The Indian Anaesthetists’ Forum

: 2020  |  Volume : 21  |  Issue : 1  |  Page : 1--3

Pericapsular nerve group block: Innovation or just a fad?

Anand M Sardesai, Ghansham Biyani 
 Department of Anesthesiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, Cambridge, UK

Correspondence Address:
Dr. Ghansham Biyani
Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, Cambridge, CB2 0QQ

How to cite this article:
Sardesai AM, Biyani G. Pericapsular nerve group block: Innovation or just a fad?.Indian Anaesth Forum 2020;21:1-3

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Sardesai AM, Biyani G. Pericapsular nerve group block: Innovation or just a fad?. Indian Anaesth Forum [serial online] 2020 [cited 2020 Aug 3 ];21:1-3
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Regional blocks such as fascia iliaca block (FIB), 3-in-1 block, femoral nerve (FN) block, and lumbar plexus block are frequently used as a part of anesthetic care plan for various hip joint procedures for their opioid-sparing effects and to provide postoperative pain relief.[1],[2],[3] However, none of the above-mentioned blocks are ideal as the articular branches of sciatic nerve to hip joint are spared. Moreover, weakness due to quadriceps femoris (QF) muscle involvement often impedes mobility in the immediate postoperative period, and questions are raised in the literature about the involvement of obturator nerve (ON) with the first two peripheral nerve blocks.[2],[3]

Recently described motor-sparing nerve block techniques for hip surgeries, such as pericapsular nerve group (PENG) block and iliopsoas plane block (IPB), are gaining popularity for their selective sensory effect.[4],[5] However, in this Editorial, we have only discussed the pros and cons of PENG block based upon the available literature so far.

A recent anatomical study performed on 13 cadaver hemipelvises by Short et al.[6] found that FN, ON, and accessory obturator nerve (AON) are the main nerves providing articular branches to anterior capsule, which is the richest innervated part of the hip joint. Subsequently, Girón-Arango et al.[4] developed a new ultrasound guided approach for blockade of these branches to the hip joint and termed it as the “PENG (PEricapsular Nerve Group) block.”

The most common indications to perform PENG block include total hip replacement, hip hemiarthroplasty, hip arthroscopy, and fracture neck of femur, among others.[5],[7] This block is performed with the patient in the supine position. A curvilinear low-frequency ultrasound probe (2–5 MHz) is initially placed in a transverse plane over the anterior inferior iliac spine and then aligned with the pubic ramus by rotating the probe either clockwise (on the right side) or counterclockwise (on the left side) by approximately 45°. However, Mistry et al.[8] have described the successful use of high-frequency linear probe in lean and thin patients as it provides detailed sonoanatomy to perform the block. Using either of the probe in this view, ilio-pubic eminence, iliopsoas muscle and tendon, femoral artery, and FN can be observed [Figure 1]. A 22G, 100-mm echogenic needle is then inserted from lateral to medial in an in-plane approach and is advanced toward the IPE, with the aim to place the tip of the needle between the psoas tendon anteriorly and the pubic ramus posteriorly [Figure 2]. Following negative aspiration, the local anesthetic (LA) solution is then injected in 5 ml increments up to a total volume of 20–30 ml, while observing for satisfactory spread of the LA solution [Figure 3].{Figure 1}{Figure 2}{Figure 3}

Many case reports and case series have reported successful use of PENG block for various hip joint interventions and found it to be highly effective in terms of providing postoperative pain relief without producing any motor weakness.[5],[9],[10] Involvement of FN, ON, and AON was consistently described in these reports. Although the depth and length the needle has to pass for the PENG block are deep and long, it can be performed easily and safely with single injection and has low rates of complications as there are no big blood vessels and vital structures present in the path of needle. Few randomized controlled trials (RCTs) are underway wherein the efficacy of PENG block is compared with FIB in hip surgeries as postoperative pain management technique and the results should be available early next year.

PENG block, like the other sensory blocks for hip joint namely IPB, is not a complete block as the articular branches of the sciatic nerve innervating the posterolateral capsule of the hip joint are not involved and hence cannot be used as sole anesthetic technique. In addition, the founders of IPB raised questions about the involvement of all the articular branches of FN with the use of PENG block.[11] Moreover, the analgesia accomplished by single-shot block is time limited and the degree of analgesia provided is moderate. As the capsule of hip joint is very close to the target needle site, the block should be performed with all aseptic precautions to avoid infection. Inadvertent QF weakness following the PENG block has been reported in two patients by Yu et al.[12]

In our opinion, PENG block can be a good and safe analgesic alternative to other regional blocks for various hip joint procedures, without producing any significant motor blockade. However, as there is only scarce evidence available in the literature, it is difficult for us to predict whether it is an innovation or just a fad. We hope that the results of RCTs should give us enough data to evaluate the clinical efficacy and outcome of this novel approach and keep the great interest and enthusiasm surrounding this motor-sparing sensory block intact in the near future.


1Indelli PF, Grant SA, Nielsen K, Vail TP. Regional anesthesia in hip surgery. Clin Orthop Relat Res 2005;441:250-5.
2Morau D, Lopez S, Biboulet P, Bernard N, Amar J, Capdevila X. Comparison of continuous 3-in-1 and fascia iliaca compartment blocks for postoperative analgesia: Feasibility, catheter migration, distribution of sensory block, and analgesic efficacy. Reg Anesth Pain Med 2003;28:309-14.
3Guay J, Parker MJ, Griffiths R, Kopp S. Peripheral nerve blocks for hip fractures. Cochrane Database Syst Rev 2017;5:CD001159.
4Girón-Arango L, Peng PW, Chin KJ, Brull R, Perlas A. Pericapsular nerve group (PENG) block for hip fracture. Reg Anesth Pain Med 2018;43:859-63.
5Nielsen ND, Greher M, Moriggl B, Hoermann R, Nielsen TD, Børglum J, et al. Spread of injectate around hip articular sensory branches of the femoral nerve in cadavers. Acta Anaesthesiol Scand 2018;62:1001-6.
6Short AJ, Barnett JJ, Gofeld M, Baig E, Lam K, Agur AM, et al. Anatomic study of innervation of the anterior hip capsule: Implication for image-guided intervention. Reg Anesth Pain Med 2018;43:186-92.
7Orozco S, Muñoz D, Jaramillo S, Herrera AM. Pericapsular nerve group (PENG) block for perioperative pain control in hip arthroscopy. J Clin Anesth 2020;59:3-4.
8Mistry T, Sonawane KB, Kuppusamy E. PENG block: Points to ponder. Reg Anesth Pain Med 2019. pii: rapm-2018-100327.
9Ueshima H, Otake H. Pericapsular nerve group (PENG) block is effective for dislocation of the hip joint. J Clin Anesth 2019;52:83.
10Roy R, Agarwal G, Pradhan C, Kuanar D. Total postoperative analgesia for hip surgeries, PENG block with LFCN block. Reg Anesth Pain Med 2019. pii: rapm-2019-100454.
11Nielsen ND, Bendtsen TF. Motor-sparing regional analgesia for hip-derived pain. Reg Anesth Pain Med 2019. pii: rapm-2018-100157.
12Yu HC, Moser JJ, Chu AY, Montgomery SH, Brown N, Endersby RV. Inadvertent quadriceps weakness following the pericapsular nerve group (PENG) block. Reg Anesth Pain Med 2019;44:611-3.