This randomized, double-blinded, controlled clinical trial compares three motor-sparing regional anesthesia techniques used for postoperative analgesia in patients undergoing hip arthroplasty: the Pericapsular Nerve Group (PENG) block, the suprainguinal Fascia Iliaca Compartment Block (S-FICB), and the Lumbar Erector Spinae Plane Block (L-ESPB). Although all three techniques are widely used in modern hip surgery, their relative analgesic efficacy, opioid-sparing potential, and impact on early functional recovery have not been directly compared in a single study. The primary objective is to determine which block provides the most effective postoperative analgesia while preserving motor function and facilitating early mobilization. Secondary objectives include comparisons of opioid consumption, pain scores at rest and during movement, time to first rescue analgesia, block-related adverse events, quadriceps strength, incidence of postoperative nausea and vomiting, and early functional outcomes. This study aims to identify the optimal motor-sparing regional anesthesia strategy for older adults undergoing hip arthroplasty.
Regional anesthesia plays a key role in modern multimodal analgesia for hip arthroplasty, particularly in older adults who are vulnerable to opioid-related adverse effects and postoperative functional decline. Several motor-sparing nerve block techniques have been developed to improve postoperative pain control while maintaining quadriceps strength and enabling early mobilization. Among them, the Pericapsular Nerve Group (PENG) block, the suprainguinal Fascia Iliaca Compartment Block (S-FICB), and the Lumbar Erector Spinae Plane Block (L-ESPB) are widely used in clinical practice. However, no randomized clinical trial has directly compared these three approaches within a single study population. The PENG block targets the articular branches of the femoral, obturator, and accessory obturator nerves, providing selective analgesia of the anterior hip capsule with minimal motor involvement. The suprainguinal FICB delivers a higher spread of local anesthetic over the femoral nerve, lateral femoral cutaneous nerve, and variable portions of the obturator nerve, offering broader sensory coverage but with a higher likelihood of quadriceps weakness. The lumbar ESPB is a posterior fascial plane block that may achieve indirect spread toward the lumbar plexus, potentially providing balanced anterior and posterior capsular analgesia while preserving motor function. This randomized, double-blinded, three-arm controlled trial aims to compare the analgesic effectiveness, opioid-sparing properties, and motor-sparing characteristics of PENG, S-FICB, and L-ESPB in patients undergoing hip arthroplasty. All participants will receive standardized spinal anesthesia and multimodal postoperative analgesia. The study's primary endpoint is the time to first rescue opioid administration. Secondary outcomes include total postoperative opioid consumption, pain scores at rest and during movement, quadriceps muscle strength, block performance time, incidence of postoperative nausea and vomiting, early mobilization parameters, and block-related adverse events. The results of this trial are expected to clarify the relative benefits and limitations of the three most commonly used motor-sparing regional anesthesia techniques for hip surgery and to guide optimal selection of blocks for enhanced recovery pathways in older adults undergoing hip arthroplasty.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
93
The Pericapsular Nerve Group (PENG) block will be performed under ultrasound guidance using a curvilinear or linear transducer. A 22-gauge echogenic needle will be advanced in-plane toward the fascial plane between the iliopsoas tendon and the pelvic brim at the level of the anterior inferior iliac spine. A total of 20 mL of 0.2% ropivacaine will be injected incrementally with repeated aspiration to avoid intravascular injection. No additional peripheral nerve blocks will be performed. All patients will receive standardized spinal anesthesia and multimodal postoperative analgesia.
The suprainguinal fascia iliaca compartment block will be performed under ultrasound guidance using a high-frequency linear probe placed in the sagittal oblique plane above the inguinal ligament. After identifying the fascia iliaca above the iliacus muscle, a 22-gauge echogenic needle will be advanced in-plane into the suprainguinal fascia iliaca space. A total of 30 mL of 0.2% ropivacaine will be injected to achieve cranial spread toward the femoral nerve, lateral femoral cutaneous nerve, and obturator nerve. All patients will receive standardized spinal anesthesia and multimodal postoperative analgesia.
The lumbar erector spinae plane block will be performed under ultrasound guidance at the L4 transverse process level. A curvilinear or linear ultrasound probe will be used to identify the erector spinae muscle and underlying transverse process. A 22-gauge echogenic needle will be inserted in-plane and advanced to the fascial plane deep to the erector spinae muscle and superficial to the transverse process. A total of 20 mL of 0.2% ropivacaine will be injected incrementally. No sacral ESPB will be added. All patients will receive standardized spinal anesthesia and multimodal postoperative analgesia.
Poznan University of Medical Sciences
Poznan, Poland
Total Opioid Consumption in the First 48 Hours After Surgery
Total cumulative opioid consumption recorded in the first 48 postoperative hours, converted to morphine milligram equivalents (MME). Includes all opioid medications administered as part of postoperative analgesia, both scheduled and rescue doses. Data will be extracted from electronic medication records and converted using standard MME conversion factors.
Time frame: 0-48 hours postoperatively
Time to First Rescue Opioid Administration
Time in hours from the end of surgery to the first administration of rescue opioid analgesia (5 mg intravenous oxycodone) triggered by a Numerical Rating Scale (NRS) pain score ≥ 4 or patient request.
Time frame: 0-48 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores at Rest
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Pain will be assessed by blinded study personnel at predefined intervals.
Time frame: 4 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores at Rest
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Pain will be assessed by blinded study personnel at predefined intervals.
Time frame: 8 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores at Rest
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Pain will be assessed by blinded study personnel at predefined intervals.
Time frame: 12 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores at Rest
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Pain will be assessed by blinded study personnel at predefined intervals.
Time frame: 24 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores at Rest
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Pain will be assessed by blinded study personnel at predefined intervals.
Time frame: 48 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores During Movement
Pain intensity during passive hip flexion or standardized physiotherapy-assisted mobilization using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Assessments performed by blinded study staff.
Time frame: 4 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores During Movement
Pain intensity during passive hip flexion or standardized physiotherapy-assisted mobilization using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Assessments performed by blinded study staff.
Time frame: 8 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores During Movement
Pain intensity during passive hip flexion or standardized physiotherapy-assisted mobilization using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Assessments performed by blinded study staff.
Time frame: 12 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores During Movement
Pain intensity during passive hip flexion or standardized physiotherapy-assisted mobilization using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Assessments performed by blinded study staff.
Time frame: 24 hours postoperatively
Numerical Rating Scale (NRS) Pain Scores During Movement
Pain intensity during passive hip flexion or standardized physiotherapy-assisted mobilization using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst pain). Assessments performed by blinded study staff.
Time frame: 48 hours postoperatively
Quadriceps Muscle Strength
Motor strength of knee extension and hip adduction assessed using the Medical Research Council (MRC) scale (0 = no contraction; 5 = normal strength) by two blinded assessors.
Time frame: 4 hours postoperatively
Quadriceps Muscle Strength
Motor strength of knee extension and hip adduction assessed using the Medical Research Council (MRC) scale (0 = no contraction; 5 = normal strength) by two blinded assessors.
Time frame: 8 hours postoperatively
Quadriceps Muscle Strength
Motor strength of knee extension and hip adduction assessed using the Medical Research Council (MRC) scale (0 = no contraction; 5 = normal strength) by two blinded assessors.
Time frame: 12 hours postoperatively
Quadriceps Muscle Strength
Motor strength of knee extension and hip adduction assessed using the Medical Research Council (MRC) scale (0 = no contraction; 5 = normal strength) by two blinded assessors.
Time frame: 24 hours postoperatively
Quadriceps Muscle Strength
Motor strength of knee extension and hip adduction assessed using the Medical Research Council (MRC) scale (0 = no contraction; 5 = normal strength) by two blinded assessors.
Time frame: 48 hours postoperatively
Incidence of Postoperative Nausea and Vomiting (PONV)
Presence of nausea, vomiting, or use of antiemetic medications documented by nursing staff and confirmed by blinded investigators.
Time frame: 0-24 hours postoperatively
Time to First Mobilization
Time in hours from the end of surgery until the patient is able to stand with physiotherapist assistance. Early mobilization follows institutional enhanced recovery protocols.
Time frame: 0-48 hours postoperatively
Adverse Events Related to Regional Anesthesia
Incidence of block-related complications including vascular puncture, local anesthetic systemic toxicity, persistent sensory deficit, motor deficit, or nerve injury as documented in hospital records.
Time frame: Up to 48 hours postoperatively
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