Impact of the pericapsular nerve group (PENG) block on postoperative analgesia and functional recovery following total hip arthroplasty: a randomised, observer-masked, controlled trial

Abstract

The pericapsular nerve group (PENG) block is a novel regional anaesthesia technique that aims to provide hip analgesia with preservation of motor function, although evidence is currently lacking. In this single-centre, observer-masked, randomised controlled trial, patients undergoing total hip arthroplasty received pericapsular nerve group block or no block (control group). Primary outcome measure was maximum pain scores (0-10 numeric rating scale) measured in the first 48 h after surgery. Secondary outcomes included postoperative opioid consumption; patient mobilisation assessments; and length of hospital stay. Sixty patients were randomly allocated equally between groups. The maximum pain score of patients receiving the pericapsular nerve group block was significantly lower than in the control group at all time-points, with a median (IQR [range]) of 2.5 (2.0-3.7 [0-7]) vs. 5.5 (5.0-7.0 [2-8]) at 12 h; 3 (2.0-4.0 [0-7]) vs. 6 (5.0-6.0 [2-8]) at 24 h; and 2.0 (2.0-4.0 [0-5]) vs. 3.0 (2.0-4.7 [0-6]) at 48 h; all p < 0.001. Moreover, the pericapsular nerve group showed a significant reduction in opioid consumption, better range of hip motion and shorter time to ambulation. Although no significant difference in hospital length of stay was detected, our results suggest improved postoperative functional recovery following total hip arthroplasty in patients who received pericapsular nerve group block.

Trial registration: ClinicalTrials.gov NCT04306133.

Keywords: anaesthesia; analgesia; arthroplasty; hip surgery; postoperative pain.

Figure 1

PENG block via a lateromedial approach. Once the needle was placed in the plane between the iliopsoas tendon (IPT) and periosteum and between the anterior inferior iliac spine (AIIS) and iliopubic eminence (IPE), the PENG block was performed by injecting 20 ml of local anaesthetic, the spread of which is visible under the iliopsoas muscle (IPM). Arrow, needle pathway; blue dashed line, local anaesthetic spread; FA, femoral artery. Asterisk, needle entry point.

Figure 2

Study flow diagram.

Figure 3

Maximum postoperative (numeric rating scale) pain scores in both study groups reported during three postoperative intervals. Values are median (horizontal bars), IQR (box) and range (whiskers). *denotes statistical significance (p < 0.05); PENG, pericapsular nerve group block.

Figure 4

Patient‐controlled administration of sublingual sufentanil among the two groups in the first 48 h after surgery. Dots are the number of sufentanil tablets taken by each patient. PENG, pericapsular nerve group block.