- Objective: To evaluate the prevalence of iatrogenic humeral neck fracture after attempted closed reduction in patients older than 40 years who present with a first-time anterior dislocation. Design: Retrospective cohort study, evidence-based medicine level IV. Patients: Ninety-two patients older than 40 years (mean 66.6 years of age) with a first-time anterior dislocation of the shoulder. Intervention: Closed reductions by the emergency medicine physicians under conscious sedation, in the emergency department. Main Outcome Measurements: Prevalence of iatrogenic fracture on postreduction radiographs. Results: Nineteen (20.7%) patients were diagnosed with a concomitant greater tuberosity fracture on initial radiograph. In the postreduction radiographs, 5 patients (5.4%) were identified with a postreduction humeral neck fracture, and all of them had a greater tuberosity fracture on initial radiographs. A highly significant association (P < 0.0001) was observed between the finding of a greater tuberosity fracture on the initial radiographs and the occurrence of iatrogenic humeral neck fracture after close reduction. Discussion: Previous case reports have described an iatrogenic humeral neck fracture with reduction attempt of shoulder dislocation. In our retrospective study, 21% of the cohort of patients older than 40 years had a concomitant greater tuberosity fracture; 26% of them had an iatrogenic humeral neck fracture after reduction attempt under sedation in the emergency room. These patients ended up with poor outcome. Conclusions: Patients older than 40 years, presenting with a first-time anterior shoulder dislocation with an associated fracture of the greater tuberosity have a significant rate of iatrogenic humeral neck fracture during closed reduction under sedation. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.