Comparison of Anterior Sciatic Nerve Block and Adductor Magnus Muscle Plane Block for Anterior Cruciate Ligament Surgery

Comparison of Anterior Sciatic Nerve Block and Adductor Magnus Muscle Plane Block Added to Adductor Canal Block in Patients Undergoing Anterior Cruciate Ligament Surgery

Anterior cruciate ligament (ACL) reconstruction is frequently associated with moderate-to-severe postoperative pain despite its arthroscopic nature, owing to the complex sensory innervation of the knee involving the femoral, sciatic, and obturator nerves. Multimodal analgesic strategies, particularly peripheral nerve blocks, are therefore widely used to improve postoperative pain control and reduce opioid consumption. Although anterior sciatic nerve block can be combined with adductor canal block in the supine position, its application may be technically challenging because of the deep localization of the sciatic nerve. Recently, adductor magnus muscle plane block has emerged as a potentially easier alternative by indirectly targeting the terminal branches of the sciatic nerve through fascial plane spread. In this study, we compared the efficacy of anterior sciatic nerve block and adductor magnus muscle plane block, both combined with adductor canal block.

Study Overview

• Status: Completed
• Conditions: ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION
• Intervention / Treatment: Procedure: Adductor canal block; Procedure: Anterior sciatic nerve block; Procedure: Adductor magnus plane block

Detailed Description

This single-center, prospective, randomized clinical trial included 90 patients aged 18-45 years with ASA physical status I-II who underwent arthroscopic anterior cruciate ligament reconstruction under spinal anesthesia. Patients were randomly allocated into three groups to receive either adductor canal block alone (Group C), adductor canal block combined with anterior sciatic nerve block (Group ASB), or adductor canal block combined with adductor magnus muscle plane block (Group AMB). Randomization was performed using a computer-generated sequence with concealed allocation through sealed opaque envelopes. Although the anesthesiologist performing the blocks was aware of group allocation, all postoperative assessments were conducted by an independent blinded investigator. All regional blocks were ultrasound-guided and performed preoperatively by the same experienced anesthesiologist using standardized techniques and local anesthetic volumes. Procedural characteristics, including block performance time, needle visibility, needle passes, and sonographic visibility of target structures, were systematically recorded. Sensory blockade was assessed at predefined intervals using cold-warm discrimination tests across multiple nerve distributions.

All patients received standardized spinal anesthesia with hyperbaric bupivacaine, as well as a multimodal postoperative analgesic regimen including intravenous paracetamol, dexketoprofen, and fentanyl-based patient-controlled analgesia. Postoperative pain scores at rest and during movement were evaluated at multiple time points during the first 24 hours, while cumulative fentanyl consumption, time to first PCA demand, and rescue analgesic requirements were recorded. Opioid-related adverse events, including nausea, vomiting, constipation, pruritus, dry mouth, and urinary retention, were also documented. In addition, postoperative motor function of the tibialis anterior and quadriceps femoris muscles was assessed using a three-point qualitative motor scale at predefined postoperative intervals up to 48 hours.

• Study Type: Interventional
• Enrollment (Actual): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Erzurum, Turkey (Türkiye), 25100
    • Ataturk Universtiy

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Anesthesiologists (ASA) physical status I-II,
• Scheduled for arthroscopic anterior cruciate ligament reconstruction

Exclusion Criteria:

• cardiovascular disease,
• hepatic dysfunction,
• coagulopathy or current use of anticoagulant therapy,
• inability to cooperate,
• known allergy to any of the study medications,
• refusal to participate in the study

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Adductor Canal Block; Participants in this arm will receive an ultrasound-guided adductor canal block using 20 mL of 0.25% bupivacaine. Blocks will be performed under sterile ultrasound guidance by an experienced anesthesiologist who will not participate in postoperative assessments. All patients will receive standardized spinal anesthesia and perioperative analgesia.	Procedure: Adductor canal block; Ultrasound transducer was placed perpendicular to the thigh to visualize the sartorius muscle, femoral artery and vein, and the adductor canal. Following infiltration of the skin and subcutaneous tissue with 2% lidocaine, a 22-gauge, 10-cm echogenic needle was advanced in-plane from lateral to medial toward the adductor canal. After confirming correct needle tip placement with 2 mL of 0.9% NaCl solution, 20 mL of 0.25% bupivacaine was administered.; Other Names: ACB
Active Comparator: Adductor Canal + Anterior Sciatic nerve block; Participants in this arm will receive an ultrasound-guided anterior sciatic nerve block (20 mL of 0.25% bupivacaine) and adductor canal block (20 mL of 0.25% bupivacaine). Blocks will be performed under sterile ultrasound guidance by an experienced anesthesiologist who will not participate in postoperative assessments. All patients will receive standardized spinal anesthesia and perioperative analgesia.	Procedure: Adductor canal block; Ultrasound transducer was placed perpendicular to the thigh to visualize the sartorius muscle, femoral artery and vein, and the adductor canal. Following infiltration of the skin and subcutaneous tissue with 2% lidocaine, a 22-gauge, 10-cm echogenic needle was advanced in-plane from lateral to medial toward the adductor canal. After confirming correct needle tip placement with 2 mL of 0.9% NaCl solution, 20 mL of 0.25% bupivacaine was administered.; Other Names: ACB; Procedure: Anterior sciatic nerve block; An ultrasound transducer was placed perpendicular to the anterior thigh. The sartorius muscle, femoral artery and vein, adductor longus muscle, adductor magnus muscle, and the sciatic nerve were identified. Following infiltration of the skin and subcutaneous tissue with 2% lidocaine, a 22-gauge, 10-cm echogenic needle was advanced toward the sciatic nerve under ultrasound guidance. Nerve stimulation was applied, and an appropriate motor response in the sciatic nerve distribution was obtained at 0.2-0.5 mA. After injection of 2 mL of 0.9% saline and visualization of perineural spread to confirm correct needle placement, 20 mL of 0.25% bupivacaine was administered.; Other Names: ASB
Active Comparator: Adductor Canal + Adductor magnus plane block; Participants in this arm will receive an ultrasound-guided adductor magnus plane block (20 mL of 0.25% bupivacaine) and an adductor canal block (20 mL of 0.25% bupivacaine). Blocks will be performed under sterile ultrasound guidance by an experienced anesthesiologist who will not participate in postoperative assessments. All patients will receive standardized spinal anesthesia and perioperative analgesia.	Procedure: Adductor canal block; Ultrasound transducer was placed perpendicular to the thigh to visualize the sartorius muscle, femoral artery and vein, and the adductor canal. Following infiltration of the skin and subcutaneous tissue with 2% lidocaine, a 22-gauge, 10-cm echogenic needle was advanced in-plane from lateral to medial toward the adductor canal. After confirming correct needle tip placement with 2 mL of 0.9% NaCl solution, 20 mL of 0.25% bupivacaine was administered.; Other Names: ACB; Procedure: Adductor magnus plane block; An ultrasound transducer was placed perpendicular to the thigh to visualise the sartorius muscle, femoral artery and vein, adductor longus, and the underlying adductor magnus muscle. Following infiltration of the skin and subcutaneous tissue with 2% lidocaine, a 22-gauge, 10-cm echogenic needle was advanced until the posterior fascia of the adductor magnus muscle was penetrated. After injection of 2 mL of 0.9% NaCl solution, correct needle placement was confirmed by observing fluid spread beneath the posterior surface of the adductor magnus muscle. Subsequently, 20 mL of 0.25% bupivacaine was administered.; Other Names: AMB

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opioid consumption	Postoperative opioid consumption	0-4 hours, 4-8 hours, 8-24 hours, Total 24-hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Scores (VAS) at Rest and During Movement	Pain intensity will be evaluated using the Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst pain). Assessments will be performed at rest and during movement at predefined postoperative time points.	PACU, 1st hour, 2nd hours, 4th hours, 8th hours, 12th hours, 24th hours
Adverse Effects	Opioid-Related Adverse Effects	up to 24 hours
Evaluation of Nerve Blockade after Nerve Block Application	Post-block sensory assessment was performed at predefined time intervals using a cold-warm discrimination test. Sensory evaluation was conducted at the plantar surface of the foot for the tibial nerve, the dorsal surface of the foot for the superficial peroneal nerve, the posterolateral aspect of the leg for the sural nerve, the posterior aspect of the thigh for the posterior femoral cutaneous nerve, and at the medial malleolus for the saphenous nerve.	5., 10., 15., 20., 30., and 45. minutes
Quadriceps and Anterior Tibialis Muscle Strength	Muscle strength will be assessed using standardized manual muscle testing (paralysis/paresis/normal) for quadriceps and anterior tibialis muscles.	4th hours, 8th hours, 12th hours, 24th hours, 48th hours

Collaborators and Investigators

• Sponsor: Ataturk University
• Investigators: Study Chair: Samet Kapakin, Professor, Ataturk University

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2024
• Primary Completion (Actual): March 1, 2026
• Study Completion (Actual): April 1, 2026

Study Registration Dates

• First Submitted: May 11, 2026
• First Submitted That Met QC Criteria: May 15, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 15, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Anterior Cruciate Ligament Surgery; Adductor Canal Block; Anterior Sciatic Nerve Block; Adductor Magnus Muscle Plane Block
• Other Study ID Numbers: B.30.2.ATA.0.01.00/761

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No