Ultrasound-guided Interscalene Block Versus Infraspinatus-Teres Minor Plane Block in Shoulder Arthroscopy ((ISB)-(ITM))

Ultrasound-guided Interscalene Block (ISB) Versus Infraspinatus-Teres Minor (ITM) Interfacial Plane Block in Shoulder Arthroscopic Surgery

This study aims to compare the efficacy and safety of ultrasound-guided Interscalene block (ISB) versus Infraspinatus-Teres minor (ITM) interfacial plane block in shoulder arthroscopic surgery.

A prospective, randomized clinical trial will be conducted with 46 patients. Approval was obtained from the Medical Ethics Committee (2022/0126), and written informed consent will be collected from all participants. Patients aged 20-70, ASA I-II, scheduled for arthroscopic shoulder surgery will be divided before the induction of general anesthesia (GA) into two groups:

Group A: will receive the ultrasound guided ISB technique with a 15ml solution of 7.5ml lidocaine 2% and 7.5ml bupivacaine 0.5% be injected between the anterior and middle scalene muscles.

Group B: will receive the ultrasound guided ITM block with the same anesthetic solution be injected between the infraspinatus and teres minor muscles.

Researchers will examine the following outcomes;

1. Primary outcome measure: Efficacy of analgesia by Pain score; will be measured by Numerical Rating Scale (NRS) score (0=no pain,1-3=mild,4-6=moderate,7-9=sever,10=most sever) at postoperative 12 hour.

2. Secondary outcome measures:

   1. Duration of analgesia, starting from recovery from general anesthesia (GA) to 1st time giving the patient rescue analgesia ( measured by NRS pain score at 0, 6 ,12, 18 and 24 postoperative hours)
   2. Risk of complications from techniques
   3. Patient satisfaction after surgery.
   4. Rescue analgesic consumption
   5. Hemodynamics monitoring; measurements of heart rate and mean arterial blood pressure before induction of anesthesia and every 15 minutes during surgery till end of surgery

Study Overview

• Status: Active, not recruiting
• Conditions: Pain; Pain Management; Pain Management in Postoperative Care
• Intervention / Treatment: Procedure: Group A: will receive an ultrasound-guided interscalene block (ISB); Procedure: Group B:will receive an ultrasound-guided infraspinatus-teres minor (ITM) interfacial plane block

Detailed Description

I. Study design:

Randomized comparative study.

II. Study setting and location:

The study will be conducted at the operative room of Souad Kafafi University Hospital (SKUH), Misr University of science and Technology (MUST).

III. Study population:

Patients aged from 20 to 60 years old scheduled for shoulder surgery will be randomized in a 1:1 ratio after induction of general anesthesia (GA) to either: Group A: Received the ultrasound guided ISB technique with a 15ml solution of 7.5ml lidocaine 2% and 7.5ml bupivacaine 0.5% injected between the anterior and middle scalene muscles.

Group B: Received the ultrasound guided ITM block with the same anesthetic solution injected between the infraspinatus and teres minor muscles.

IV. Study procedures:

1. Randomization Patients will be randomly allocated by a computer-generated table into one of the study groups; the randomization sequence will be concealed in sealed opaque envelopes.

2. Study protocol

   • All Patients will have a pre-operative assessment visit, which will include; history taking, complete physical examination and review of all the results of the routine investigations (CBC, Coagulation profile, renal functions, liver functions).
   • On Arrival to the preparation room, they will receive the following premedication via intravenous (IV) route: Midazolam 0.03 mg/kg, Ondansetron 4 mg and Omeprazole 40 mg iv infusion.
   • Upon Arrival to the operating room, standard monitoring will be applied which include: Pulse Oximeter, Noninvasive Blood Pressure and Six-lead electrocardiogram (ECG).
   • General anesthesia will be induced using: Propofol 1-2mg/kg, Fentanyl1-2 μg/kg, Morphine 0.1mg/kg and Atracurium 0.5 mg/kg.
   • After endotracheal intubation, side way capnography will be applied to measure end tidal CO2 pressure in the expired air.
   • General anesthesia will be maintained using Sevoflurane 1-2 MAC (Mean Alveolar Concentrations) in O2/ Air 50% / 50%, Paracetamol 1gm iv infusion, ketorolac 30 mg iv and incremental doses of Atracurium 0.1mg/kg/30 minutes.

The patients will be randomly allocated into two groups:

Group A:

Ultrasound-guided Interscalene block (ISB) technique.

Group B:

Ultrasound-guided Infraspinatus-teres minor (ITM) interfacial plane block technique

V. Study outcomes:

1. Primary outcome measure:

   • Efficacy of analgesia by Pain score; will be measured by Numerical Rating Scale (NRS) score (0-10; 0=no pain,1-3=mild,4-6=moderate,7-9=sever,10=most sever) at postoperative12 hours.

2. Secondary outcome measures:

   1. Duration of analgesia, starting from recovery from general anesthesia (GA) to 1st time giving the patient rescue analgesia ( measured by NRS pain score at 0, 6 ,12, 18 and 24 postoperative hours).
   2. Risk of complications from techniques.
   3. Patient satisfaction after surgery
   4. Total intraoperative analgesia dose (fentanyl consumption) and total postoperative analgesia dose (morphine consumption).
   5. Hemodynamics monitoring; measurements of heart rate and mean arterial blood pressure before induction of anesthesia and every 15 minutes during surgery till end of surgery

VII. Statistical analysis:

1. Sample size:

   Sample size calculation was based on pain score after Interscalene block (ISB) in shoulder surgery versus other methods retrieved from previous research (Singelyn et al., 2004) (15). Using G power program version 3.1.9.4 to calculate sample size based on effect size of 0.897 (35 ± 25) versus (13±24), using 2-tailed test, α error =0.05 and power = 80.0%, the total calculated sample size will be 21 in each group at least and by adding 10% to compensate for possible drop out then total sample size per group is 23 cases at least.

2. Statistical analysis:

Data will be analyzed using SPSS (statistical package for social sciences) version 22. Quantitative data will be tested for normality by Kolmogrov-Smironv test then described as mean and standard deviation for normally distributed data, and median and range for non-normally distributed, Qualitative data will be presented as number and percent. The appropriate statistical test will be applied according to data type with the following suggested tests: Student t test and Mann Whitney U test for continuous variables, Chi-Square test for categorical variable.

• Study Type: Interventional
• Enrollment (Estimated): 46
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Giza, Egypt, 15525
    • Souad Kafafi University Hospital (SKUH), faculty of medicine, Misr University for Science and Technology (MUST)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Patients aged 20 to 60,
• ASA classification I or II,
• scheduled for arthroscopic shoulder surgery,
• will be randomized 1:1 into two groups before the induction of general anesthesia (GA)

Exclusion Criteria:

• Patients who refuse participation.
• Have allergies to local anesthetics.
• Phrenic nerve dysfunction.
• Chronic opioid use.
• ASA III or higher classification.
• Coagulopathy.
• Severe chronic obstructive pulmonary disease.
• Local infection at the injection site

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Group A : Ultrasound guided Interscalene block (ISB) technique; Interscalene block (ISB) technique, patients will be place in the supine position and the patient's head facing away from the side to be blocked. The Ultrasound probe will be applied in sterile fashion on the supraclavicular fossa to find the brachial plexus division lateral to the subclavian artery. Then, the probe will be traced cephalad to the C5-C6 root and interscalene muscles at the level of the cricoid cartilage	Procedure: Group A: will receive an ultrasound-guided interscalene block (ISB); Group A: will receive an ultrasound-guided interscalene block (ISB) using a 15ml mixture of lidocaine (7.5ml 2%) and bupivacaine (7.5ml 0.5%).
Experimental: Group B: Ultrasound guided Infraspinatus-teres minor (ITM) interfacial plane block technique; Infraspinatus-teres minor (ITM) interfacial plane block technique, Patients will be placed in the lateral position, and a pillow will be wedged under the anterior shoulder and upper arm. The Ultrasound probe will be applied in sterile fashion and put angled obliquely, to be perpendicular to the direction of muscles to obtain the transverse scan of muscles for the ITM block. After palpation of the posterolateral corner of the acromion, the muscle-tendon units of infraspinatus (IS) and teres minor (Tm) on the humeral head will be identified below the corner. At this time, the probe will be moved slightly caudad to identify the borders of Tm. Once the IS and Tm on the humeral head area identified, by moving the probe medio caudally, the interfascial structure of the IS and Tm could be traced on the posterior surface area of the neck of the scapula.	Procedure: Group B:will receive an ultrasound-guided infraspinatus-teres minor (ITM) interfacial plane block; Group B:will receive an ultrasound-guided infraspinatus-teres minor (ITM) interfacial plane block using a 15ml mixture of lidocaine (7.5ml 2%) and bupivacaine (7.5ml 0.5%).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Efficacy of analgesia	Will be measured by pain score at 12 hours postoperatively using the Numerical Rating Scale (NRS) (0-10; with 0 means no pain and 10 means most intolerable pain)	at 12 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of analgesia	duration of analgesia measured by Pain score at 0, 6, 12, 18, and 24 hours postoperatively using the Numerical Rating Scale (NRS) 0-10 with 0 means no pain and 10 means most intolerable pain.	Starting from recovery from general anesthesia (GA) to 1st time giving the patient rescue analgesia,
Hemodynamics (heart rate)	measurements of heart rate (beat per minute)	before induction of anesthesia and every 15 minutes during surgery till end of surgery
Total intraoperative analgesic consumption (fentanyl).	Need and consumption of fentanyl intraoperatively (ug),	During surgery; from induction of anesthesia to end of surgery.
Patient satisfaction	very unsatisfied, unsatisfied, neutral, satisfied, very satisfied	for the first postoperative 24 hours
Complications of the techniques	Local anesthetics toxicity, pneumothorax, phrenic nerve palsy, hematoma formation	From time of injection to the end of first 24 hours postoperative
Total postoperative morphine consumption (mg)	Time to 1st request of rescue analgesia and total dose of postoperative morphine consumption in the studied groups for 24 hours (mg)	From recovery from general anesthesia to end of 24hours postoperatively
Hemodynamics; mean arterial blood pressure (mmHg)	Measurement of mean arterial blood pressure (mmHg)	Before induction of anesthesia and every 15 minutes during surgery till end of surgery

Collaborators and Investigators

• Sponsor: Misr University for Science and Technology
• Investigators: Study Chair: Mohammed Hany Kamal, Prof. of anesthesia and pain, Misr University for Science and Technolog

Publications and helpful links

General Publications

• Hewson DW, Oldman M, Bedforth NM. Regional anaesthesia for shoulder surgery. BJA Educ. 2019 Apr;19(4):98-104. doi: 10.1016/j.bjae.2018.12.004. Epub 2019 Feb 6. No abstract available.

Study record dates

Study Major Dates

• Study Start (Actual): June 15, 2025
• Primary Completion (Estimated): January 20, 2026
• Study Completion (Estimated): January 31, 2026

Study Registration Dates

• First Submitted: May 24, 2025
• First Submitted That Met QC Criteria: June 3, 2025
• First Posted (Actual): June 11, 2025

Study Record Updates

• Last Update Posted (Actual): July 23, 2025
• Last Update Submitted That Met QC Criteria: July 19, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Ultrasound guided,; interscaline block,; versus infraspinatus-teres minor block; shoulder arthroscopy.
• Other Study ID Numbers: 2022/0126

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

Demographic Information: Age, sex, race, and other relevant demographic details.

Baseline Characteristics: Health status, medical history, and any pre-existing conditions prior to the trial.

Treatment Assignment: Information on the intervention or treatment each participant received.

Outcome Measures: Data on primary and secondary outcomes as defined in the trial protocol.

Adverse Events: Reports of any side effects or adverse events experienced by participants during the trial.

Follow-up Data: Information collected during follow-up periods, including long-term outcomes.

• IPD Sharing Time Frame: 01/06//2025 to 31/5/2026

IPD Sharing Access Criteria

Researchers:

Who: Academic researchers, industry scientists, and regulatory agencies. What: Full IPD, including demographic data, treatment assignments, and outcome measures.

How: Through data sharing platforms or repositories after submitting a research proposal and obtaining necessary approvals.

Regulatory Authorities:

Who: Agencies like the FDA or EMA. What: Full IPD and supporting documentation for oversight and review. How: Direct access during the review process of clinical trial applications.

Data Sharing Initiatives:

Who: Collaborating institutions and consortia. What: Aggregated or anonymized IPD for meta-analyses or systematic reviews. How: Via established partnerships and shared databases.

Public and Patient Advocacy Groups:

Who: Organizations seeking to promote transparency. What: Summary data and aggregated results, but not individual-level data. How: Through publicly available reports or dashboards.

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

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