TSA vs RSA in Glenohumeral Osteoarthritis

Inclusion Criteria: 1. Patients who have failed standard non-surgical management of their idiopathic shoulder osteoarthritis 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 6 months. Medical management will be defined as: 1. The use of drugs including analgesics and non-steroidal anti-inflammatory drugs 2. Physiotherapy consisting of stretching, strengthening and local modalities (ultrasound, cryotherapy, etc.) 3. Activity modification 2. Imaging, and intra-operative findings confirming advanced glenohumeral cartilage loss 3. Patients may present with a glenoid deficiency and \</=15 degrees of retroversion 4. 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