and Cochrane databases to include studies up to, and including July 10th, 2022 (PROSPERO ID: 353,719). Search terms included “anterior cervical surgery” AND (“randomised controlled trial” OR “randomised controlled trial” OR “RCT” OR “trial” OR “random”) AND (“spacer” OR “plate” OR “screw” OR “cage”) AND (“outcomes” OR “complications” OR “dysphagia” OR “pain” OR “function”) AND (“follow-up”). Reference lists of full-text articles were reviewed and screened for further studies meeting the inclusion criteria.