Cuff Tear ArthropathyEMGRTSANCT07464977
EMG and Delta Function in Standard RTSA vs Lateralization
A study testing Lateralization of glenoid component and Standard implantation technique in people with Cuff Tear Arthropathy and Omarthrosis, run by Vienna Hospital Association at 1 site in Austria.
Trial summary
Reverse total shoulder arthroplasty (RTSA) is a well-established method to treat patients with irreparable rotator cuff tears and glenohumeral osteoarthritis. The biomechanical principle implies a medialization and distalization of the center of rotation (COR). Read more about this study
- Who is it for?
- Ages 60 to 85 years
- Conditions the study is for
- Cuff Tear Arthropathy, Omarthrosis, Rotator Cuff Tear Arthropathy
- What is being tested?
- Lateralization of glenoid component and Standard implantation technique
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 130 participants
- Where
- 1 siteAustria
- Study dates
- Jun 2026to Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 60 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- male/female, 60-85y
- diagnosis of Cuff tear arthropathy (CTA)
- irreparable rotator cuff tear
- severe osteoarthritis (OA)
- primary RSA
- verified rotator cuff tear in preoperative MRI
- absence of severe cognitive impairment
Who cannot join
- previous muscle transfer
- revision surgery
- highly dysplastic glenoid
- axillary nerve palsy
- upper limb radiculopathy
- cervical myelopathy
Show all 10Show fewer
- degenerative muscular disease,
- previous proximal humeral fracture
- revision arthroplasty
- rheumatoid arthritis
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Postoperative Deltoid EMG Activity and Function in Patients After Reverse Total Shoulder Arthroplasty: A Comparison of Standard Implantation Technique and Lateralization
Reverse total shoulder arthroplasty (RTSA) is a well-established method to treat patients with irreparable rotator cuff tears and glenohumeral osteoarthritis. The biomechanical principle implies a medialization and distalization of the center of rotation (COR). Deficiencies in internal and external rotation constitute frequently encountered functional problems. Some studies showed reduced activation of the posterior deltoid in EMG measurements, which may explain the inability to compensate these movements. Lateralized prosthetic designs demonstrated increased external rotation through an alteration of the deltoid's lever arm.
The aim of the study is to investigate the impact of lateralization on functional outcome and deltoid EMG activity in comparison to a standard implantation technique.
Read the detailed description
Introduction Reverse total shoulder arthroplasty (RTSA) is a well-established method to treat patients with irreparable rotator cuff tears and glenohumeral osteoarthritis. The biomechanical principle is a medialization and distalization of the center of rotation (COR) to provide a compensatory role for the insufficient rotator cuff. Deficiencies in internal and external shoulder rotation constitute frequently seen functional problems. Some studies showed reduced activation of the posterior deltoid in EMG measurements, which may explain the inability to compensate these movements. Lateralized prosthetic designs implants demonstrated increased external rotation force through an alteration of the deltoid's lever arm.
Material and Methods This study will be conducted as a monocentric randomized, prospective trial. Approximately 130 patients, scheduled for reversed total shoulder arthroplasty (RSA), will be enrolled. The patients will be divided into two groups depending on receiving RSA or a lateralized implant via randomization. Preoperatively and at 4 follow-up visits, a surface EMG (sEMG) of the deltoid muscle will be conducted and clinical scores (Constant-Murley Score and Quick DASH questionnaire) will be assessed. As patient related outcome measures, p-ASES-S and SVV will be evaluated. Pre- and postoperative x-rays and CT scans will be conducted for preoperative planning and measurement of achieved lateralization. Clinical and radiological complications will be routinely documented. Group comparisons and correlations will be performed to compare both groups pre- and postoperatively. The study's duration is scheduled for 2 years.
Aim of the Study The aim of the study is to evaluate a possible difference in function and EMG activity between the two patient groups. Especially a different increase in external rotation range of motion and strength shall be investigated. Furthermore a possible connection between preoperative deltoid muscle activity and postoperative outcome shall be pointed out. Lastly, the impact of lateralization on functional outcome, shall be evaluated compared to the standard implantation technique.
- Being tested
- Lateralization of glenoid component, Standard implantation technique
- Keywords
- reverse total shoulder arthroplasty, cuff tear arthropathy, lateralization, deltoid function, EMG
- Medical subject headings
- Rotator Cuff Tear Arthropathy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Lateralization of glenoid componentDevice
Lateralization of glenoid component in reverse total shoulder arthroplasty via metal augment on the glenoid side with a thickness of at least 4mm
Standard implantation techniqueDevice
Implantation of a standard glenoid component without any lateralization via metal back on the glenoid site
| Study group | Role | What they receive |
|---|---|---|
| Standard Implantation Group | Active comparator | Subjects treated with a standard glenoid component of the used reverse total shoulder prosthesis Receives: Device: Standard implantation technique |
| Lateralized Implantation Group | Active comparator | Subjects treated with a lateralized glenoid component of the used reverse total shoulder prosthesis Receives: Device: Lateralization of glenoid component |
What is being measured
The primary outcome is the main question the study is designed to answer.
Delta Muscle activity (especially posterior Delta part)
The ratio between peak torque and EMG root mean square is measured
Measured: preoperative
Delta Muscle activity (especially posterior Delta part)
The ratio between peak torque and EMG root mean square is measured
Measured: 6 weeks postoperative
Delta Muscle activity (especially posterior Delta part)
The ratio between peak torque and EMG root mean square is measured
Measured: 3 months postoperative
Delta Muscle activity (especially posterior Delta part)
The ratio between peak torque and EMG root mean square is measured
Measured: 6 months postoperative
Delta Muscle activity (especially posterior Delta part)
The ratio between peak torque and EMG root mean square is measured
Measured: 1 year postoperative
Secondary outcomes (11)
Range of movement (forward flexion, abduction, external rotation, extension)
ROM (range of movement) measured with a goniometer according to neutral zero method
Measured: preoperative
Range of movement (forward flexion, abduction, external rotation, extension)
ROM (range of movement) measured with a goniometer according to neutral zero method
Measured: 6 weeks postoperative
Range of movement (forward flexion, abduction, external rotation, extension)
ROM (range of movement) measured with a goniometer according to neutral zero method
Measured: 3 months postoperative
Range of movement (forward flexion, abduction, external rotation, extension)
ROM (range of movement) measured with a goniometer according to neutral zero method
Measured: 6 months postoperative
Range of movement (forward flexion, abduction, external rotation, extension)
ROM (range of movement) measured with a goniometer according to neutral zero method
Measured: 1 year postoperative
Objective and subjective outcome scores / Quality of life scores
Constant score (0-100) (higher = better)
Measured: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Objective and subjective outcome scores / Quality of life scores
SVV (subjective shoulder value) (0-100%) (higher = better)
Measured: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Objective and subjective outcome scores / Quality of life scores
p-ASES (patient-reported American Shoulder and Elbow Surgeons Score) (0-100) (higher = better)
Measured: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Objective and subjective outcome scores / Quality of life scores
Quick-DASH (Quick-Disability of Arm, Shoulder and Hand) (0-100) (higher = better)
Measured: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Difference in lateralization between preoperative 3D CT-based planning and postoperative CT-based implant position
Lateralization will be quantitatively assessed by comparing preoperative and postoperative computed tomography (CT) scans. The preoperative CT scan will be used for 3D planning and virtual implantation. The postoperative CT scan will be used to determine the actually achieved implant position.
The original preoperative joint line will serve as the reference value. Medialization or lateralization will be measured as the linear distance (in millimeters) between the preoperative joint line and the postoperative implant position. The achieved lateralization will be calculated based on this difference.
Additionally, the planned lateralization from the preoperative 3D virtual implantation will be compared with the actually achieved lateralization measured on the postoperative CT scan. The primary metric will be the absolute and mean deviation (in millimeters) between planned and achieved lateralization, allowing assessment of the accuracy of the preoperative 3D planning.
Measured: Preoperative and 1 year postoperative
Humeral Length (Millimeters) Measured on Standardized Radiographs
Humeral length will be measured in millimeters on standardized anteroposterior radiographs of the entire humerus obtained according to the Lädermann protocol. Measurements will be performed by comparing preoperative and postoperative radiographs. The primary metric will be the absolute difference in humeral length between preoperative and postoperative images. Measurements will be performed using calibrated digital imaging software by blinded reviewers.
Measured: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Mar 2026
- Study startJun 2026 (estimated)
- Primary completionAug 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cuff Tear ArthropathyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 130 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vienna Hospital Association
- Sponsor type
- Other government
- Responsible party
- Sponsor
- Investigators
- Robert Breuer, MD, Principal investigator, Vienna HA
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07464977
- Sponsor's protocol ID
- Protocol EMG RTSA 4.0
- Acronym
- EMGRTSA
- Status last verified
- May 2026
- First submitted
- 10 Aug 2024
- Last updated
- 7 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Postoperative Deltoid EMG Activity and Function in Patients After Reverse Total Shoulder Arthroplasty: A Comparison of Standard Implantation Technique and Lateralization
- ClinicalTrials.gov ID
- NCT07464977
- Acronym / sponsor ID
- EMGRTSA / Protocol EMG RTSA 4.0
- Keywords
- reverse total shoulder arthroplasty, cuff tear arthropathy, lateralization, deltoid function, EMG
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 130 participants (estimated)
- Lead sponsor
- Vienna Hospital AssociationOther government
- Study start
- Jun 2026 (estimated)
- Primary completion
- Aug 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 11 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Reverse total shoulder arthroplasty (RTSA) is a well-established method to treat patients with irreparable rotator cuff tears and glenohumeral osteoarthritis. The biomechanical principle implies a medialization and distalization of the center of rotation (COR). Deficiencies in internal and external rotation constitute frequently encountered functional problems. Some studies showed reduced activation of the posterior deltoid in EMG measurements, which may explain the inability to compensate these movements. Lateralized prosthetic designs demonstrated increased external rotation through an alteration of the deltoid's lever arm.
The aim of the study is to investigate the impact of lateralization on functional outcome and deltoid EMG activity in comparison to a standard implantation technique.
Detailed description
Introduction Reverse total shoulder arthroplasty (RTSA) is a well-established method to treat patients with irreparable rotator cuff tears and glenohumeral osteoarthritis. The biomechanical principle is a medialization and distalization of the center of rotation (COR) to provide a compensatory role for the insufficient rotator cuff. Deficiencies in internal and external shoulder rotation constitute frequently seen functional problems. Some studies showed reduced activation of the posterior deltoid in EMG measurements, which may explain the inability to compensate these movements. Lateralized prosthetic designs implants demonstrated increased external rotation force through an alteration of the deltoid's lever arm.
Material and Methods This study will be conducted as a monocentric randomized, prospective trial. Approximately 130 patients, scheduled for reversed total shoulder arthroplasty (RSA), will be enrolled. The patients will be divided into two groups depending on receiving RSA or a lateralized implant via randomization. Preoperatively and at 4 follow-up visits, a surface EMG (sEMG) of the deltoid muscle will be conducted and clinical scores (Constant-Murley Score and Quick DASH questionnaire) will be assessed. As patient related outcome measures, p-ASES-S and SVV will be evaluated. Pre- and postoperative x-rays and CT scans will be conducted for preoperative planning and measurement of achieved lateralization. Clinical and radiological complications will be routinely documented. Group comparisons and correlations will be performed to compare both groups pre- and postoperatively. The study's duration is scheduled for 2 years.
Aim of the Study The aim of the study is to evaluate a possible difference in function and EMG activity between the two patient groups. Especially a different increase in external rotation range of motion and strength shall be investigated. Furthermore a possible connection between preoperative deltoid muscle activity and postoperative outcome shall be pointed out. Lastly, the impact of lateralization on functional outcome, shall be evaluated compared to the standard implantation technique.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard Implantation Group | Active comparator | Device: Standard implantation techniqueSubjects treated with a standard glenoid component of the used reverse total shoulder prosthesis |
| Lateralized Implantation Group | Active comparator | Device: Lateralization of glenoid componentSubjects treated with a lateralized glenoid component of the used reverse total shoulder prosthesis |
Who may qualify
- Ages
- 60 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- male/female, 60-85y
- diagnosis of Cuff tear arthropathy (CTA)
- irreparable rotator cuff tear
- severe osteoarthritis (OA)
- primary RSA
Key exclusion criteria (10 listed)
- previous muscle transfer
- revision surgery
- highly dysplastic glenoid
- axillary nerve palsy
- upper limb radiculopathy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Lateralization of glenoid componentLateralization of glenoid component in reverse total shoulder arthroplasty via metal augment on the glenoid side with a thickness of at least 4mm | Device | Lateralized Implantation Group |
| Standard implantation techniqueImplantation of a standard glenoid component without any lateralization via metal back on the glenoid site | Device | Standard Implantation Group |
Primary outcome
Delta Muscle activity (especially posterior Delta part)
Time frame: preoperative
The ratio between peak torque and EMG root mean square is measured
Delta Muscle activity (especially posterior Delta part)
Time frame: 6 weeks postoperative
The ratio between peak torque and EMG root mean square is measured
Delta Muscle activity (especially posterior Delta part)
Time frame: 3 months postoperative
The ratio between peak torque and EMG root mean square is measured
Delta Muscle activity (especially posterior Delta part)
Time frame: 6 months postoperative
The ratio between peak torque and EMG root mean square is measured
Delta Muscle activity (especially posterior Delta part)
Time frame: 1 year postoperative
The ratio between peak torque and EMG root mean square is measured
11 secondary outcomes
Range of movement (forward flexion, abduction, external rotation, extension)
Time frame: preoperative
Range of movement (forward flexion, abduction, external rotation, extension)
Time frame: 6 weeks postoperative
Range of movement (forward flexion, abduction, external rotation, extension)
Time frame: 3 months postoperative
Range of movement (forward flexion, abduction, external rotation, extension)
Time frame: 6 months postoperative
Range of movement (forward flexion, abduction, external rotation, extension)
Time frame: 1 year postoperative
Objective and subjective outcome scores / Quality of life scores
Time frame: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Objective and subjective outcome scores / Quality of life scores
Time frame: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Objective and subjective outcome scores / Quality of life scores
Time frame: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Objective and subjective outcome scores / Quality of life scores
Time frame: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Difference in lateralization between preoperative 3D CT-based planning and postoperative CT-based implant position
Time frame: Preoperative and 1 year postoperative
Humeral Length (Millimeters) Measured on Standardized Radiographs
Time frame: preoperative, 6 weeks postoperative, 3 months postoperative, 6 months postoperative, 12 months postoperative
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 May 2026.
- Individual participant dataSharing planned: No
Related trials for Cuff Tear Arthropathy
Active, not recruiting
Lyophilized Platelet-Rich Plasma Lysate vs Dextrose Prolotherapy for Partial Rotator Cuff Tears
Rotator Cuff Tear, Rotator Cuff Syndrome
Active, not recruiting
Efficacy and Safety of Digital Therapeutics for Improving Shoulder Function After Rotator Cuff Repair
Rotator Cuff Tear Arthropathy, Repair of a Cuff Tear
RecruitingObservational study
Evaluating Hemidiaphragmatic Paralysis With Prolonged Neural Blockade From an Interscalene Brachial Plexus Block
Shoulder Surgery, Shoulder Pain
Enrolling by invitationPhase 1
Stem Cell Treatment for Regeneration of the Rotator Cuff (Lipo-Cuff Study)
Rotator Cuff Tears, Rotator Cuff Injuries
Enrolling by invitation
Patient Education and Sling Use After Shoulder Surgery
Rotator Cuff Tear, Sling
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Robert Breuer, MD principal investigator
Vienna HA
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Lateralization of glenoid component and Standard implantation technique in people with Cuff Tear Arthropathy and Omarthrosis, run by Vienna Hospital Association at 1 site in Austria.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 7 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Austria. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Robert Breuer, MD (00430128802 ext. 743429, robert.breuer@meduniwien.ac.at), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Delta Muscle activity (especially posterior Delta part) (time frame: preoperative). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 May 2026.