You may want to get that "gravel in your shoulder" checked out if you haven't already. If in fact you do have "gravel", or loose bodies as we call them, floating around inyour jointthey will grind your remaining cartilage away at a rapid speed. Another cause of OA is a disorder called synovial chondromatosis, which produces loose bodies that detach from the synovium and can cause a secondary OA. This is rarer than loose bodies that are a consequence of pre existing OA though. Loose bodies from any cause are bad. At any rate, it sounds like your Doc has got you pretty well covered based on your meds, and is probably aware of your situation.