Catalyst CSR Shoulder System for Semi or Total Shoulder Arthroplasty

This study is evaluating the safety and performance of the Catalyst CSR Shoulder System — an implant used in partial or total shoulder replacement surgery — in people with serious shoulder joint disease. **You may be eligible if...** - You are 18 years or older with fully developed bones - You have degenerative disease of the shoulder joint (such as osteoarthritis or rotator cuff arthropathy) that your doctor has determined requires a shoulder replacement - Your condition matches the approved uses for this specific implant system - You speak English **You may NOT be eligible if...** - You have had open (non-arthroscopic) surgery on the same shoulder before - You have a full-thickness rotator cuff tear or significant bone wear at the back of the shoulder socket - You are unwilling or unable to attend follow-up visits or complete the required assessments - Your doctor believes participation is not in your best interest Talk to your doctor to see if this trial is right for you.