Anterior Suprascapular and Axillary vs. Interscalene Block for Analgesia and Diaphragmatic Function in Shoulder Surgery

August 6, 2026 updated by: İbrahim Topcu, Ankara Etlik City Hospital

Comparison of Anterior Suprascapular and Axillary Nerve Block Versus Interscalene Block for Postoperative Analgesia and Diaphragmatic Function in Shoulder Surgery: A Randomized Controlled Trial

Shoulder surgeries are among the most frequently performed orthopedic interventions and are often associated with moderate to severe postoperative pain. In these procedures, effective pain management is crucial for early rehabilitation and patient comfort.

Peripheral nerve blockade is widely used for postoperative analgesia in shoulder surgery. While the interscalene brachial plexus block is considered the gold standard for pain control, it is frequently associated with unintended phrenic nerve blockade, leading to hemidiaphragmatic paresis. To minimize respiratory complications while maintaining effective analgesia, alternative diaphragm-sparing regional anesthesia techniques, such as the combination of suprascapular and axillary nerve blocks, have been introduced.

The aim of this study is to compare the analgesic efficacy and respiratory functions preservation of the ultrasound-guided anterior approach suprascapular combined with axillary nerve block versus interscalene block in patients undergoing shoulder surgery

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

70

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients aged between 18 and 65 years
  • American Society of Anesthesiologists (ASA) physical status I, II, or III
  • Patients scheduled to undergo elective arthroscopic shoulder surgery
  • BMI between 18 and 30 kg/m2
  • Ability to provide written informed consent

Exclusion Criteria:

  • Known allergy or hypersensitivity to local anesthetics
  • Presence of localized infection at the planned injection site
  • Severe coagulopathy or active use of anticoagulant medications
  • Contralateral phrenic nerve palsy or a diagnosis of severe chronic obstructive pulmonary disease (COPD)
  • History of chronic opioid consumption or neuropathic pain

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Interscalene Block
After the patients are placed under monitoring and positioned supine, and appropriate field sterilization is achieved, the ultrasound probe will be positioned transversely at the level of the cricoid cartilage (C6) with the head turned to the contralateral side. Advancing the needle laterally into the interscalene groove between the anterior and middle scalene muscles, 10 mL of local anesthetic (%0.5 bupivacaine ) will be injected between the C5 and C6 nerve roots.
Procedure: Interscalene Block
Interscalene block will be performed on the patients using 10 mL of 0.5% bupivacaine under ultrasound guidance.
Active Comparator: Combination of Axillary and Anterior Suprascapular Blocks
After the patients are placed under monitoring and positioned supine, and appropriate field sterilization is achieved, the ultrasound probe will be positioned transversely in the supraclavicular fossa with the head turned to the contralateral side. Advancing the needle in-plane, 5 mL of local anesthetic (%0.5 bupivacaine) will be injected around the suprascapular nerve as it branches anteriorly from the superior trunk of the brachial plexus. Subsequently, for the axillary nerve block, the patient will be positioned laterally and the ultrasound probe will be placed longitudinally over the posterior aspect of the shoulder. Advancing the needle into the quadrangular space, 5 mL of local anesthetic (%0.5 bupivacaine) will be injected around the axillary nerve adjacent to the posterior circumflex humeral artery.
Procedure: Combination of Axillary and Anterior Suprascapular Blocks
Combined anterior suprascapular(5 ml) and axillary nerve blocks(5 ml) will be performed on the patients using a total of 10 mL of 0.5% bupivacaine under ultrasound guidance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Pain Intensity at Rest
Time Frame: 4 hours after surgery.
Pain will be assessed using a visual analog scale from 0 mm (no pain) to 100 mm (worst pain) at rest. Pain assessment at rest will be made at 4 hours after surgery.
4 hours after surgery.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Pain Intensity at Rest
Time Frame: Up to 24 hours
Pain will be assessed using a visual analog scale from 0 mm (no pain) to 100 mm (worst pain) at rest. Pain assessment at rest will be made at 1, 8, 12, and 24 hours after surgery.
Up to 24 hours
Postoperative Pain Intensity at Movement
Time Frame: Up to 24 hours
Pain will be assessed using a visual analog scale from 0 mm (no pain) to 100 mm (worst pain) at movement. Pain assessment at rest will be made at 1, 4, 8, 12, and 24 hours after surgery.
Up to 24 hours
Total Postoperative Opioid Consumption
Time Frame: Up to 24 hours
The total amount of opioid consumed by the patient will be recorded.
Up to 24 hours
Area Under Curve
Time Frame: At the 24th hour
Cumulative 24-hour pain burden calculated by the trapezoidal rule
At the 24th hour
Diaphragmatic Excursion
Time Frame: Baseline (immediately before block performance) and 30 minutes after block performance
Diaphragmatic excursion will be measured in centimeters (cm) using M-mode ultrasonography during normal breathing and deep breathing (sniff test).
Baseline (immediately before block performance) and 30 minutes after block performance
Forced vital capacity (FVC) (volume)
Time Frame: Perioperative period
Forced vital capacity (FVC) (volume) will be evaluated during the perioperative period. Measurements will be performed before block administration (baseline), at 30 minutes after the block, and at postoperative 1 and 24 hours.
Perioperative period
Forced expiratory flow in 1 s (FEV1) (volume)
Time Frame: Perioperative period
Forced expiratory flow in 1 s (FEV1) (volume) will be evaluated during the perioperative period. Measurements will be performed before block administration (baseline), at 30 minutes after the block, and at postoperative 1 and 24 hours.
Perioperative period
FEV1/FVC
Time Frame: Perioperative period
FEV1/FVC will be evaluated during the perioperative period. Measurements will be performed before block administration (baseline), at 30 minutes after the block, and at postoperative 1 and 24 hours.
Perioperative period

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ankara Etlik City Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 6, 2026

Primary Completion (Estimated)

December 14, 2026

Study Completion (Estimated)

December 28, 2026

Study Registration Dates

First Submitted

July 28, 2026

First Submitted That Met QC Criteria

July 28, 2026

First Posted (Actual)

July 31, 2026

Study Record Updates

Last Update Posted (Actual)

August 7, 2026

Last Update Submitted That Met QC Criteria

August 6, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AEŞH-EK-2026-142

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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