Pericapsular nerve group block and lateral femoral cutaneous nerve block versus fascia iliaca block for multimodal analgesia after total hip replacement surgery: A retrospective analysis

Abstract

Background: Optimal pain control with limited muscle weakness is paramount for a swift initiation of physical therapy and early discharge. Fascia iliaca compartment block (FICB) has been recommended since it offers good pain control with a low risk of motor block. Pericapsular nerve group (PENG) block with lateral femoral cutaneous block (LFCN) has been proposed as an effective alternative to FICB that offers better pain control with a considerably lower risk of motor block. We aimed to compare the aforementioned blocks and determine which one yielded the lowest numeric rating scale (NRS) score. Methods: We designed a retrospective analysis of patients undergoing elective total hip arthroplasty. The primary outcome was the NRS score at 6, 12, and 24 hours. The secondary outcomes were total opioid consumption, time to first PRN opioid, and time to first postoperative ambulation. Results: 52 patients were recruited, (13 PENG plus LFCN, 39 FICB). PENG plus LCFN resulted in a lower NRS at all three-time points (mean difference and 95%CI at 6 h 0.378 [-0.483; 1.240], at 12 h 0.336 [-0.378; 1.050], and at 24 h 0.464 [0.013; 0.914] P = 0.02). Moreover, less PRN opioids were requested in the PENG plus LCFN vs. FICB group (0 [0;7.5] vs 60 [15;80] milligrams of morphine equivalents, P = 0.001). No delay in the first ambulation or initiation of physical rehabilitation was reported in either group. Conclusions: PENG plus LCFN seems to offer better pain control and lead to less PRN opioids. Neither block hindered physical therapy nor ambulation. These results need to be confirmed with a larger prospective and randomized study.