Investigation of the Relationship Between Shoulder Alpha Angle and Humeral Head Displacement Percentage Measured by Ultrasonography in Neonatal Brachial Plexus Palsy Infants With Clinical Parameters

This study will examine infants with a birth-related nerve injury called neonatal brachial plexus palsy, which can affect movement in the arm and sometimes cause the shoulder joint to shift out of its normal position (subluxation). Researchers will use ultrasound imaging to measure the shoulder joint and will compare these measurements with findings from a physical examination, to determine which clinical signs can help predict whether a baby's shoulder will develop this problem. The goal is to help doctors detect shoulder problems earlier, so that treatment can start sooner.

Study Overview

• Status: Not yet recruiting
• Conditions: Glenohumeral Subluxation; Neonatal Brachial Plexus Palsy; Brachial Plexus Injuries
• Intervention / Treatment: Diagnostic test: Shoulder Ultrasonography; Other: Standardized Clinical Examination

Detailed Description

Infants aged 3 months to 1 year with neonatal brachial plexus injury (Narakas Group I-III) will be evaluated at a single pediatric rehabilitation clinic. At each visit, the same physiatrist will perform a standardized clinical examination, including assessment of demographic and obstetric history, subluxation-specific clinical signs (axillary skin fold asymmetry, palpable posterior fullness), passive range of motion, upper extremity length discrepancy, the Active Movement Scale, and the Toronto Test Score. A second physiatrist, blinded to clinical findings, will perform shoulder ultrasonographic evaluation using a posterior approach to measure the alpha angle and the percentage of humeral head displacement (PHHD). Glenohumeral subluxation will be defined as an alpha angle greater than 30 degrees; dislocation will be defined as an alpha angle greater than 30 degrees combined with PHHD greater than 50%. Associations between clinical findings and ultrasonographic subluxation will be analyzed using Generalized Linear Mixed Models to account for repeated measurements per patient, followed by ROC curve analysis to identify optimal predictive thresholds.

• Study Type: Observational
• Enrollment (Estimated): 19

Contacts and Locations

• Study Contact: Name: Melike Nur Rençber, MD; Phone Number: +90 553 770 28 43; Email: melibalat@gmail.com
• Study Contact Backup: Name: Esra Giray, MD; Phone Number: +90 555 813 43 94; Email: girayesra@hotmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye), 34668
    • University of Health Sciences Turkey, Fatih Sultan Mehmet Training and Research Hospital
    • Principal Investigator: Esra Giray, MD
    • Contact: Melike Nur Rençber, MD; Phone Number: +90 553 770 28 43; Email: melibalat@gmail.com
    • Contact: Esra Giray, MD; Phone Number: +90 555 813 43 94; Email: girayesra@hotmail.com
    • Sub-Investigator: Melike Nur Rençber, MD

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Infants diagnosed with neonatal brachial plexus injury who present to the Pediatric Rehabilitation Clinic of the University of Health Sciences Turkey, Fatih Sultan Mehmet Training and Research Hospital, and who meet the eligibility criteria, will be consecutively enrolled in the study

Description

Inclusion Criteria:

• Diagnosis of neonatal brachial plexus injury (NBPI) between 3 months and 1 year of age
• Narakas classification Group I, II, or III
• Absence of nerve root avulsion

Exclusion Criteria:

• Prior shoulder surgery for NBPI
• Inability to tolerate ultrasonographic examination
• Concomitant musculoskeletal (e.g., torticollis, humeral fracture) or neurological disease
• Bilateral NBPI
• Narakas classification Group IV
• Botulinum toxin injection to the affected shoulder

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Infants with Neonatal Brachial Plexus Palsy; Infants aged 3 months to 1 year with neonatal brachial plexus injury (Narakas Group I-III) who will undergo standardized clinical examination and shoulder ultrasonographic evaluation at each visit.

Diagnostic test: Shoulder Ultrasonography; Ultrasonographic measurement of the shoulder alpha angle and percentage of humeral head displacement (PHHD), to be performed at each clinical visit.; Other: Standardized Clinical Examination; Standardized physical examination including passive range of motion, Active Movement Scale, Toronto Test Score, and subluxation-specific clinical signs, to be performed at each visit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ultrasonographic Alpha Angle	Alpha angle will be measured sonographically at each shoulder examination. Glenohumeral subluxation will be defined as an alpha angle greater than 30 degrees.	Assessed at each clinical visit from 3 months to 1 year of age
Percentage of Humeral Head Displacement (PHHD)	PHHD will be measured sonographically at each shoulder examination. Glenohumeral dislocation will be defined as an alpha angle greater than 30 degrees combined with PHHD greater than 50%.	Assessed at each clinical visit from 3 months to 1 year of age

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Passive Range of Motion of the Shoulder and Elbow	Passive range of motion of the shoulder (flexion, extension, abduction, internal and external rotation) and elbow (flexion, extension) will be measured using standard goniometry at each visit and evaluated for association with glenohumeral subluxation.	Assessed at each clinical visit from 3 months to 1 year of age
Active Movement Scale (AMS) Score	AMS score will be assessed at each visit as a clinical predictor of glenohumeral subluxation.	Assessed at each clinical visit from 3 months to 1 year of age
Toronto Test Score	Toronto Test Score will be calculated at each visit and evaluated for association with glenohumeral subluxation.	Assessed at each clinical visit from 3 months to 1 year of age
Subluxation-Specific Clinical Signs (Axillary Skin Fold Asymmetry and Palpable Posterior Fullness)	Presence of axillary skin fold asymmetry and palpable posterior shoulder fullness will be assessed at each visit and evaluated for association with glenohumeral subluxation.	Assessed at each clinical visit from 3 months to 1 year of age
Upper Extremity Length Discrepancy	Difference in upper extremity length between the affected and unaffected sides will be measured at each visit and evaluated for association with glenohumeral subluxation.	Assessed at each clinical visit from 3 months to 1 year of age
Reinnervation Status	Neurological reinnervation status (full, partial, or none) will be assessed at each visit relative to the prior visit.	Assessed at each clinical visit from 3 months to 1 year of age

Collaborators and Investigators

• Sponsor: Fatih Sultan Mehmet Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): November 1, 2027

Study Registration Dates

• First Submitted: August 12, 2026
• First Submitted That Met QC Criteria: August 12, 2026
• First Posted (Actual): August 17, 2026

Study Record Updates

• Last Update Posted (Actual): August 17, 2026
• Last Update Submitted That Met QC Criteria: August 12, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Erb's Palsy; Alpha Angle; Shoulder Ultrasonography; Glenohumeral Dysplasia; Humeral Head Displacement
• Additional Relevant MeSH Terms: Shoulder Injuries; Musculoskeletal Diseases; Nervous System Diseases; Wounds and Injuries; Neuromuscular Diseases; Joint Diseases; Peripheral Nervous System Diseases; Infant, Newborn, Diseases; Joint Dislocations; Birth Injuries; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Neonatal Brachial Plexus Palsy; Shoulder Dislocation; Brachial Plexus Neuropathies
• Other Study ID Numbers: 24/648

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

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