Comparison of Postoperative Analgesic Efficacy of Interscalene and Suprascapular Blocks Used in Arthroscopic Shoulder Surgery

March 17, 2026 updated by: Durali Bayka, Aydin Adnan Menderes University

Comparison of the Analgesic Effects and Side Effects of Interscalene and Suprascapular Blocks for Pain Control Following Arthroscopic Shoulder Surgery

The Importance of Postoperative Analgesia in Shoulder Surgery

Shoulder surgery is an orthopedic procedure that can be performed either through open surgery or arthroscopically. Pain following shoulder surgery can lead to adverse outcomes such as decreased functional status, increased consumption of narcotic analgesics, and the development of chronic pain.

Therefore, achieving optimal postoperative shoulder analgesia is important not only for patient comfort and satisfaction but also for promoting functional recovery, preventing chronic pain, and reducing the need for narcotic analgesics. Additionally, minimizing the side effects associated with nerve block techniques used for analgesia is crucial for the overall success of the treatment.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

The innervation of the shoulder joint is provided by the axillary, musculocutaneous, subscapular, and suprascapular nerves, all of which originate from the brachial plexus. The suprascapular nerve passes through the suprascapular notch on the superior border of the scapula and supplies motor branches to the rotator cuff muscles. Suprascapular nerve block is widely used in the management of shoulder pain.

Regional anesthesia techniques are among the most effective methods for postoperative analgesia. Peripheral nerve blocks, a subtype of regional anesthesia, are particularly suitable for postoperative pain control in shoulder surgeries due to their ability to provide long-lasting and effective analgesia, reduce opioid requirements and related side effects or dependency, and facilitate recovery by promoting early functional restoration.Interscalene brachial plexus block (ISB) is commonly used for analgesia in shoulder surgery and is considered the gold standard technique. However, ISB also blocks the phrenic nerve (C3-C5), which may result in ipsilateral hemidiaphragmatic paresis (HDP). This can cause respiratory complications, particularly in patients with preexisting pulmonary disease, obstructive sleep apnea, or morbid obesity.

The suprascapular nerve block (SSB), applied at a more distal level of the brachial plexus, preserves the phrenic nerve and thus minimizes the respiratory side effects associated with ISB.

Study Type

Observational

Enrollment (Estimated)

84

Contacts and Locations

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

Study Locations

  • Turkey (Türkiye)
    • Efeler
      • Aydin, Efeler, Turkey (Türkiye), 09010
        • Adnan menderesüniversite Hastanesi

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

Yes

Sampling Method

Probability Sample

Study Population

Once suitability is confirmed, detailed information about the work programs is provided in glossary and written form. Random grouping (randomization) and work will be specifically approved after being informed before any process.

Description

Inclusion Criteria:

  1. Patients who have provided written informed consent
  2. Patients over 18 years of age scheduled for elective shoulder arthroscopy
  3. Patients classified as ASA I-II
  4. Patients undergoing general anesthesia

Exclusion Criteria:

  1. Patients undergoing shoulder surgery other than arthroscopic procedures (e.g., revision or open surgery)
  2. Patients with pre-existing respiratory, cardiac, renal, neurological, or hepatic diseases
  3. Presence of neuropathy affecting the brachial plexus
  4. Contraindications to peripheral nerve block (e.g., coagulopathy)
  5. Known allergy to local anesthetics

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Suprascapular block
For Group I, after the patients were positioned in the sitting posture, reference points were identified based on anatomical landmarks, including the scapular spine and the acromion. A linear ultrasound probe (13-6 MHz) was used to guide the procedure, targeting the suprascapular notch. Under sterile conditions, a 22-gauge × 100 mm needle (Braun® Stimuplex) was advanced, and following negative aspiration, 15 mL of 0.5% bupivacaine was injected.
Other: rescue analgesia
In the postoperative recovery room, patients with a Numeric Rating Scale (NRS) score of 4 or higher received 100 mg of intravenous tramadol as rescue analgesia. In addition, both groups routinely received 1 g of intravenous paracetamol every 6 hours during their stay in the ward. During ward follow-up, if the NRS score was 4 or higher, 100 mg of intravenous tramadol was administered as needed.
Interscalene block
For Group II, patients were positioned in the supine or semi-sitting position with the head turned to the contralateral side to facilitate access to the lateral aspect of the neck. Following antiseptic skin preparation, a high-frequency linear ultrasound probe (6-13 MHz) was placed transversely on the lateral neck. The C5-C7 nerve roots were identified as hyperechoic structures located between the anterior and middle scalene muscles. Using an in-plane ultrasound-guided approach, a 22-gauge, 50-100 mm nerve block needle was advanced into the interscalene groove. After confirming negative aspiration, 15 mL of 0.5% bupivacaine was administered around the nerve roots.
Other: rescue analgesia
In the postoperative recovery room, patients with a Numeric Rating Scale (NRS) score of 4 or higher received 100 mg of intravenous tramadol as rescue analgesia. In addition, both groups routinely received 1 g of intravenous paracetamol every 6 hours during their stay in the ward. During ward follow-up, if the NRS score was 4 or higher, 100 mg of intravenous tramadol was administered as needed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The analgesic efficacy of interscalene block (ISB) and suprascapular block (SSB) will be compared in patients undergoing shoulder arthroscopy.
Time Frame: the first 48 hours postoperatively
It is a pain intensity assessment system based on the patient indicating a point between 0 (no pain) and 10 (unbearable pain) to describe their pain level.
the first 48 hours postoperatively

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The development of chronic pain following interscalene block (ISB) and suprascapular block (SSB) will be compared in patients undergoing shoulder arthroscopy.
Time Frame: 3 months postoperatively
Postoperative chronic pain will be evaluated after 3 months using a numerical rating pain scale: 0 (no pain) to 10 (unbearable pain).
3 months postoperatively

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
The side effects of interscalene block (ISB) and suprascapular block (SSB) will be compared in patients undergoing shoulder arthroscopy.
Time Frame: the first 48 hours postoperatively
The number of patients with dyspnea symptoms after suprascapular and interscalene blocks applied after arthroscopic shoulder surgery will be compared.
the first 48 hours postoperatively

Collaborators and Investigators

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

Sponsor

Aydin Adnan Menderes University

Investigators

  • Principal Investigator: Durali BAYKA

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)

January 1, 2024

Primary Completion (Estimated)

January 1, 2027

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

July 24, 2025

First Submitted That Met QC Criteria

March 17, 2026

First Posted (Actual)

March 19, 2026

Study Record Updates

Last Update Posted (Actual)

March 19, 2026

Last Update Submitted That Met QC Criteria

March 17, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2023/12/01

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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