The Pericapsular Nerve Group (PENG) Block Combined With Local Infiltration Analgesia (LIA) Compared to Placebo and LIA in Hip Arthroplasty Surgery

A Multi-center Double-blinded Randomized-controlled Trial

D.-Yin Lin; Brigid Brown; Craig Morrison; Nikolai S. Fraser; Cheryl S. L. Chooi; Matthew G. Cehic; David H. McLeod; Michael D. Henningsen; Nikolina Sladojevic; Hidde M. Kroon; Ruurd L. Jaarsma


BMC Anesthesiol. 2022;22(252) 

In This Article

Abstract and Introduction


Background: The PEricapsular Nerve Group (PENG) block is a novel regional analgesia technique that provides improved analgesia in patients undergoing hip surgery while preserving motor function. In this study the PENG block was investigated for analgesia in elective total hip arthroplasty (THA).

Methods: In this multi-centre double-blinded randomized-controlled trial, in addition to spinal anesthesia and local infiltration analgesia (LIA), THA patients received either a PENG block or a sham block. The primary outcome was pain score (numeric rating scale 0–10) 3 h postoperatively (Day 0). Secondary outcomes were postoperative quadriceps muscle strength, postoperative Day 1 pain scores, opiate use, complications, length of hospital stay, and patient-reported outcome measures.

Results: Sixty patients were randomized and equally allocated between groups. Baseline demographics were similar. Postoperative Day 0, the PENG group experienced less pain compared to the sham group (PENG: 14 (47%) patients no pain, 14 (47%) mild pain, 2 (6%) moderate/severe pain versus sham: 6 (20%) no pain, 14 (47%) mild pain, 10 (33%) moderate/severe pain; p = 0.03). There was no difference in quadriceps muscle strength between groups on Day 0 (PENG: 23 (77%) intact versus sham: 24 (80%) intact; p = 0.24) and there were no differences in other secondary outcomes.

Conclusions: Patients receiving a PENG block for analgesia in elective THA experience less postoperative pain on Day 0 with preservation of quadriceps muscle strength. Despite these short-term benefits, no quality of recovery or longer lasting postoperative effects were detected.


Total hip arthroplasty (THA) is a cost-effective treatment for osteoarthritis through reduction in pain and improvement in quality of life.[1] It is increasingly performed in an aging population with a total of 32,929 THAs performed in Australia in 2017—2018 (133:100,000 population).[2] THA is associated with significant postoperative pain and high rates of analgesia use,[3] with incidences of opioid prescribing following THA as high as 89.7%.[4,5]

Adequate pain management following THA is important as quality analgesia has been shown to decrease complication rates and facilitate postoperative mobilization.[6,7] Previous THA studies have suggested a multimodal analgesia approach to decrease reliance on opioid based medications to reduce associated side-effects.[3,8] Regional analgesia is an important part of this multimodal approach. Commonly performed regional analgesia techniques include the femoral nerve block, fascia iliaca block, or the lumbar plexus block. The major disadvantage of these regional techniques commonly used for THA is that they have only been partially effective in reducing pain and frequently result in motor weaknesses, delaying mobilization.[9,10]

In 2018, Giron-Arango et al. described a novel regional technique for hip analgesia; the pericapsular nerve group (PENG) block.[11] The PENG block is a plane block placed under ultrasound guidance at the level of the anterior inferior iliac spine, targeting the articular branches of the femoral nerve, obturator nerve, and accessory obturator nerve.[12] Randomized-controlled trials investigating the efficacy of PENG have shown improved analgesia while preserving motor function and quadriceps muscle strength, enabling postoperative mobilization and improved quality of recovery.[13–15]

A common technique used for THA is spinal anesthesia in combination with local infiltrating analgesia (LIA). However, this approach is largely based on favourable results of LIA in knee arthroplasty with limited effect in postoperative pain control in THA.[16] Little is known of the addition of PENG in THA with LIA. This double-blinded randomized-controlled trial was conducted to test the efficacy of the addition of PENG in THA compared with the standard of LIA alone, using a sham block as control.

The primary outcome was the NRS pain score at Day 0. Secondary outcomes were: NRS pain score (at Day 1), Day 0 and 1 quadriceps muscle strength, perioperative opiate use, postoperative complications, length of hospital stay, patient satisfaction and PROMs.