Pericapsular Nerve Group (PENG) Block and Lateral Femoral Cutaneous Nerve (LFCN) Block Versus Fascia Iliaca (FIC) Block for Multimodal Analgesia After Total Hip Replacement Surgery: a Retrospective Analysis
Conditions: Regional Anesthesia Morbidity, Arthropathy of Hip, Hip Arthropathy
Sponsor: Ospedale Edoardo Bassini

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Pericapsular nerve group block (PENG) and lateral femoral 
cutaneous nerve (LFCN) block versus fascia iliaca (FIC) block for 
multimodal analgesia after total hip replacement surgery: a 
retrospective analysis. 
 
Concise title: PENG + LFCN block vs FIC block for pain management after hip replacement 
surgery: a retrospective study. 
 
Alessandro Girombelli MD1, Francesco Vetrone MD1, Francesco Saglietti MD2, Andrea Galimberti 
MD1, Andrea Fusaro MD4, Michele Umbrello MD3, Angelo Pezzi MD1. 
1 Anesthesiology and critical care medicine, Department of Surgery and Emergency, ASST Nord 
Milano, Bassini hospital, via Gorki, 50 - 20092 Cinisello Balsamo (MI) Italy. 
2 Department of Anesthesiology and critical care medicine, Azienda Ospedaliera S. Croce e Carle, 
Via Michele Coppino, 26, 12100 Cuneo (CN), Italy. 
3 Anesthesiology and critical care medicine, SC Anestesia e Rianimazione II, ASST Santi Paolo e 
Carlo – Polo Universitario, Ospedale San Carlo Borromeo, Via Pio II, 3, 20153 Milano (MI), Italy. 
4 Orthopedic surgery division, ASST Nord Milano, Ospedale Bassini, via Gorki, 50 - 20092 Cinisello 
Balsamo (MI) Italy. 
 
 
 

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Introduction 
Postoperative pain control is a cornerstone of the perioperative management for orthopedic surgery 
as it allows for a prompt mobilization and initiation of physical therapy and thus better 
perioperative outcomes 1–4. This is especially true for old and frail patients undergoing hip 
replacement surgery, where optimal pain control limits the risk of postoperative delirium, expedites 
the initiation of physical rehabilitation and grants a faster postoperative recovery 5–9. Optimal pain 
control should entail a multimodal approach comprised of acetaminophen, NSAIDs (non-steroidal 
anti-inflammatory drugs), and PRN opioids paired with spinal anesthesia and peripheral nerve 
blocks 10–13. 
Fascia iliaca compartment block (FICB) has been vastly employed for pain management for 
elective surgery of the hip as well as for pain relief for hip fractures14–17. This technique blocks the 
lateral femoral cutaneous nerve (LFCN), covering the surgical incision, and the femoral nerve but is 
unable to reach the obturator and the accessory obturator nerves, thus sparing two of the three 
nerves that innervate the hip. Furthermore, there is a chance of quadriceps muscle weakness since 
the local anesthetic reaches the femoral nerve18. Regardless, this is the currently recommended nerve 
block for hip surgery 2. 
The pericapsular nerve group (PENG) block is a novel block for hip surgery and pain management 
in hip fractures that is slowly gaining popularity19. This technique blocks all three nerves that 
innervate the anterior aspect of the hip with a single injection. This block yields excellent pain 
control with an extremely low incidence of motor block when compared to FICB20–24. This approach 
is unable to manage the pain from the surgical incision since it spares the LFCN. For this reason, 
adding the LFCN block to the PENG block has been proposed26-27 The studies comparing PENG to 
FICB are limited and burdened by significant heterogeneity (i.e. type, volume and concentration of 
local anesthetic, choice of general vs spinal anesthesia, etc.). The combination of PENG plus LFCN 
block is a relatively new approach with only a small number of case series and case reports 
available in the literature 27–30. No study comparing PENG plus LFCN block with FICB was found.  
 
The aim of the current investigation was to determine which of these two blocks resulted in the 
lowest NRS score. Our hypothesis is that PENG plus LFCN block offers better pain management 
with the lowest risk of motor block and possibly lower PRN opioid consumption compared to 
FICB. 
Methods 
Study design 
This single-center, retrospective investigation was conducted at ASST Nord Milano Bassini 
hospital. The study was approved by the ethics committee “Comitato Etico Milano Area 3”. 
Because of the retrospective nature of the study and since no patient follow-up was performed, the 
requirement for written informed consent was waived by the ethics committee. The main outcome 
of the study was the comparison of postoperative pain at 6, 12 and 24 h, expressed as NRS (numeric 
rating scale), between PENG and LCFN . Secondary outcomes included total opioid consumption 
expressed as milligrams of morphine equivalents (MME), time to first opioid request, time to first 
postoperative ambulation.  
The study population was obtained from the hospital’s operating room digital charting program 
using the ICD code “primary hip arthritis” and “total hip replacement surgery” from April 2022 to 
November 2022. The inclusion criteria were: elective total hip replacement surgery for non-
traumatic hip disease, age >18 years, complete clinical chart included the type of peripheral nerve 
block performed, signed consent form for spinal anesthesia and peripheral nerve block. The 
exclusion criteria were: incomplete chart, a peripheral nerve block other than PENG or FICB was 

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performed. Age, sex, weight, height, BMI, ASA clinical status, type of peripheral block, NRS score 
respectively at 6-12-24 hours post operatively, time to first PRN opioid request, total PRN opioid 
dose, time to first postoperative ambulation, adverse events such as nausea, vomiting and 
hypotension if reported were obtained from the clinical chart and digitally recorded on a Excel 
spreadsheet (Microsoft Office, Redmond, USA).  
All patients underwent surgery with the anterior approach technique to hip replacement. Spinal 
anesthesia was performed with 0.5% hyperbaric bupivacaine 0.05mg/height in cm plus intrathecal 
sufentanyl 5mcg, peripheral nerve block was performed prior to surgical incision. Both blocks were 
performed under ultrasound guidance (Ecube i7, Alpinion, Biolive group,Seoul, South Korea). 
FICB was performed using a linear ultrasound probe (7.5-12 MHz) and a 50mm ultrasound 
compatible needle. 20ml of 0.5% ropivacaine were injected and proper local anesthetic spread was 
confirmed with ultrasound. PENG plus LFCN block was performed with a curvilinear probe (2-5 
MHz) with a 80mm ultrasound compatible needle. 20ml of 0.5% ropivacaine were injected for 
PENG and 10ml of 0.5% ropivacaine for LFCN. Proper spread of local anesthetic was confirmed 
with ultrasound. 
All patients received 1g acetaminophen every 8h (i.v. intraoperatively then p.o.), NSAIDs (non-
steroidal anti-inflammatory drugs), namely ibuprofen 400mg every 8h (i.v. intraoperatively then 
p.o.) and PRN opioid if NRS >5, targeting an initial dose of maximum 30 MME, in accordance with 
the recent guidelines on opioid prescription for opioid naïve patients31. For those patients already 
receiving opioids for subacute or chronic pain, PRN opioids are still prescribed and tapered 
according to the intensity of postoperative pain while maintaining the initial opioid prescription31. 
 
Statistical analysis 
Categorical variables were expressed as absolute frequencies (n) and percentages (%) while 
continuous variables were reported as median and interquartile range (IQR, with 25° e 75° 
percentile) given the limited number of observations. Data analysis was conducted with STATA 
14.0 (StataCorp LLC, College Station, TEXAS, USA). 
The following statistical tests were chosen:  
 
Fisher’s exact test for categorical variables 
 
Student’s t test, or its non-parametric analogue the Two-sample Wilcoxon rank-sum test 
where used for continuous variables, based on the distribution of the variables 
 
Two way ANOVA for repeated measurements, for the comparison between the different 
variables in the two cohorts at different time points. The type of peripheral block (inter-
subject variable) and time (intra-subject variable) were considered independent categorical 
variables. The interaction between the type of block and time (combined time and group 
effect) were also included in the model. The statistical significance of the intra-subject factor 
was corrected with the Greenhouse-Geisser method. If a statistically significant interaction 
between variables occurred then a Siegel-Tukey Test for multiple interaction was employed. 
Three p-values(p) are thus reported: P(block): group effect, to compare the different NRS 
scores between cohorts or sub-populations, P(time): time effect, to compare the NRS scores 
at different time points; P(block*time): combined effect, to take the interaction between the 
group and time effect into account.