Investigating the Effect of Pericapsular Nerve Group (PENG) Block on Postoperative Pain After Peri-acetabular Osteotomy

A Blinded Randomized Study Investigating the Effect of Pericapsular Nerve Group (PENG) Block on Postoperative Pain After Peri-acetabular Osteotomy

The aim of this study is to determine the effect of PENG blockade on postoperative pain after either ropivacaine 5 mg/mL or saline (placebo) in patients undergoing PAO. The hypothesis of this study is that PENG block with ropivacaine reduces postoperative pain compared to placebo (saline).

Study Overview

• Status: Recruiting
• Conditions: Anesthesia, Local
• Intervention / Treatment: Drug: Ropivacaine 5mg/ml 20ml; Drug: Saline 0.9%

Detailed Description

Peri-acetabular osteotomy (PAO) is the joint-preserving treatment of choice in young adults with symptomatic hip dysplasia. However, moderate to severe pain occurs frequently in the postoperative period. Pain after PAO comes primarily from the anterior hip capsule which is innervated by the terminal nerves of the lumbar plexus comprising branches from the femoral, obturator and accessory obturator nerves. The articular branches from the femoral nerve reach the plane between the iliopsoas muscle and the iliofemoral ligament (iliopsoas plane) and innervate the anterior and lateral aspects of the hip capsule. The articular branches innervate the anterior and medial aspects of the hip capsule and the accessory obturator nerve contributes to the innervation of the hip in 10%-30% of the patients, and supplies the inferomedial aspect of the hip capsule. The PAO procedure, involving three osteotomies in otherwise healthy individuals, is likely to produce a substantial surgical stress response, which potentially could be alleviated by multimodal analgesia including the pericapsular nerve group (PENG) block.

The PENG block is a novel regional anaesthesia technique that has been proposed as an effective motor-sparing block for total hip arthroplasty. The PENG block targets the articular branches providing innervation to the anterior capsule of the hip joint, including the femoral, obturator and accessory obturator nerves. Its potential analgesic and motor-sparing effect is desirable for early ambulation, better physical therapy, and earlier discharge.

Conventional opioid-sparing regional anaesthetic techniques such as lumbar plexus and femoral nerve blocks are effective but carry a risk of undesirable lower limb muscle weakness. Alternatively, the fascia iliaca block does not consistently provide adequate pain relief for hip surgeries.

The anterior capsule of the hip has a high density of nociceptors and mechanoreceptors and appears to be the primary source of pain after hip surgery. The PENG block targets the articular branches providing innervation to the anterior capsule of the hip joint, including the femoral, obturator and accessory obturator nerves.

A recent study reported improved quality of recovery and reduced opioid requirements for patients undergoing primary THA whereas other studies have reported conflicting results regarding the analgesic efficacy for THA. However, the effect of PENG on PAO has not been investigated.

Thus, in order to investigate if PENG block is superior to placebo in decreasing immediate pain and other complications after PAO, the investigators aim to conduct a randomised, double-blinded trial of ropivacaine 5 mg/ml vs. placebo. The investigators hypothesize that patients given ropivacaine 5 mg/ml will have less pain in the first 24 postoperative hours compared with patients given placebo.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Matias Vested; Phone Number: +4535455747; Email: matias.vested@regionh.dk

Study Locations

• Denmark
  • Copenhagen, Denmark, 2100
    • Recruiting
    • Rigshospitalet
    • Contact: Matias Vested; Phone Number: +4535455747; Email: matias.vested@regionh.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Patients ≥ 18 years old
2. Informed consent
3. Scheduled for periacetabular osteotomy under general anesthesia with intubation
4. American Society of Anesthesiologists (ASA) physical status classification I to III
5. Can read and understand Danish

Exclusion Criteria:

1. Known allergy to ropivacaine
2. Daily use of opioids, gabapentin or tricyclic antidepressant (regardless of dose) within the last four weeks prior to surgery
3. Contraindications to Celocoxib, NSAIDs or paracetamol

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ropivacaine group; Ropivacaine 5 mg/ml 20ml	Drug: Ropivacaine 5mg/ml 20ml; administered in a pericapsular nerve group (PENG) block
Placebo Comparator: Saline group; NaCl 0.9%	Drug: Saline 0.9%; administered in a pericapsular nerve group (PENG) block

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain during first 24 hours postoperatively	Area under curve (AUC) of pain reported on a numeric rating scale (NRS) from 0 to 10 (where 0 is no pain and 10 is the worst pain imaginable) during the first 24 hours postoperatively	24 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Presence of moderate to severe pain	The number of patients reporting moderate to severe pain at rest [>3 out of 10 on a numeric rating scale (NRS) from 0 to 10 (where 0 is no pain and 10 is the worst pain imaginable)] at any point in the immediate postoperative phase (from arrival at the PACU until transfer to the ward). NRS will be assessed upon arrival at the PACU and each 30 minutes.	within 3 hours
Pain during mobilization	Pain during during mobilization (from laying down in bed till standing on the floor) assessed on numeric rating scale (NRS) from 0 to 10 (where 0 is no pain and 10 is the worst pain imaginable) at 5 hours after extubation	within 5 hours
Opioid use 24 hours	Opioid use from tracheal extubation until 24 hours postoperatively	24 hours
Pain during mobilization	Pain during during mobilization (from laying down in bed till standing on the floor) assessed on numeric rating scale (NRS) from 0 to 10 (where 0 is no pain and 10 is the worst pain imaginable) at: postoperative day one between 8 and 10 pm; 24 hours after extubation	within 24 hours
First opioid	Time to first opioid	within 24 hours
Last opioid	Time to last opioid	within a week
Time to first PONV-medication	Time to first PONV-medication	within 24 hours
Opioid use at PACU	Opioid use at PACU	within 24 hours
Sleep quality/pain during sleep.	During the first postoperative night the patients answer yes/no to whether they awoke from their sleep because of pain.	within 24 hours
Length of stay at hospital	Length of stay at hospital	within a week
Length of time to fulfilling PACU discharge criteria	Length of time to fulfilling PACU discharge criteria	within 24 hours
Defecation	Time to first defecation	within 24 hours

Collaborators and Investigators

• Sponsor: Matias Vested
• Investigators: Study Chair: Matias Vested, MD, PhD, Rigshospitalet University of Copenhagen

Study record dates

Study Major Dates

• Study Start (Actual): August 19, 2024
• Primary Completion (Estimated): February 1, 2026
• Study Completion (Estimated): March 1, 2026

Study Registration Dates

• First Submitted: April 30, 2024
• First Submitted That Met QC Criteria: May 6, 2024
• First Posted (Actual): May 9, 2024

Study Record Updates

• Last Update Posted (Estimated): August 26, 2025
• Last Update Submitted That Met QC Criteria: August 19, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Pain; Neurologic Manifestations; Pain, Postoperative; Organic Chemicals; Pharmaceutical Preparations; Anilides; Amides; Aniline Compounds; Amines; Crystalloid Solutions; Isotonic Solutions; Solutions; Ropivacaine; Saline Solution
• Other Study ID Numbers: PENG for PAO

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No