The PENG block has minimal effect on postoperative pain and length of stay in elective surgical hip dislocation: a multidisciplinary prospective randomized double-blind controlled trial

Abstract Background Pericapsular Nerve Group (PENG) block reduces pain and opioid consumption in hip arthroscopy. We compared the effects of PENG block versus placebo on pain, morphine consumption, and length of stay (LOS) in patients undergoing surgical hip dislocation (SHD). Methods Single-centre, parallel-group, prospective, randomized, double-blind, controlled trial of patients undergoing SHD for femoroacetabular impingement between June 2022 and November 2023. Both groups (PENG n = 38; placebo n = 33) underwent ultrasound-guided injection of 20 ml solution (PENG 0.5% ropivacaine, placebo 0.9% NaCl). We assessed pain at 1, 6, 12, and 24 h postoperatively using Visual Analogue Scale (VAS), total morphine consumption in Morphine Equivalent Dose (MED) during the first 24 h after surgery, and LOS in days. Results Median (range) VAS in the PENG group versus placebo group was 4 (0–8) versus 5 (1–10) at 1 h (P = .044); 3 (0–7) versus 3 (0–7) at 6 h (P = .614); 3 (0–8) versus 3 (0–8) at 12 h (P = .977); and 3 (0–6) versus 3 (0–7) at 24 h (P = .398). Mean ± SD 24-h morphine consumption was 48 ± 24 MED (PENG) versus 49 ± 29 MED (placebo; P = .842). Median (range) LOS was 3 (1–5) days (PENG) versus 3 (1–14) days (placebo; P = .250). Conclusion In this trial, PENG block only showed slight decrease in reported VAS at 1 h postoperatively compared to placebo, with no difference in morphine consumption and LOS after SHD.