A Comparison of the Effect on Postoperative Pain between Lateral Femoral Cutaneous Nerve Block and Local Infiltration Anesthesia after Total Hip Arthroplasty: A Randomized Trial

Aims: No gold standard for pain management after total hip arthroplasty (THA) exists. This prospective, randomized, open-label study aimed to determine whether lateral femoral cutaneous nerve block and local infiltration analgesia (LIA) were effective analgesic adjuvants to femoral nerve block (FNB) after THA. 
Study Design: Prospective, randomized, open-label trial. 
Place and Duration of Study: Department of Anesthesia, Nagasaki Rosai Hospital, Sasebo, Japan between April 2019 and May 2020. 
Methodology: This study included 50 patients who underwent THA under total intravenous anesthesia using propofol. All patients received ultrasound-guided FNB using 0.25% levobupivacaine 20 mL before the operation. Patients were randomly allocated to one of the following two groups: Group B (n=25), which received ultrasound-guided lateral femoral cutaneous nerve block with 0.25% levobupivacaine 20 mL after FNB; and Group I (n= 25), which received 0.25% levobupivacaine 20 mL over the incision line into the muscle, and the subcutaneous, and cutaneous tissue along the wound edge after the fascia closure. All patients received 1000 mg intravenous acetaminophen before the end of the operation, and at 6, 12, 18, and 24 h after the operation. The patients received 50 mg of diclofenac sodium, as rescue analgesics, if needed. Nursing staff evaluated the postoperative pain using a numerical rating scale (NRS) at 0, 1, 3, 6, 12, 18, and 24 h postoperatively. 
Results: No significant difference was observed in patient characteristics, except the operative time, between the groups. Additionally, no significant difference was found in NRS and in the frequency of rescue analgesics during the study period between the groups. 
Conclusion: We concluded that both lateral femoral cutaneous nerve block and LIA with FNB would have the equivalent adjunctive analgesic effect after THA.