A randomized clinical trial comparing six techniques of postoperative analgesia for elective total hip arthroplasty under subarachnoid anesthesia with opioids.

Background: Optimal control of acute postoperative pain and prevention of chronic persistent pain in total hip arthroplasty (THA) remain a challenge. The main hypothesis was that peripheral nerve blocks improve postoperative analgesia.

Methods: Immediate postoperative pain (24 hours) was evaluated every hour in 510 patients using a verbal rating 11-point scale for patient self-reporting of pain (VRS-11).