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Completed

NCT Number: NCT07601529

Comparison of Anterior Sciatic Nerve Block and Adductor Magnus Muscle Plane Block for 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.

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Key information

Conditions

Anterior Cruciate Ligament Reconstruction

Age range

18 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Ataturk Universtiy

Erzurum, 25100, Turkey (Türkiye)

About this study

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.

Who can participate

Healthy volunteers accepted: No

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

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

Treatment and study plan

Adductor canal block

Procedure

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

Anterior sciatic nerve block

Procedure

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

Adductor magnus plane block

Procedure

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

Primary outcomes

  1. Opioid consumption

    Time frame: 0-4 hours, 4-8 hours, 8-24 hours, Total 24-hour

    Postoperative opioid consumption

Secondary outcomes

  1. Pain Scores (VAS) at Rest and During Movement

    Time frame: PACU, 1st hour, 2nd hours, 4th hours, 8th hours, 12th hours, 24th hours

    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.

  2. Adverse Effects

    Time frame: up to 24 hours

    Opioid-Related Adverse Effects

  3. Evaluation of Nerve Blockade after Nerve Block Application

    Time frame: 5., 10., 15., 20., 30., and 45. minutes

    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.

  4. Quadriceps and Anterior Tibialis Muscle Strength

    Time frame: 4th hours, 8th hours, 12th hours, 24th hours, 48th hours

    Muscle strength will be assessed using standardized manual muscle testing (paralysis/paresis/normal) for quadriceps and anterior tibialis muscles.

Sponsors and collaborators

Lead sponsor

Ataturk University

Other

Registry information

Official study title

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

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
May 22, 2026
Registry last updated
May 22, 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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