In 2015, more than 50% of surgical procedures were performed in outpatient settings. Successful pain management after outpatient surgery is crucial, and requires a perfect cooperation between caregivers and patients, with clear information on the analgesics use at home. Different strategies to control postoperative pain were adopted by hospitals performing outpatient surgery. However, up to half of patients receive little or no information about the treatment of postoperative pain, and at least one third of them are not able to follow postoperative analgesia instructions. There is a clear unmet need in pain treatment during first 48-72 hours after discharge, with important number of emergency calls and readmissions. The most common causes of rescue calls after outpatient surgery are uncontrolled pain and questions about medications or post-operative care.

Structured education interventions using psychological techniques to enhance engagement and behavior were found to be beneficial for better acute pain management in outpatient settings after orthopedic surgery.

We hypothesize that an educational intervention based on the rational perception of postoperative pain and discomfort, and the proper use of analgesics would improve the quality of pain management at home and reduce analgesics-related side effects.

Principal objective of this study is to evaluate the impact of a preoperative educational intervention on effectiveness of postoperative pain self-management in outpatient settings compared to the current practice.

Secondary objectives are to evaluate the prevalence of analgesics use and the incidence of severe pain episodes, as well as side effects. The occurrence of neurological pain, quality of sleep, and patient's comfort will be evaluated at 30th day after surgery.

Inclusion Criteria:

• Adults (age ≥ 18 years);
• Patients scheduled for outpatient orthopedic surgery
• ASA (American Society of Anesthesiology) I to III;
• Patients admitted for an outpatient intervention resulting in moderate to severe pain: eg: arthroscopy of the knee or shoulder, cruciate ligaments, shoulder block, medial patellofemoral ligament plasty (not exhaustive)

Exclusion Criteria:

• Pregnant or lactating women
• Patients with contraindications to paracetamol and/or second-level analgesic and/or NSAIDs (hepatocellular insufficiency, respiratory insufficiency, substituted or unsubstituted drug addicts, allergy to one of the drugs, history of bleeding or digestive perforation during previous NSAID treatment, history of gastroduodenal ulcer, renal failure with clearance <50mL / min, severe heart failure)
• Patients with preoperative chronic pain (outside operative site, known or detected by DN4)
• Patients admitted for an outpatient arthroplasty (excluded because they are subjected of a specific preoperative preparation)
• Persons deprived of their liberty by a judicial or administrative decision, persons under psychiatric care, persons admitted to a health or social establishment for other purposes than research
• Patient with a poor understanding of French
• Patient refusing to participate to the study
• Patient not affiliated to a social security regimen
• Patient participating in other interventional research except a routine care research (former regulation) and/or research with no interference with the primary endpoint analysis as determined by the investigator.