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NCT Number: NCT06964282

Iliopsoas (IPB) and Pericapsular Nerve Group (PENG) Blocks Comparison on Analgesia and Recovery After Total Hip Arthroplasty

Background:

In recent years, regional anesthesia has become more popular because it can reduce pain and the need for strong pain medications like morphine. For hip surgery, the PENG block is already known to be effective. A newer method, called the iliopsoas plane block (IPB), is very similar and has also shown good results in hip arthroscopy. However, these two techniques have never been directly compared in patients undergoing hip replacement surgery using the posterior approach.

Goal:

This study aims to see if the IPB is just as effective as the PENG block for controlling pain and helping patients recover well after hip replacement surgery.

Method:

118 adult patients scheduled for hip replacement under spinal anesthesia will be randomly assigned to receive either: IPB: 7 ml of Ropivacaine 7.5 mg/ml PENG: 14 ml of Ropivacaine 3.75 mg/ml Both injections are given under ultrasound guidance 30 minutes before spinal anesthesia. Neither the patient, the surgeon, nor the data collector will know which technique was used.

Post-Surgery Care:

All patients will receive standard pain relief, including:

Paracetamol every 6 hours Etoricoxib once a day Morphine via a patient-controlled pump for 48 hours

Main Outcome Measured:

The primary goal is to compare pain during movement 6 hours after surgery, using a pain scale from 0 (no pain) to 10 (worst pain). The study will consider the two blocks equivalent if the difference in average pain scores is less than 1 point.

Other Outcomes:

Total morphine used in 48 hours Pain scores at rest and during movement at various time points Walking ability (2- and 6-minute walk tests, and timed-up-and-go test) Quality of recovery (using the QoR-15 questionnaire) Side effects of morphine Patient satisfaction Length of hospital stay

Safety:

Both techniques are safe and already used in clinical practice. Ultrasound guidance minimizes risks like nerve injury, bleeding, or infection.

Conclusion:

If the IPB is shown to be as effective as the PENG block, both can be considered reliable options for pain control and early recovery after hip replacement surgery.

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Key information

Conditions

Total Hip Arthroplasty (THA) Iliopsoas Nerve Block PENG Block Peripheral Nerve Blocks Postoperative Pain Management

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Liege University Hospital

Liège, 4000, Belgium

Location status: Recruiting

Location contact

Michele Carella, MD, PhD, ESRA-DRA

CONTACT

[email protected]

+3242843658

About this study

This study investigates the comparative effectiveness of two regional anesthesia techniques-the Pericapsular Nerve Group (PENG) block and the Iliopsoas Plane Block (IPB)-in patients undergoing total hip arthroplasty (THA) via the posterior surgical approach. While both blocks have shown promise in managing postoperative pain and minimizing opioid use, direct comparisons between them in this surgical context are lacking.

The PENG block, which targets the articular branches of the femoral, obturator, and accessory obturator nerves, has become increasingly used in anterior and lateral hip surgeries. The IPB, though more recently introduced, involves injection in a similar anatomical region and has shown good analgesic results in patients undergoing hip arthroscopy. Given their overlapping targets, these two blocks may offer comparable clinical benefits; however, this has not been validated in THA performed through a posterior approach.

To address this gap, the current randomized, double-blind equivalence trial will compare the two techniques using standardized ultrasound-guided procedures and uniform dosing of ropivacaine adjusted for volume and concentration. All patients will receive the same spinal anesthetic and postoperative analgesia regimen, minimizing confounding factors.

The primary objective is to determine whether IPB provides pain control equivalent to the PENG block during early postoperative mobilization. By assessing patient-reported pain scores, along with recovery quality and opioid use, the study aims to generate evidence that may inform anesthesia planning in joint replacement surgeries and support the integration of newer regional techniques into enhanced recovery protocols.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Adult patients (age >18 years) ASA physical status classification I-III Scheduled for elective posterior approach total hip arthroplasty (THA) under spinal anesthesia

Exclusion criteria

Pregnancy (confirmed by beta-HCG test if applicable) Known peripheral neuropathy or major neurological disease Chronic pain syndromes or long-term opioid use (>20 mg oral morphine equivalents/day) Severe hepatic or renal insufficiency Allergy to local anesthetics Major coagulopathies Vulnerable patients (e.g., minors, legally protected individuals)

Treatment and study plan

PENG block

Procedure

Also performed under ultrasound guidance with an 80 mm B-Braun X360 needle and a 3-5 MHz curved probe. The femoral nerve, femoral artery, iliopsoas muscle, and pubic ramus are identified. The needle is inserted in-plane, and 14 ml of ropivacaine 3.75 mg/ml is injected between the psoas tendon and pubic ramus.

Iliopsoas nerve block

Procedure

Performed under ultrasound guidance with a curvilinear probe (5-2 MHz). The transducer is positioned transversely below the anterior superior iliac spine (ASIS), then pivoted medially. After identifying the femoral head and acetabular rim, a 22G 80 mm needle is inserted in-plane to reach the iliopsoas plane, lateral to the iliopsoas tendon. 7 ml of ropivacaine 7.5 mg/ml is then injected.

Primary outcomes

  1. Dynamic Pain 6h postoperative

    Time frame: 6 hours after surgery

    Dynamic pain score (during mobilization) at 6 hours postoperatively, measured on a 0-10 numeric rating scale (NRS). Equivalence is defined as a mean difference of less than 1 point on the NRS.

Secondary outcomes

  1. Total Morphine Consumption

    Time frame: First postoperative 48 hours

    Total morphine consumption at 48 hours on Patient Controlled Intravenous Analgesia device.

  2. NRS Dynamic pain

    Time frame: First postoperative 48 hours

    NRS Dynamic pain score (at tight flexion) at 6 hours postoperatively, measured on a 0-10 numeric rating scale (NRS) and at 8 am, 1 pm, 6pm at postoperative day 1 and day 2. No pain: 0; Maximum pain: 10.

  3. NRS Rest pain

    Time frame: First postoperative 48 hours

    NRS Rest pain score (no mobilization) at 6 hours postoperatively, measured on a 0-10 numeric rating scale (NRS) and at 8 am, 1 pm, 6pm at postoperative day 1 and day 2. No pain: 0; Maximum pain: 10.

  4. 2MWT

    Time frame: First postoperative 48 hours

    Distance walked in meters during 2-minute at postoperative day 1 and day 2

  5. 6MWT

    Time frame: First postoperative 48 hours

    Distance walked in meters during 6-minutes test at postoperative day 1 and day 2

  6. TUG

    Time frame: First postoperative 48 hours

    Timed Up and Go (TUG) test results at postoperative day 1 and day 2

  7. QoR-15

    Time frame: First postoperative 48 hours

    Patient recovery scores using the 15-item Quality of Recovery (QoR-15) questionnaire on postoperative days 1 and 2. Minimum: 0; Maximum: 150.

  8. IPO

    Time frame: 48 hours after surgery

    Patient satisfaction using the International Pain Outcomes (IPO) questionnaire at discharge. Each question is a 0 to 10 NRS scale with 0 minimum value and 10 maximum value.

  9. Morphine-related complications

    Time frame: First postoperative 48 hours

    Incidence of opioid-related side effects (nausea, vomiting, constipation, urinary retention, pruritus, dizziness, hypotension)

  10. LOS

    Time frame: 48 hours after surgery

    Length of hospital stay

Study contacts

Contact information is provided by the study sponsor or research team.

Michele Carella, MD, PhD, ESRA-DRA

CONTACT

[email protected]

+3242843658

Sponsors and collaborators

Lead sponsor

University of Liege

Other

Collaborators

  • Centre Hospitalier Universitaire de Liege

Registry information

Official study title

Comparison Between Iliopsoas Block (IPB) and Pericapsular Nerve Group (PENG) Block on Postoperative Analgesia and Functional Recovery After Total Hip Arthroplasty Surgery: a Double-blinded Randomized Clinical Trial

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
May 9, 2025
Registry last updated
May 6, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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