An interventional study of PENG Block and Iliopsoas nerve block in Total Hip Arthroplasty (THA), Postoperative Pain Management and Peripheral Nerve Blocks, sponsored by University of Liege. Recruiting at 1 site in Belgium. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-06.
Sponsored by University of Liege · Not applicable, Interventional, and Treatment
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.
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.
5,640 studies on the registry are indexed under Pain, Postoperative; 1,230 are open to participants now.
This study's planned enrollment of 118 is above the median of 75 across 4,821 interventional studies indexed under Pain, Postoperative.
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Adult patients (age >18 years) 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)
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients will receive a pericapsular nerve group block with 14 ml of ropivacaine 3.75 mg/ml, administered 30 minutes prior to spinal anesthesia.
Procedure: PENG Block
Patients will receive an iliopsoas plane block with 7 ml of ropivacaine 7.5 mg/ml, administered 30 minutes prior to spinal anesthesia.
Procedure: Iliopsoas nerve block
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.
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.
Dynamic Pain 6h postoperative
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.
Time frame: 6 hours after surgery
Total Morphine Consumption
Total morphine consumption at 48 hours on Patient Controlled Intravenous Analgesia device.
Time frame: First postoperative 48 hours
NRS Dynamic pain
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.
Time frame: First postoperative 48 hours
NRS Rest pain
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.
Time frame: First postoperative 48 hours
2MWT
Distance walked in meters during 2-minute at postoperative day 1 and day 2
Time frame: First postoperative 48 hours
6MWT
Distance walked in meters during 6-minutes test at postoperative day 1 and day 2
Time frame: First postoperative 48 hours
TUG
Timed Up and Go (TUG) test results at postoperative day 1 and day 2
Time frame: First postoperative 48 hours
QoR-15
Patient recovery scores using the 15-item Quality of Recovery (QoR-15) questionnaire on postoperative days 1 and 2. Minimum: 0; Maximum: 150.
Time frame: First postoperative 48 hours
IPO
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.
Time frame: 48 hours after surgery
Morphine-related complications
Incidence of opioid-related side effects (nausea, vomiting, constipation, urinary retention, pruritus, dizziness, hypotension)
Time frame: First postoperative 48 hours
LOS
Length of hospital stay
Time frame: 48 hours after surgery
Plan to share: No — Patient data will be anonymized and collected via the REDCap platform, compliant with current data protection regulations. Only the principal investigator and authorized study personnel will have access. Data will be stored securely for 10 years.
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