Blocking the pericapsular nerve group against the lumbar erector spinae plane for pain management following total hip replacement: A randomized controlled trial

Both the pericapsular nerve group block (PENG) and the lumbar erector spinae plane block (L-ESPB) are emerging regional anesthetic techniques, yet comparative data remain limited.

This randomized, controlled study included 60 patients undergoing THA, assigned to receive either a PENG block (n = 30) or an L-ESPB (n = 30). The primary outcome was the time to the first analgesic request. Secondary outcomes included total analgesic consumption, pain scores measured by the numeric rating scale (NRS) at rest and during movement, assessment of quadriceps motor strength, and any block-related complications. All participants were administered a standardized multimodal analgesic protocol.

The PENG group demonstrated a significantly longer time to the first analgesic request compared to the L-ESPB group (12.88 ± 4.56 hour vs. 8.45 ± 3.49 hours; P < 0.001) and lower total analgesic consumption (25.84 mg ± 5.59 mg vs. 40.18 mg ± 7.89 mg; P < 0.001). Resting NRS scores were comparable early postoperatively but were significantly lower in the PENG group at 24 hours. Dynamic pain scores were consistently lower in the PENG group across all time points. Quadriceps motor weakness was more frequent in the PENG group at 6 hours (P = 0.04), but resolved completely by 12 hours. No major complications were observed in either group.

For postoperative analgesia following THA, the PENG block is superior to L-ESPB, offering prolonged analgesia and reduced opioid requirements. Although transient quadriceps weakness may occur, it resolves early without clinical sequelae.