Interim analysis

Total knee arthroplasty (TKA) is associated with moderate to severe postoperative pain. Although epidural treatment provides good and reliable postoperative pain relief after THA, it may cause urinary retention, nausea, hypotension, diminished muscle control, and delayed mobilization.

The challenge of new analgesic regimes is to reduce the occurrence of side effects while maintaining adequate pain relief and maximum muscle control. A relatively new method to provide postoperative pain relief after TKA is local infiltration analgesia combined with single-shot injection(s) or continuous infusion of local anesthetics into the surgical site. As local infiltration analgesia combined with continuous intraarticular infusion compared with continuous epidural infusion has not been evaluated, our study was designed to determine whether this technique could enhance analgesia and improve patient outcome after TKA. This study compares continuous epidural infusion of Ropivacaine and intravenous Ketorolac with local infiltration analgesia with Ropivacaine, Ketorolac and Adrenaline combined with continuous intraarticular infusion of Ropivacaine and Ketorolac.

Inclusion Criteria:

• Patients admitted consecutively to primary total knee arthroplasty.
• Provided informed consent

Exclusion Criteria:

• Fertile women with positive pregnancy test, nursing mothers, fertile women who do not use safe contraception
• Severe chronic neurogenic pain
• Medical treated diabetes
• Contraindications for spinal aesthesia and epidural analgesia
• Known hypersensitivity towards study drugs
• Rheumatoid arthritis
• Treatment with narcotics
• Treatment with antidepressants
• Severe obesity BMI>35
• Treatment with antacid
• Not able to speak and understand Danish