NCT03921944 · Milton S. Hershey Medical Center
Evaluation of Structural and Functional Integrity of the Rotator Cuff After Total Shoulder Arthroplasty
What this study is about
The purpose of this study is to examine the rotator cuff muscles in your shoulder at one and two year post total shoulder replacement surgery.
View original scientific description
The purpose of this study is to examine the rotator cuff muscles in your shoulder at one and two year post total shoulder replacement surgery.
Interventions
DIAGNOSTIC_TEST
CT scan of the shoulders
studies of both operative and nonoperative shoulders
Primary outcome measures
Active Nerve Denervation
Time frame: one year post surgery
EMG examination will be performed by a single neurologist. The EMG Examination will be performed on the muscles (upper subscapularis, supraspinatus, infraspinatus, teres minor and rhomboid) to look for any presence or absence of active denervation. Presence indicated by increased insertional activity, fibrillation potential, positive sharp waves and/or with fasciculations in both operated and unoperated shoulders.
Active Nerve Denervation
Time frame: two year post surgery
EMG examination will be performed by a single neurologist. The EMG Examination will be performed on the muscles (upper subscapularis, supraspinatus, infraspinatus, teres minor and rhomboid) to look for any presence or absence of active denervation. Presence indicated by increased insertional activity, fibrillation potential, positive sharp waves and/or with fasciculations in both operated and unoperated shoulders.
Neuropathic Changes_amplitude
Time frame: one year post surgery
The EMG Examination will be performed on the muscles (upper subscapularis, supraspinatus, infraspinatus, teres minor and rhomboid) to look for the presence or absence of neuropathic changes assessed by examining unit morphology amplitude: measured in millivolts, in both operated and unoperated shoulders.
Neuropathic Changes_amplitude
Time frame: two year post surgery
The EMG Examination will be performed on the muscles (upper subscapularis, supraspinatus, infraspinatus, teres minor and rhomboid) to look for the presence or absence of neuropathic changes assessed by examining unit morphology amplitude: measured in millivolts, in both operated and unoperated shoulders.
Neuropathic Changes_recruitment pattern
Time frame: one year post surgery
The EMG Examination will be performed on the muscles (upper subscapularis, supraspinatus, infraspinatus, teres minor and rhomboid) to look for the presence or absence of neuropathic changes assessed by examining unit morphology: phases with recruitment pattern measured as 1-2 or 3-4 units in both operated and unoperated shoulders.
Neuropathic Changes_recruitment pattern
Time frame: two year post surgery
The EMG Examination will be performed on the muscles (upper subscapularis, supraspinatus, infraspinatus, teres minor and rhomboid) to look for the presence or absence of neuropathic changes assessed by examining unit morphology: phases with recruitment pattern measured as 1-2 or 3-4 units in both operated and unoperated shoulders.
Neuropathic Changes_duration
Time frame: one year post surgery
The EMG Examination will be performed on the muscles in both operated and unoperated shoulders to look for the presence or absence of neuropathic changes assessed by examining unit morphology: duration measured in milliseconds.
Neuropathic Changes_duration
Time frame: two year post surgery
The EMG Examination will be performed on the muscles in both operated and unoperated shoulders to look for the presence or absence of neuropathic changes assessed by examining unit morphology: duration measured in milliseconds.
Total number of Muscles affected with active denervation
Time frame: one year post surgery
The EMG Examination will be performed to look for abnormal changes as indicated by presence of active nerve denervation across the 5 muscles (upper subscapularis, Infraspinatus, Supraspinatus, teres minor, Rhomboid) in both operated and unoperated shoulders.
Total number of Muscles affected with active denervation
Time frame: two year post surgery
The EMG Examination will be performed to look for abnormal changes as indicated by presence of active nerve denervation across the 5 muscles (upper subscapularis, Infraspinatus, Supraspinatus, teres minor, Rhomboid) in both operated and unoperated shoulders.
Total number of muscles affected with neuropathic changes
Time frame: one year post surgery
The EMG Examination will be performed to look for neuropathic changes as indicated by amplitude, recruitment pattern and duration across the 5 muscles (upper subscapularis, Infraspinatus, Supraspinatus, teres minor, Rhomboid) in both operated and unoperated shoulders.
Total number of muscles affected with neuropathic changes
Time frame: two year post surgery
The EMG Examination will be performed to look for neuropathic changes as indicated by amplitude, recruitment pattern and duration across the 5 muscles (upper subscapularis, Infraspinatus, Supraspinatus, teres minor, Rhomboid) in both operated and unoperated shoulders.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- age \>45yrs
- primary diagnosis of osteoarthritis of the shoulder
- total shoulder replacement performed by Dr. Armstrong
- administered a local anesthetic mixture and not regional anesthesia
- all genders
- Fluent in written and spoken English
- Patients capable of giving informed consent
Exclusion criteria
- Known contraindications to CT/EMG
- Inability to provide informed consent
- History of recent trauma to the shoulder
- Atypical shoulder pain
- Other suspected shoulder pathology (i.e. tumor, infection)
- Bilateral total shoulder arthroplasty
Where
- Hershey, Pennsylvania
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 5, 2026 · Source of record for eligibility and locations