Pericapsular nerve group with lateral femoral cutaneous nerve block vs. suprainguinal fascia iliaca block for analgesia in total hip arthroplasty: a prospective comparative study

To comparepostoperative analgesia, opioid consumption, and early motor function between suprainguinal fascia iliaca block (SFIB) and pericapsular nerve group block combined with lateral femoral cutaneous nerve block (PENG+LFCN) in patients undergoing primary total hip arthroplasty (THA) under general anesthesia. In this single-center, prospective, non-randomized study, 48 adults undergoing posterolateral THA received either SFIB (0.25% bupivacaine 40 mL) or PENG+LFCN (0.5% bupivacaine 15 mL + 5 mL). Primary outcomes were pain scores measured using a visual analog scale (VAS) at rest and during movement at 3, 12, 24, and 48 h. Secondary outcomes included morphine use via patient controlled analgesia, quadriceps strength and physiotherapy participation. Exploratory analyses summarised total pain burden using area under the curve (AUC, 3–48 h) and time-weighted average pain (TWAP), with inverse probability of treatment weighting (IPTW) used as a sensitivity analysis. Rest VAS at 24 h was lower with SFIB (1.25) vs. PENG+LFCN (2.46): mean difference 1.21 (95% CI 0.31–2.10), p = 0.017. Morphine use at 12–24 h was lower with PENG+LFCN (0.75 vs. 1.88 mg): −1.13 mg (95% CI − 2.07 to − 0.18), p = 0.027; total 0–48 h consumption was similar (p = 0.114). Quadriceps weakness at 6 h was less frequent with PENG+LFCN (29.2% vs. 54.2%; OR 0.35, 95% CI 0.11–1.15), but this difference was not statistically significant; all patients recovered full strength by 24 h. Rest-pain AUC from 3 to 48 h was numerically higher with PENG+LFCN (difference 38.0 VAS·h, 95% CI 2.66–73.34; p = 0.065), with a similar pattern in the IPTW-weighted sensitivity analysis (ATE 50.15 VAS·h; p = 0.024); movement pain was similar between groups. SFIB and PENG+LFCN provided broadly comparable analgesia for THA, with modest, time-specific differences suggesting a potential trade-off between lower 24-h rest pain with SFIB and lower early opioid use and numerically fewer weakness events with PENG+LFCN. These findings are hypothesis-generating and require confirmation in larger randomized trials. ClinicalTrials.gov NCT06844162; retrospectively registered on 25 February 2025.