Risk factors for failure of reduction of anterior glenohumeral dislocation without sedation

Background: Although anterior glenohumeral dislocations are common, the reduction procedure is often difficult, requiring sedation or anesthesia. To date, the risk factors for reduction failure without sedation have not been fully investigated. This study aimed to clarify the predictive factors that render the reduction of anterior glenohumeral dislocation without sedation difficult by use of multivariate analyses. Methods: We retrospectively reviewed 156 patients who underwent attempted reduction of anterior glenohumeral dislocation between 2006 and 2019. Patients were included based on the following criteria: traumatic dislocation, undergoing attempted reduction using the traction-countertraction method, and acute dislocation in which reduction was attempted within 2 days of the injury. The dependent variable was set as an irreducible glenohumeral dislocation without sedation, which was defined as a reduction failure in this study. Explanatory variables included age, sex, side of injury, recurrent dislocation, axillary nerve injury, time from dislocation to attempted reduction, greater tuberosity fracture, humeral neck fracture, glenoid rim fracture, and glenohumeral osteoarthritis. We evaluated these outcomes from radiographs and clinical notes. Univariate and multivariate analyses were performed. Baseline variables, which were observed to be significant in the univariate analysis, were included in multivariate models, which used logistic regression to identify independent predictors of reduction failure. Results: Of the 156 patients, 25 (16.0%) experienced reduction failure. Multivariate analyses showed that older age (≥55 years) (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.1-10.4; P = .036), greater tuberosity fractures (OR, 3.6; 95% CI, 1.1-12.2; P = .033), and glenoid rim fractures (OR, 11.5; 95% CI, 1.5-87.7; P = .018) were risk factors for reduction failure. Conclusions: Our results demonstrated that multiple factors were associated with unsuccessful reduction of anterior glenohumeral dislocation without sedation. In elderly patients or patients with concurrent greater tuberosity fractures and glenoid rim fractures, reduction failure could occur in the absence of sedation; thus, the administration of sedatives or anesthesia should be considered.