Table 1 Inclusion and exclusion criteria

age between 18 and 75 years indication for the application of a distal sciatic catheter within the scope of an elective surgical procedure patient consent

patient diagnosed with chronic pain prior to surgery polyneuropathy or ipsilateral neuropathy, involving the lower limb refusal of regional anesthesia patient not legally competent intolerance or allergy to ropivacaine or oxy-codone neuromuscular diseases BMI > 35 kg/m.² pre-existing opioid medication due to the injury to be operated on