Migration and Functional Outcome of DELTA Xtend Reverse Shoulder Lateralized Glenosphere Line Extension System

Study Overview
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Brief Summary
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This is a randomized controlled trial comparing the DELTA Xtend Reverse Shoulder System Lateralized Glenosphere Line Extension (intervention group) with the standard DELTA Xtend Reverse Shoulder System (control group). All Danish citizens with rotator cuff arthropathy or degeneration of the glenohumeral joint with severe posterior wear indicating a reverse total shoulder arthroplasty referred to the orthopedic department at Herlev and Gentofte Hospital, Copenhagen University Hospital will be considered for participation in the trial. The following exclude from participation in the study: Below 50 years of age; Cognitive or linguistic impairment; insufficient glenoid bone stock; previous fracture in the upper extremities; autoimmune mediated inflammatory arthritis.A total of 122 patients will be included of which 56 will be part of the roentgen radiostereometric analysis. This will allow a maximum of 20% drop out. The primary outcome is magnitude and pattern of migration of the glenoid component and functional outcome by Western Ontario Osteoarthritis of the Shoulder Index (WOOS score). The secondary outcomes are position of arthroplasty, loosening, inferior scapular notching, patient-reported outcomes, functional outcome, readmission, complications, revisions, changes in bone mineral density of the proximal humerus assessed by duel energy x-ray absorptiometry and economy (cost utility analysis). The patients are examined before the operation and 1 week and 3, 6, 12 and 24 months after the operation.

Official Title
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Migration and Functional Outcome of DELTA Xtend Reverse Shoulder Lateralized Glenosphere Line Extension System

Conditions
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Rotator Cuff Arthropathy or Degeneration of the Glenohumeral Joint With Severe Posterior Wear

Intervention / Treatment
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* Procedure: Reverse shoulder arthroplsaty


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Rotator cuff arthropathy defined as degeneration of the glenohumeral joint and wear or tear of at least one rotator cuff tendon Degeneration of the glenohumeral joint with intact rotator cuff function but severe posterior wear of the glenoid (>20 degrees posterior wear) Insufficient effect of non-surgical treatment with symptoms severe enough to justify shoulder arthroplasty. ASA (American Society of Anesthesiology) score 1-3, physically fit for surgery and rehabilitation Exclusion Criteria: Below 50 years of age Cognitive or linguistic impairment Insufficient glenoid bone-stock Previous fracture in the upper extremities Patients with autoimmune mediated inflammatory arthritis Glenoid border medial to the medial border of the coracoid on a true AP radiograph

Ages Eligible for Study
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Minimum Age: 50 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
Interventional Model Description: Based on the sample calculation the investigators intend to include a total number of 122 patients of which the first 56 patients will be studied using MB-RSA and DXA. The patients are allocated into two groups of equal of size: DELTA Xtend Reverse Shoulder System Lateralized Glenosphere Line Extension (intervention group) Standard DELTA Xtend Reverse Shoulder System (control group).
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: DELTA Xtend Reverse Shoulder System Lateralized Glenosphere Line Extension<br>By using a lateralized glensphere complications can be reduced and patients can achieve an improved outcome. Currently, little is known about the results of the lateralized design. The initial results have been promising, but migration and eventually loosening of the prosthesis can lead to poor results and, in some cases, revision | Procedure: Reverse shoulder arthroplsaty<br>* Patients with the diagnosis of rotator cuff arthropathy (degeneration of the glenohumeral joint and wear or tear of at least one rotator cuff tendon) or degeneration of the glenohumeral joint with severe posterior wear with an indication of a reverse total shoulder arthroplasty<br>|
| Active Comparator: Standard DELTA Xtend Reverse Shoulder System<br>A design with a standard glenosphere is currently regarded as the standard treatment | Procedure: Reverse shoulder arthroplsaty<br>* Patients with the diagnosis of rotator cuff arthropathy (degeneration of the glenohumeral joint and wear or tear of at least one rotator cuff tendon) or degeneration of the glenohumeral joint with severe posterior wear with an indication of a reverse total shoulder arthroplasty<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Radiostereometric analysis (RSA) [ Time Frame: Change from 1 week postoperatively to 3 months, 6 months, and at 1 and 2 years postoperatively ] | A special x-ray examination technique based upon insertion of small metal beads into the bone surrounding an implant and attachment of beads to the prosthesis (or using 3-dimensional models of the implant (CAD models) = model-based RSA (MB-RSA)). In this way, implant migration can be measured extremely accurate. | At 1 week and at 3 months, 6 months, 1 year and 2 years | 
| Western Ontario Osteoarthritis of the Shoulder index (WOOS) [ Time Frame: Change in WOOS score from preoperatively to 3 months, 6 months, and at 1 and 2 years postoperatively ] | The WOOS is a disease-specific patient-reported outcome (Lo IK et al 2001). There are 19 questions divided into four domains: Physical symptoms, sports and work, lifestyle and emotions. Each question is answered on a visual analogue scale ranging from 0 to 100. The overall score ranges from 0 to 1900, with 1900 being the worst. For ease of interpretation, the scores are converted to a percentage of the maximum score. There will be used a Danish version of WOOS (Rasmussen JV et al 2013) which was translated according to the guidelines of Guillemin, Bombardier and Beaton (Guillemin F et al 1993). It was validated with classical test theory in a cohort of patients treated with shoulder arthroplasty for osteoarthritis. | preoperatively and at at 3 months, 6 months, 1 year and 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plain radiographs [ Time Frame: Preoperatively and at 1 week, 3 months and at 1 and 2 years postoperatively ] | There will be used an anterior-posterior and a lateral view. The radiographs are used to evaluate the position of the component and to evaluate loosening as the cause of failure. | Preoperatively and at 1 week, 3 months and at 1 and 2 years postoperatively | 
| Duel energy x-ray absorptiometry (DXA) [ Time Frame: Preoperatively and at 1 week, 3 months, 6 months, and at 1 and 2 years postoperatively ] | Changes in bone mineral density (BMD) in close relation to an orthopedic implant can be measured by duel x-ray absorptiometry (DXA) | Preoperatively and at 1 week, 3 months, 6 months, and at 1 and 2 years postoperatively | 
| Constant-Murley score [ Time Frame: Preoperatively and 3 months, 6 months, and at 1 and 2 years postoperatively ] | The Constant-Murley Score includes an assessment of: pain; activities of daily living (ADL); range of motion; and strength. There are a possible 35 points given for the subjective assessment of pain and the ability to perform ADL. There are a possible 65 points given for an objective assessment, of which 40 points are allocated to range of motion and 25 points are allocated to strength. The maximum of 100 point indicates a shoulder with no disability. There will be used a Danish version (Ban I et al 2013) of the modified score described by Con¬stant and colleagues in 2008 (Constant CR et al 2008). | Preoperatively and 3 months, 6 months, and at 1 and 2 years postoperatively | 
| Oxford Shoulder Score (OSS) [ Time Frame: Preoperatively and 3 months, 6 months, and at 1 and 2 years postoperatively ] | Oxford Shoulder Score (OSS): The OSS was conceived as a measurement tool for the assessment of pain and function after elective shoulder surgery (Dawson J et al 1996). There are 12 questions with each item scored from 1-5. The overall score ranges from 12 to 60, with 60 being the worst. For ease of interpretation, the scores are converted to a percentage of the maximum score. There will be used a Danish version of OSS which was translated and validated with classical test theory (Frich LH et al 2011). | Preoperatively and 3 months, 6 months, and at 1 and 2 years postoperatively | 
| Side effects and complications [ Time Frame: 2 years postoperatively ] | There will be recorded any case of medical complications (embolism, cardiovascular event, pneumonia) and complications related to the surgical procedure (fractures, nerve injuries, deep and superficial infections, malpositioning of the components, instability, and dislocation) and revisions defined by removal or exchange of any component. | 2 years postoperatively | 
| Pain and patient-satisfaction: visual analogue scale (VAS) [ Time Frame: 3 months, 6 months, and at 1 and 2 years postoperatively ] | Pain is answered on a visual analogue scale (VAS) ranging from 0 to 10, with 10 being the worst. Patients are asked to categorize the result as excellent, very good, good, fair and poor. | 3 months, 6 months, and at 1 and 2 years postoperatively | 
| Cost-utility analysis [ Time Frame: 2 years postoperatively ] | In modern health economics, thresholds have been estimated for acceptable cost-utility ratios - the threshold for how much health care providers will pay for an extra quality- adjusted life year (QALY). In England and in Europe, the threshold for an extra QALY is set at 20,000-30,000 pounds and 30,000 Euros respectively. The cost utility of the Comprehensive Nano stemless shoulder arthroplasty will be compared with these thresholds and with the cost utility of the uncemented Comprehensive stemmed total shoulder arthroplasty. The EQ-5D will be used to estimate QALY for individual patients. | 2 years postoperatively |