That's a question you and your doctor will have to answer together. But when shoulder pain interferes with the things you want or need to do, the time may be right.
Shoulder replacement may be an option when nonsurgical interventions such as medication and physical therapy no longer help alleviate the persistent pain. Other possible signs such as: aching in the joint, followed by periods of relative relief, pain after extensive use, loss of motion, joint stiffness after periods of inactivity or rest, and/or pain that seems to increase in humid weather may also lead you and your doctor to consider a shoulder replacement.
Your primary care doctor may refer you to an orthopedic surgeon who will help you determine when or if it's time for shoulder surgery and which type of shoulder surgery is most appropriate. Your surgeon may decide that shoulder replacement surgery is not appropriate if you have an infection, you do not have enough bone, or the bone is not strong enough to support an artificial shoulder.
Doctors generally try to delay total shoulder replacement for as long as possible in favor of less invasive treatments. However, if you have advanced joint disease, you may evaluate with your doctor if a shoulder replacement offers the chance for relief from pain and a return to normal activities.