The purpose of the study is to compare the effects of per-operative local infiltration analgesia with ropivacaine 0,2 % (150 ML) versus placebo on acute postoperative pain intensity after total hip arthroplasty.

The hypothesis is that local infiltration analgesia reduces the acute postoperative pain intensity.

In spite of being one of the last century's most successful surgical procedures in treatment of advanced osteoarthritis total hip arthroplasty is still associated with postoperative pain and delayed rehabilitation. We therefore decided to evaluate the effects of per-operative local infiltration analgesia with ropivacaine 0,2 % (150 ML) versus placebo on acute postoperative pain intensity in a well defined, multimodal, fast-track setup after hip arthroplasty. The technique is widely used as standard treatment in many European centers despite its limited evidence.

Inclusion Criteria:

• Elective total hip arthroplasty
• Able to speak and understand danish
• Able to give informed consent

Exclusion Criteria:

• Alcohol or medical abuse
• Allergies to local anesthetics
• Age < 18 years
• Daily use of opioids or glucocorticoids
• Pregnancy or breastfeeding
• Opioid intolerance
• Obesity defined as BMI>40 kg/m2
• Diabetic neuropathy and rheumatoid arthritis