TSA v RSA in Osteoarthritic Shoulders With Greater Than 15 Degrees of Retroversion

Study Evaluating Reverse Versus Anatomic Total Shoulder Arthroplasty in Shoulders With Greater Than 15 Degrees of Retroversion in the Treatment of Osteoarthritis: Protocol

This study will compare total shoulder arthroplasty (TSA) with an augmented glenoid component and reverse shoulder arthroplasty (RSA) procedures, in participants with advanced glenohumeral osteoarthritis aged 65 years and older, who also present with greater than 15 degrees of glenoid retroversion, in the context of a prospective, randomized controlled trial to determine the optimal treatment in this patient population.

Osteoarthritis (OA) of the shoulder or glenohumeral joint, is a disease resulting from the wearing down of cartilage over time. OA can be the cause of pain and dysfunction and is a growing occurrence in our aging population. Total shoulder arthroplasty (TSA) or Reverse shoulder arthroplasty (RSA) are common surgical procedures used to treat patients with glenohumeral OA. TSA involves replacing the worn-out ball and socket glenohumeral joint with prosthetic components. TSA is performed today with high success rates, however, complication rates associated with TSA remain prevalent, particularly when the OA is associated with bone erosion on the glenoid (socket). An additional surgical technique using an "augmented glenoid component" has been developed to address this issue of missing bone. This technique attempts to realign and restore balance to the shoulder joint using artificial components and is also being performed as standard of care.

RSA is an alternative surgical procedure involves replacing and reversing the ball and the socket (i.e. opposite of TSA). RSA is typically performed in patients with a rotator cuff deficiency and more severe OA. Though RSA procedures show marked increase in clinical and functional outcomes, evidence of its long-term results are sparse, and as such is typically reserved for when treating an older patient population.

Few research studies have compared these different surgical techniques in older population and those with a more advanced level of OA degeneration. Previous studies have been limited to case series with small sample sizes and respective designs.

This research will provide surgeons with new information regarding the best treatment for this patient population.

This randomized controlled trial (RCT) will compare TSA + augmented glenoid component and RSA procedures to determine which approach produces better functional outcomes and quality of life in those with advanced OA who are in older patient population (65 years and older).

Primary Objective: Determine the difference in disease specific quality of life between patients diagnosed with glenohumeral OA who present with greater than 15 degrees (-15.1, -17, -20…etc.) of glenoid retroversion and undergo either a TSA + augmented glenoid component or RSA as measured by the WOOS score at 24-months and 5-years post-operative.

Secondary Objectives: i) Determine the difference in disease specific quality of life between patients diagnosed with glenohumeral OA who present with greater than 15 degrees of glenoid retroversion, and undergo a either a TSA + augmented glenoid component or RSA as measured by the Constant score, the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment form (ASES), EuroQol Group EQ-5D-5L, pain Visual Analog Scale (VAS), and Subjective Shoulder Value (SSV) scores at 24-months and 5-years post-operative, as well as adverse events, and health care utilization.

ii) Determine the survivorship of the components as measured by the degree of radiographic lucencies and component alignment determined by a CT scan at 1- and 5-years post-surgery.

Clinical Relevance: Glenohumeral OA results in pain and dysfunction, which negatively impacts quality of life. As such, determination of superior treatment approach will lead to significant improvement in quality of life, and cost savings through avoidance of recurrence and/or reoperation, as well as decreased morbidity for patients in this population.

Inclusion Criteria:

1. Diagnosis of idiopathic shoulder OA.
2. Patients who have failed standard non-surgical management of their shoulder OA who would benefit from a shoulder arthroplasty. Failed medical management will be defined as persistent pain and disability despite adequate standard non-operative management for at least 6 months. Medical management will be defined as: a) The use of drugs including analgesics and nonsteroidal anti-inflammatory drugs, b) Physiotherapy consisting of stretching, strengthening and local modalities (ultrasound, cryotherapy, etc.), c) Activity modification
3. Imaging, and intra-operative findings confirming advanced glenohumeral cartilage loss
4. Patients with a glenoid deficiency and >15 degrees of glenoid retroversion up to a maximum of 26 degrees of glenoid retroversion (i.e. -15.1, -17, -20…etc.)
5. 65 years of age and older

Exclusion Criteria:

1. Active joint or systemic infection
2. Rotator cuff arthropathy
3. Significant muscle paralysis
4. Charcot's arthropathy
5. Major medical illness (life expectancy less than 1 year or unacceptably high operative risk)
6. Unable to understand the consent form/process
7. Pregnancy
8. Psychiatric illness that precludes informed consent
9. Unwilling to be followed for the duration of the study
10. Retroversion cannot be surgically corrected to within 10 degrees of neutral
11. History of previous shoulder surgery on affected side
12. Rheumatoid arthritis in the affected shoulder