[Patients with pre-existing chronic pain and/or psychological problems].

Existing pain chronification and psychological problems can affect the degree of perioperative pain and hence the postoperative outcome. Most elective surgery performed on the musculoskeletal system is indicated because of pain. To avoid perioperative complications it is therefore essential to identify patients with existing pain chronification before surgery is performed. Based on a systematic literature review, studies on orthopaedic surgery were filtered for existing pain chronification and checked in order to deduce clinically relevant and evidence-based recommendations. In summary, unproblematic pain is characterised by good organic explainability, lack of pain generalisation, no additional physical complaints, appropriate management of the physical damage encountered and suitable use of analgesics. In line with what is known about the mechanisms of pain chronification, patients with existing chronification usually display additional psychological problems. These psychological factors ought to be established prior to surgery. A preliminary non-surgical treatment could potentially also lead to a reassessment of the indication for surgery.