The Impact or Quadratum Lumborum (QL) Block Versus Pericapsular Nerve Group (PENG) With Lateral Femoral Cutaneous (LFC) Nerve Blocks for Analgesia After Hip Arthroplasty: a Prospective, Randomized Clinical Trial
Phase: NA
Conditions: Block, Hip Replacement, Postoperative Pain
Sponsor: Medical University of South Carolina

The impact or quadratum lumborum (QL) block versus pericapsular nerve group (PENG) with lateral femoral 
cutaneous (LFC) nerve blocks for analgesia after hip arthroplasty: a prospective, randomized clinical trial. 
NCT05710107 
February 2023

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PROTOCOL TITLE: 
The impact of quadratum lumborum (QL) block versus pericapsular nerve group (PENG) with lateral 
femoral cutaneous (LFC) nerve blocks for analgesia after hip arthroplasty: a prospective, randomized 
clinical trial. 
PRINCIPAL INVESTIGATOR:  Ellen Hay, M.D. 

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1.0 
Objectives / Specific Aims 
• 
Purpose: Evaluate difference in postoperative opiate consumption in patients 
receiving a lateral quadratum lumborum (QL) block versus pericapsular nerve group 
(PENG) with lateral femoral cutaneous (LFC) nerve block for analgesia after hip 
arthroplasty. 
• 
Hypothesis: The combination of PENG and LFC blocks will provide superior 
analgesia to the lateral QL block.  
2.0 
Background 
The quadratus lumborum block is a fascial plane block. Originally described for abdominal 
surgery, numerous publications have highlighted the effectiveness of quadratus lumborum 
blocks as an analgesic technique for hip fracture and hip arthroplasty [1-4]. The pericapsular 
nerve group (PENG) block has been more recently described [5,6] and has demonstrated 
improved analgesia versus no block [7], and similar analgesia with improved motor function 
versus fascia iliaca block [8] or femoral nerve block [9]. The PENG block is commonly 
combined with a lateral femoral cutaneous (LFC) nerve block for coverage of the lateral 
thigh incision.  
3.0 
Intervention to be studied 
• 
The lateral QL, PENG, and LFC blocks are already performed daily at MUSC as part 
of our standard perioperative care for patients undergoing hip arthroplasty. Currently, 
selection of the block type is dependent on the team caring for the patient that day, 
and studies have not compared QL and PENG+LFC blocks for postoperative 
analgesia after hip arthroplasty.  
• 
QL blocks: The lateral QL block is performed by injecting local anesthetic deep to 
the transversus abdominus aponeurosis and superficial to the fascia transversalis with 
direct ultrasound guidance. After completing consent, placing monitors and 
providing mild sedation, the patient is positioned laterally and the muscular anatomy 
(external oblique, internal oblique, transverse abdominis, quadratus lumborum and 
latissimus dorsi muscles) identified.  After placing a subcutaneous skin wheel with 
lidocaine, a blunt regional anesthesia needle is inserted using in-plane ultrasound 
guidance. Local anesthetic is deposited incrementally with frequent aspiration in the 
anterolateral border of the quadratus lumborum muscle at the junction of the 
transversalis fascia, outside the anterior layer of the thoracolumbar fascia and 
superficial to the fascia transversalis.  
• 
PENG block: The pericapsular nerve group (PENG) block is an ultrasound‐guided 
approach, first described by Giron‐Arango et al. for the blockade of the articular 
branches of the femoral, obturator and accessory obturator nerves that provide 
sensory innervation to the anterior hip capsule [5,6]. In the PENG block, a low-
frequency, curvilinear probe is used to visualize the anterior inferior iliac spine, 
iliopsoas tendon, and iliopubic eminence. After placing a subcutaneous skin wheel 
with lidocaine, a blunt regional anesthesia needle is inserted using in-plane 
ultrasound guidance. The needle is advanced until the tip lies on the lateral and 
inferior margin of the iliopsoas tendon between the anterior inferior iliac spine 
(lateral) and iliopubic eminence (deep).  
• 
Risks: Risks of both blocks are similar. In general, all blocks have the risks of 
infection, bleeding, or local anesthetic toxicity (LAST). Infection risk is minimized 

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by utilizing appropriate antiseptic and sterile technique as is standard for any regional 
procedure. The risk of LAST is a risk with any regional procedure and is minimized 
by frequent aspiration, incremental local anesthetic injection and vital signs 
monitoring throughout. As for any truncal block, the QL block also has the risk of 
bowel perforation as it is higher in the abdominal wall.  This risk is minimized with 
real time US visualization. The PENG block is located closer to the femoral nerve, 
and local anesthetic could spread to the femoral nerve with medial or superficial 
injection.  
• 
Current practice: Both QL and PENG blocks are utilized at MUSC daily for 
postoperative pain following hip arthroscopy, arthroplasty, and hip fracture.  Our 
current practice in patients receiving a PENG block includes also blocking the lateral 
femoral cutaneous (LFC) nerve for coverage of the lateral thigh incision.  
• 
We hypothesize that PENG+LFC blocks will reduce opioid consumption following 
hip arthroplasty compared with lateral QL blocks.  
 
4.0 
Study Endpoints 
• 
The primary outcome will be postoperative cumulative opioid consumption (in IV 
morphine mg equivalents: IV MME) over time, up to 72 hours postoperatively.  
Cumulative opioid consumption will be evaluated at in PACU, and through 72 hours 
post-op. 
• 
Secondary outcomes: Postoperative pain score measures on the visual analog scale 
(VAS) captured in the preoperative area, PACU, and through 72-hours post-op.   
• 
Additional outcomes of interest include time to first ambulation, functional and 
mobility outcomes, PACU duration, patient satisfaction, and opioid related side 
effects.  
 
5.0 
Inclusion and Exclusion Criteria/ Study Population 
Inclusion Criteria  
• 
Age greater than or equal to 18 years old 
• 
Ambulatory patients undergoing elective hip arthroplasty (planned same day 
discharge or observation 23 hours or less) 
Exclusion Criteria 
• 
Local anesthetic allergy 
• 
Subjects with a weight less than 40kg 
• 
Subjects that are unable or choose not to give informed consent 
• 
Known preoperative substance abuse 
 
6.0 
Number of Subjects 
A total of 106 subjects will be included. 
7.0 
Setting 

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• 
MUSC perioperative areas. 
 
8.0 
Recruitment Methods 
• 
For patients presenting to a preoperative clinic visit, information regarding the study 
will be presented to subject during their surgical consultation in the form of a flyer 
and informed consent document. Subjects will be educated on the role of regional 
anesthesia in postoperative analgesia. Subjects will be given ample time to consider 
participating in the surgery and asking questions. On the day of surgery, subjects may 
then choose to provide written consent or decline to participate. For patients without 
a surgical consult, the study will be presented on the day of surgery and will be given 
enough time to read the consent and consider participation.  
• Subjects will be enrolled on the day of surgery in the preoperative holding area.   
9.0 
Consent Process 
After discussion in a private area in the preoperative holding area regarding risks and 
benefits of the study and both block techniques, patients will be given adequate time to 
read the consent, think about participating, and ask questions. If agreeable to 
participating, consent will be obtained from patient by an IRB approved CITI certified 
study team member who is a physician or other medical clinician and has been trained 
on the protocol. Written consent will be completed once all questions are answered 
and inclusion and exclusion criteria verified. Copies of all documents will be provided 
to the patient. Once patients are consented, they will be assigned a study ID. 
Randomization group (quadratus lumborum block versus pericapsular nerve group 
with lateral femoral cutaneous nerve blocks) will be determined by a randomization 
list created by a statistician and assigned based on the subject’s study ID.  
 
10.0 Study Design / Methods 
• Objective and outcomes: Determine if PENG+LFC blocks reduce opioid consumption 
compared to a QL block after THA.  
• Design:  This prospective, blinded clinical trial will randomize subject to receive a 
PENG+LFC or QL block prior to THA.   The randomization will be created by a 
statistician prior to subject enrollment.  
• Groups: Subjects will be randomized to receive a preoperative PENG+LFC (n=53) or 
QL (n = 53) block prior to THA. 
• Potential participants that are on the operating room schedule for THA will be screened 
for eligibility via chart review. 
 
Baseline 
• Once subjects have signed an informed consent, they will be assigned an enrollment 
number.  Randomization will be created prior to the study starting with half of the 
research subject numbers being assigned to receive a PENG+LFC block, and the other 
half assigned to receive a QL block. Both blocks are considered our current standard of 
care. A study team member will open the envelope labeled with the subject’s assigned 
study ID to reveal the randomization assignment. 

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• The participant’s medical record will be reviewed for demographic data collection and 
durations (operative, PACU, hospital stay).   
• Before placing the block, participants will be asked what their current pain score is by 
using a Visual Analog Scale (VAS) from 0-100, and complete the HOOS Jr, and 
PROMIS-10 Global Health questionnaires.  
 
Randomization 
• All subjects will be positioned, prepped, and sedated for the randomized regional 
anesthesia procedure in the preoperative holding area. The subject will be positioned in 
the supine position and pulse oximetry and blood pressure cuff placed for monitoring.  
As part of routine care, the subject will receive sedation for their comfort. All subjects 
would receive 30 ml of 0.25% ropivacaine in their nerve block regardless of 
randomization.  The relevant anatomy will then be identified using ultrasound guidance 
and real time imaging.  For both groups, ropivacaine will be injected slowly with 
frequent aspiration to rule out inadvertent intravascular needle placement. Local 
anesthetic injection will also be observed with real time ultrasound guidance. All 
participants, regardless of group assignment, will have subcutaneous numbing 
medication placed just below the skin at both block sites (skin wheal). This will be 
done so that participants and the research team collecting results will be 
blinded.  Subjects, surgeons, and data collectors will all be blinded to the allocated 
group. Unblinded personnel will be the Anesthesia Attending placing the block and 
clinical staff assisting.  
• In subjects randomized to the QL group, ultrasonography will be used 
to identify external oblique, internal oblique, transverse abdominus, and quadratus 
lumborum muscles. A needle will then be advanced under ultrasound guidance below 
the internal oblique aponeurosis and lateral to the quadratus lumborum 
muscle.  Ropivacaine will be injected slowly with frequent aspiration to rule out 
inadvertent intravascular needle placement. Local anesthetic injection will also be 
observed with real time ultrasound guidance. 
• In subjects randomized to the PENG+LFC group, ultrasonography will be used 
to identify the anterior inferior iliac spine, iliopsoas tendon, and iliopubic eminence. 
After placing a subcutaneous skin wheel with lidocaine, a needle will be advanced until 
the tip lies on the lateral and inferior margin of the iliopsoas tendon between the 
anterior inferior iliac spine (lateral) and iliopubic eminence (deep). 
 
Post-Op and Follow-Up 
The participant will be asked to provide their average pain score while at rest, and 
average pain score with movement in the specified time period using a visual analog 
scale from 0-100 with 100 being the worst. The first pain score will be recorded before 
they leave the PACU on the day of the procedure. Beginning the following morning, 
the participant will receive a text message link sent by Twilio’s secure server that 
opens a survey housed in RedCap. The first text message will arrive at 9:00 AM and 
will follow the schedule in Table 1.   
 
The follow-up text messages will also ask the patient the name, dose, and frequency of 
any pain medication taken in that time period. On Day 7, the text message survey will 
assess functional outcomes by using two different questionnaires. The patient will 
schedule at least two post-operative in-person follow up visits as standard of care. One 
visit at approximately 2-3 weeks post-op, and the other at approximately 6 weeks. 

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During these two visits the patient will complete the same functional questionnaires as 
they did at Baseline and on Day 7. This may be done in person at their standard of care 
post-op visits or may be contacted by study personnel to complete via telephone.  
Adverse events will also be collected throughout the study.   
 
The text messages are sent from a secure server, Twilio, and are housed in REDCap. 
The set of questions will state what time window (example: 12:00 AM midnight the 
night prior to 12:00 PM noon the same day) to consider when answering the questions.  
 
If the participant has been discharged from the hospital, they will answer these 
questions in the text message each day. If they are admitted to the hospital at these 
points in time, the information will be gathered from their chart for medications and 
asked verbally for pain scores and additional questions. Additional data will be 
recorded by physical therapy and surgical staff and pulled from the patient’s medical 
record for data collection.  
 
If the participant is unable or unwilling to receive text messages, they will be provided 
a paper document to record their data for the pre-determined intervals so when a study 
member contacts them, they are able to relay their answers back accurately. 
 
Care in the perioperative period will otherwise be standardized.  In the post-anesthesia 
care unit (PACU), hydromorphone or morphine will be titrated by the PACU nurse for 
the subject’s comfort.  Additionally, as standard of care, Physical Therapy will evaluate 
patients in the PACU before discharge. 
An outline of study time points and assessments is shown in Table 2. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Table 1. Post-Op Follow Up Assessment Schedule 
Post-Op Day 
Time of Text Message 
Data Collection Time Period 
POD 0 
Right before discharge 
Waking up from surgery to discharge 
POD 1-AM 
9:00 AM 
Discharge to 11:59 midnight prior 
POD 1-PM 
3:00 PM 
12:00 AM midnight night prior to 12:00 PM noon 
same day 
POD 2-AM 
9:00 AM 
12:01 PM noon day prior to 11:59 PM midnight 
night prior 
POD 2-PM 
3:00 PM 
12:00 AM midnight prior to 12:00 PM noon same 
day 
POD 3-AM 
9:00 AM 
12:01 PM noon day prior to 11:59 PM midnight 
night prior 
POD 3-PM 
3:00 PM 
12:00 AM midnight prior to 12:00 PM noon same 
day 

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Table 2. Summary of Study Procedures and Follow-Ups 
Study Activities 
Details/Assessments 
Informed consent 
• 
Obtain informed consent 
Baseline 
• 
Pre-Operative VAS Pain Score 
• 
Quad Strength Pre-Op 
• 
HOOS Jr 
• 
PROMIS-10 Global Health 
Randomization (day 0) 
• 
Confirm eligibility criteria 
• 
Randomization 
Randomization procedure (day 0) 
• 
Complete PENG or QL Block according to randomization 
allocation 
Post-Op First Opportunity in PACU 
• 
Opioid Consumption 
Ambulation (Assessed by Physical Therapy in PACU) 
• 
Time that first ambulation occurred in PACU  
• 
Distance ambulated in PACU 
• 
Quad Strength in PACU 
Post-Op Day 1 9:00 AM (text message) 
• 
Opioid and pain medication consumption 
• 
VAS Pain Score 
Post-Op Day 1 3:00 PM  (text message) 
• 
Opioid and pain medication consumption 
• 
VAS Pain Score 
Post-Op Day 2 9:00 AM(text message) 
• 
Opioid and pain medication consumption 
• 
VAS Pain Score 
Post-Op Day 2 3:00 PM (text message) 
• 
Opioid and pain medication consumption 
• 
VAS Pain Score 
Post-Op Day 3 9:00 AM (text message) 
• 
Opioid and pain medication consumption 
• 
VAS Pain Score 
Post-Op Day 3 3:00 PM  (text message) 
• 
Opioid and pain medication consumption 
• 
VAS Pain Score 
• 
Satisfaction with analgesia 
• 
Side Effects of nausea/vomiting, itching, over sedation, 
respiratory concerns related to opioids 
• 
Adverse Events 
Day 7 Post-Op 9:00 AM (text message) 
• 
HOOS JR 
• 
PROMIS-10 Global 
• 
Adverse Events 
Week 2-3 Post-Op  
(scheduled SOC clinic visit or telephone) 
• 
HOOS JR 
• 
PROMIS-10 Global 
• 
Adverse Events 
Week 6 Post-Op  
(scheduled SOSC clinic visit or telephone) 
• 
HOOS JR 
• 
PROMIS-10 Global 
• 
Averse Events 
After completion of 6-week post-op follow-up 
• 
All study activities complete 

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11.0 Data Management  
• 
Sample size and power: The primary outcome for assessing differences between 
PENG+LFC vs. QL blocks will be postoperative cumulative opioid consumption (in 
IV morphine mg equivalents; IV MME) over time, up to 72 hours postoperatively.  
Cumulative opioid consumption will be evaluated in PACU, and at 12-hour intervals 
during the first 72 hours of the postoperative window.  Differences in cumulative 
opioid consumption over time between block groups will be assessed using a linear 
mixed model approach.  The model will include fixed effects for treatment group, 
postoperative time, and the interaction between block group and postoperative time 
and a random subject effect to account for correlation between measures collected on 
the same patient over time.  Differences between block types at each postoperative 
time will be evaluated using linear contrasts from the model.  A previous study9 
conducted at MUSC found mean IV MME at 12 hours postop in subjects undergoing 
THA with a QL block was 16 ± 12 MME.  A sample size of 48 subjects per group 
with 9 repeated measures of opioid consumption provides 80% power to detect a 
difference in cumulative MMEs consumed postoperatively of 4 MMEs at significance 
level α = 0.006 (Bonferroni adjusted for 9 pairwise comparisons between group) 
assuming a standard deviation of ± 12 MMEs, a first-order autoregressive correlation 
structure and correlation between observations on the same subject of ρ = 0.33. We 
will plan to enroll 53 subjects/group (106 total) to allow for 10% attrition. 
• 
Postoperative VAS pain score captured in the preoperative area, PACU and 12-hour 
intervals during the first 72 hours of the postoperative window will be collected as a 
secondary outcome and will be evaluated using a LMM similar to the primary 
outcome.  Additional outcomes of interest include time to first ambulation, functional 
and mobility outcomes, PACU duration, patient satisfaction, and opioid related side 
effects.     
12.0 Provisions to Monitor the Data to Ensure the Safety of Subjects  
• 
All new complaints and symptoms (i.e., those not existing prior to signing of informed 
consent) will be recorded on the AE CRF. All AEs will be characterized in terms of 
their start and stop dates, intensity, action taken, relationship to intervention, subject 
outcome, and whether or not the AE led to an SAE.   
• 
Any adverse events related to placement of nerve blocks will be treated according to 
MUSC Hospital policy and procedures and the practice of the Department of 
Anesthesia.   
• 
The Department of Anesthesia’s DSMB will review the study on an annual basis. Any 
adverse events will be reported and reviewed by the DSMB. Adverse events will be 
reported to MUSC’s IRB per policy. 
• 
All data will be kept in a locked office, in a locked cabinet, and electronic data will be 
stored on a password protected MUSC server. Only CITI certified, IRB approved 
study team members will have access to data.  
 
13.0 Withdrawal of Subjects  
• 
The participant has the right to voluntarily withdraw consent from the study at any 
time for any reason without prejudice to his/her future medical care by the physician 
or at the institution. For the occasional participant who withdraws consent, the date 
and reason for consent withdraw should be documented. Participant data will be 
included in the analysis up to the date of the consent withdraw.  

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• 
Investigators may stop a subject’s participation in the study at any time if they 
decide it is in the subject’s best interest. They may also do this if the subject does 
not follow the investigator’s instructions.  
 
14.0 Risks to Subjects 
• 
PENG+LFC Block: risks include infection, bleeding, local anesthetic systemic 
toxicity (LAST), nerve damage, block failure, and quadricep weakness. Infection 
risk is minimized by utilizing appropriate antiseptic and sterile technique as is 
standard for any regional procedure. The risk of LAST is a risk with any regional 
procedure and is minimized by frequent aspiration, incremental local anesthetic 
injection, and vital sign monitoring throughout.  
• 
QL Block: risks include infection, bleeding, local anesthetic systemic toxicity 
(LAST), nerve damage, block failure, and quadricep weakness. Infection risk is 
minimized by utilizing appropriate antiseptic and sterile technique as is standard for 
any regional procedure. The risk of LAST is a risk with any regional procedure and 
is minimized by frequent aspiration, incremental local anesthetic injection, and vital 
sign monitoring throughout. There is also a risk of quadricep weakness. 
• 
Subjects will be randomly assigned to receive either 1) PENG + LFC or 2) QL 
block. One group may prove to be less beneficial than the other. 
• 
There is also a risk of loss of confidentiality. 
 
15.0 Potential Benefits to Subjects or Others 
• 
The PENG+LFC target analgesia for directly to the hip capsule compared with the 
QL blocks and may improve targeted analgesia without compromising motor 
function of the operative extremity and promoting earlier postoperative physical 
therapy.  
16.0 Sharing of Results with Subjects 
Prior to starting the investigation, the trial will be registered at clinicaltrials.gov. Results 
will be posted after the study is completed.  
 
17.0 Drugs or Devices  
• 
All medications are FDA approved.  All nerve block procedures are already 
performed daily at MUSC. The block medication will be managed and dispensed by 
the OR pharmacy.  
 
References 
 
1. Kelly T, Wolla CD, Wolf BJ, et al.  Comparison of lateral quadratus lumborum and lumbar 
plexus blocks for postoperative analgesia following total hip arthroplasty: a randomized clinical 
trial.  Regional Anesthesia & Pain Medicine 2022;47:541-546. 

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2. Ueshima H, Yoshiyama S, Otake H. The ultrasound-guided continuous transmuscular quadratus 
lumborum block is an effective analgesia for total hip arthroplasty. J Clin Anesth 2016;31:35. 
3. Johnston DF, Sondekoppam RV. Continuous quadratus lumborum block analgesia for total hip 
arthroplasty revision. J Clin Anesth 2016;35:235–7. 
 
4. McCrum CL, Ben-David B, Shin JJ, et al. Quadratus lumborum block provides improved 
immediate postoperative analgesia and decreased opioid use compared with a multimodal pain 
regimen following hip arthroscopy. J Hip Preserv Surg 2018;5:233–9. 
 
5. Girón‐Arango L, Peng PWH, Chin KJ, Brull R, Perlas A. Pericapsular Nerve Group (PENG) 
block for hip fracture. Regional Anesthesia and Pain Medicine 2018; 43: 859–63.  
 
6. Del Buono R, Padua E, Pascarella G, et al. Pericapsular Nerve Group (PENG) block: an 
overview. Minerva Anestesiologica 2021; 87: 458–66 
 
7. Pascarella G, Costa F, Del Buono R, Pulitanò R, Strumia A, Piliego C, De Quattro E, Cataldo R, 
Agrò FE, Carassiti M; collaborators. Impact of the pericapsular nerve group (PENG) block on 
postoperative analgesia and functional recovery following total hip arthroplasty: a randomised, 
observer-masked, controlled trial. Anaesthesia 2021 Nov;76(11):1492-1498. 
 
8. Aliste J, Layera S, Bravo D, Jara Á, Muñoz G, Barrientos C, Wulf R, Brañez J, Finlayson RJ, 
Tran Q. Randomized comparison between pericapsular nerve group (PENG) block and 
suprainguinal fascia iliaca block for total hip arthroplasty. Reg Anesth Pain Med. 2021 
Oct;46(10):874-878. 
 
9. Lin DY, Morrison C, Brown B, Saies AA, Pawar R, Vermeulen M, Anderson SR, Lee TS, 
Doornberg J, Kroon HM, Jaarsma RL. Pericapsular nerve group (PENG) block provides improved 
short-term analgesia compared with the femoral nerve block in hip fracture surgery: a single-center 
double-blinded randomized comparative trial. Reg Anesth Pain Med. 2021 May;46(5):398-403.