Comparing The Outcome of Large-Diameter vs Small-Diameter Glenospheres in Primary Reverse Shoulder Arthroplasty

Study Overview
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Brief Summary
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The study will compare the outcome of primary reverse shoulder arthroplasty using the Stryker ReUnion System with implantation of either a large (40 mm) or a small (36 mm) glenosphere with either a +2 mm or a +6 mm offset.

Detailed Description
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A total of 220 shoulders will be included in the study (55 shoulders in each of the four groups). Each shoulder will be assessed preoperatively, at 3 weeks, 3 months, one year, two years and five years. The primary end-point will be range of motion at one year. Additional end-points will include dislocation, stress fractures of the acromion, metal ion levels in peripheral blood, neurovascular complications, radiographic notching, implant mechanical failure and revision surgery.

Official Title
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A Prospective, Randomized Study Comparing The Outcome of Large-Diameter vs Small-Diameter Glenospheres in Primary Reverse Shoulder Arthroplasty Using the ReUnion System

Conditions
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Glenohumeral Joint Degeneration

Intervention / Treatment
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* Device: ReUnion System with a Large-Diameter Glenosphere +2 mm offset
* Device: ReUnion System with a Small-Diameter Glenosphere +2 mm offset
* Device: ReUnion System with a Large-Diameter Glenosphere +6 mm offset
* Device: ReUnion System with a Small-Diameter Glenosphere +6 mm offset


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects willing to sign the informed consent Male and non-pregnant female subjects ages 50 - 90 at the time of surgery Subjects requiring a primary reverse total shoulder arthroplasty Subjects with the diagnosis of cuff-tear arthropathy (CTA), massive irreparable rotator cuff tear (MRCT) or osteoarthritis (OA) with marked posterior subluxation or bone loss Exclusion Criteria: Inability to comply with follow-up requirements Subjects with inflammatory arthritis Subjects with proximal humerus fractures Subjects with sequels of trauma Subjects that are immunologically compromised Subjects with an active or suspected latent infection in or about the shoulder Need to add a tendon transfer Need for structural humeral bone graft Pregnant subjects

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Large-Diameter Glenosphere +2 mm offset<br>Primary Reverse Shoulder Arthroplasty using the ReUnion System with a Large-Diameter Glenosphere +2 mm offset | Device: ReUnion System with a Large-Diameter Glenosphere +2 mm offset<br>* Primary Reverse Shoulder Arthroplasty using the ReUnion System with a Large-Diameter Glenosphere +2 mm offset<br>|
| Active Comparator: Small-Diameter Glenosphere +2 mm offset<br>Primary Reverse Shoulder Arthroplasty using the ReUnion System with a Small-Diameter Glenosphere +2 mm offset | Device: ReUnion System with a Small-Diameter Glenosphere +2 mm offset<br>* Primary Reverse Shoulder Arthroplasty using the ReUnion System with a Small-Diameter Glenosphere +2 mm offset<br>|
| Active Comparator: Large-Diameter Glenosphere +6 mm offset<br>Primary Reverse Shoulder Arthroplasty using the ReUnion System with a Large-Diameter Glenosphere +6 mm offset | Device: ReUnion System with a Large-Diameter Glenosphere +6 mm offset<br>* Primary Reverse Shoulder Arthroplasty using the ReUnion System with a Large-Diameter Glenosphere +6 mm offset<br>|
| Active Comparator: Small-Diameter Glenosphere +6 mm offset<br>Primary Reverse Shoulder Arthroplasty using the ReUnion System with a Small-Diameter Glenosphere +6 mm offset | Device: ReUnion System with a Small-Diameter Glenosphere +6 mm offset<br>* Primary Reverse Shoulder Arthroplasty using the ReUnion System with a Small-Diameter Glenosphere +6 mm offset<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Shoulder range of motion | The primary outcome will be shoulder range of motion in elevation, external rotation, and internal rotation. | One year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxford Shoulder Score questionnaire | The analysis will focus on comparing the subjects randomized to the small glenosphere to the patients randomized to the large glenosphere. | One year | 
| American Shoulder and Elbow Surgeons (ASES) scale | The analysis will focus on comparing the subjects randomized to the small glenosphere to the patients randomized to the large glenosphere. | One year | 
| Quick-DASH questionnaire | The analysis will focus on comparing the subjects randomized to the small glenosphere to the patients randomized to the large glenosphere. | One year |