In my day job, I'm a professor of Biomedical Engineering with a specialization in biomaterials and surgical implant design. You know, we tend to think (these days) that joint replacements have become so commonplace that, aside from the cost and availability etc., there's always a good outcome. Well, that's pretty much true of hip replacments, mostly true of knee replacements, and much less true of other joints. The shoulder, for instance, is a really unconstrained joint—not at all like the ball-and-socket of the hip's "design"—formed where the humerus, scapula, and clavicle make a really improbable connection. This is probably the case since it was a relatively late evolutionary development after we came on land. The result is that designing a good replacement, and implementing that design surgically in a degenerated joint, is really a tough job. It's not surprising that the successful outcome rate, described in various ways but mostly in terms of pain and mobility, is much lower than it is for hips and knees. Patients are therefore often wise to work through whatever other therapeutic options may be availabe to retain adequate function before commiting to shoulder joint replacement, going forward only when (i) pain and lack of function become overwhelming and (ii) continuing degradation of the joint tissue may threaten promise of a successful surgical outcome. I don't know enough about your case to know where you are relative to those two criteria, although it seems your humeral head and cartilage may be completely shot. While you still have some function, it would be wise to explore every conservative approach you can manage until the surgical outcome is threatened. Surgeons are inherently optimistic presenters of the likely outcomes of their handiwork, so do take their advice with respectful caution. Get some advice if you can from sports/rehabilitation docs (physical medicine) and from physiotherapy, and of course stay away from non-scientific alternative therapists. Shoulder degeneration is common in late life athletes—particularly hockey players who repeatedly crush shoulders going into the boards—and the sports docs often have deep experience with this sort of thing. My $0.02.