Inclusion Criteria:  ≥18 years of age at screening Scheduled to undergo elective primary unilateral TKA American Society of Anaesthesiologists (ASA) physical status 1, 2 or 3 Mentally competent to provide informed consent, to report pain intensity and to use patient-controlled analgesia Physically able to perform independently the baseline functionality tests  Exclusion Criteria:  Obesity (BMI>40) Previous open knee surgery Revision TKA or bilateral TKA Contraindication to the following study medication: ropivacaine, morphine, midazolam, ketorolac, propofol, remifentanil, clonidine, dexamethasone, acetaminophen Uncontrolled anxiety, psychiatric, or neurological disorder that might interfere with study assessments Chronic widespread pain Radicular pain in index legClinical Study Protocol Version 1.0 Preoperative strong opioid use within 3 days before surgery (with the exception of weak opioids: tramadol and codeine) Any chronic neuromuscular deficit affecting the peripheral nerves or muscles of the surgical extremity Impaired kidney function (Chronic kidney disease (CKD) G4-G5 according to Kidney Disease: Improving Global Outcomes (KDIGO) classification) Alcohol or drug abuse Pregnant, nursing or planning to become pregnant before treatment. Women of reproductive age will be tested on pregnancy prior to start of the study. Participants who get pregnant after the treatment during the follow-up period will not be excluded