Halo, Collar, Anterior or Posterior Fusion? Comparative Outcomes in Typical and Atypical Hangman’s Fractures: A Systematic Review of fusion rate and complication profile

Systematic review OBJECTIVE: Hangman's fracture, a traumatic spondylolisthesis of the C2 vertebra, represents a significant challenge in cervical spine management due to its complex anatomy and biomechanical considerations. Management strategies range from non-surgical immobilization (rigid collar, halo vest) to surgical stabilization (anterior cervical discectomy and fusion [ACDF], posterior fusion or combination of both anterior and posterior approaches). This systematic review evaluates fusion rates and complication profiles associated with collar, halo, ACDF, and posterior fusion in typical and atypical Hangman's fractures. We systematically searched PubMed, Ovid Medline, Scopus, and Google Scholar for peer-reviewed studies up to June 2025. Eligible studies included patients with typical or atypical Hangman's fractures managed surgically or conservatively. Quality was assessed using NIH and JBI tools. Fifty-two studies (1,101 patients, mean age 41.6 years, range 7-94) were included. Non-surgical treatments (collar, halo) achieved high union rates, though halo required prolonged immobilization and was associated with pin-site infections. ACDF (primarily C2-C3 with plating) and posterior fusion demonstrated comparable fusion success. ACDF was associated with dysphagia, aspiration pneumonia, and hoarseness, while posterior fusion carried higher risks of hardware loosening, screw-related complications, infection, and greater intraoperative blood loss. In atypical fractures (123 patients), all approaches achieved fusion, though recovery duration varied. While fusion is achievable with all approaches, failure rates exist particularly in posterior fusion for atypical Hangman's fractures. Complication patterns also vary between anterior and posterior techniques. No single method is universally superior; treatment should be tailored to fracture type, patient factors, and surgeon expertise. Prospective multicenter trials are needed to refine surgical indications and long-term outcomes.