Background: Traumatic spondylolisthesis of the axis, is a common cervical spine fracture; however, to date there is limited data available to guide the treatment of these injuries. The purpose of this review is to provide an evidence-based analysis of the literature and clinical outcomes associated with the surgical and nonsurgical management of hangman's fractures.
Methods: A systematic literature search was conducted using PubMed (MEDLINE) and Scopus (EMBASE, MEDLINE, COMPENDEX) for all articles describing the treatment of hangman's fractures in 2 or more patients. Risk of nonunion, mortality, complications, and treatment failure (defined as the need for surgery in the nonsurgically managed patients and the need for revision surgery for any reason in the surgically managed patients) was compared for operative and nonoperative treatment methods using a generalized linear mixed model and odds ratio analysis.
Results: Overall, 25 studies met the inclusion criteria and were included in our quantitative analysis. Bony union was the principal outcome measure used to assess successful treatment. All studies included documented fracture union and were included in statistical analyses. The overall union rate for 131 fractures treated nonsurgically was 94.14% [95% confidence interval (CI), 76.15-98.78]. The overall union rate for 417 fractures treated surgically was 99.35% (95% CI, 96.81-99.87). Chance of nonunion was lower in those patients treated surgically (odds ratio, 0.12; 95% CI, 0.02-0.71). There was not a significant difference in mortality between patients treated surgically (0.16%; 95% CI, 0.01%-2.89%) and nonsurgically (1.04%; 95% CI, 0.08%-11.4%) (odds ratio, 0.15; 95% CI, 0.01-2.11). Treatment failure was less likely in the surgical treatment group (0.12%; 95% CI, 0.01%-2.45%) than the nonsurgical treatment group (0.71%; 95% CI, 0.28%-15.75%) (odds ratio 0.07; 95% CI, 0.01-0.56).
Conclusion: Hangman's fractures are common injuries, and surgical treatment leads to an increase in the rate of osteosynthesis/fusion without significantly increasing the rate of complication. Both an anterior and a posterior approach result in a high rate of fusion, and neither approach seems to be superior.