Inclusion Criteria:  Patients with radiological confirmed anterior glenohumeral dislocation Patient affiliated or entitled to a social security scheme Oral informed consent form  Exclusion Criteria:  Glenohumeral fracture or vasculoneural lesion associated Dislocation for more than 12 hours Homolateral shoulder surgery antecedent Contraindication to other analgesics (morphine, sedation) BMI > 40 Patient < 18 year Pregnancy or nursing woment Person under guardianship or curatorship