I certainly understand your concern with the osteoporosis but remember that once a person gets down to a very low dosage of prednisone, the side effects are also very minimal if any. When I first got down to a 3 mg prednisone dose, my rheumy commented that now I was down to the range where the prednisone was enough to keep the PMR and inflammation "asleep" but the 3 mg wasn't enough to truly cause or impact any side effects. He said if I had to take 3 mg daily or less for the rest of my life to keep the PMR under control he was fine with it because now I was at the level where the only effect from 3 mg was with the PMR - really nothing else. If you can be at a low level of prednisone I wouldn't worry that it's going to make the Osteoporosis worse. If you do decide to start taking Fosamax or similar drugs for Osteo, consider if you may have any heavy dental work in the future. That's the one risk but you'll want to read up on it.
Going back to your original comments, I do understand what you're saying as I am classified with Osteopenia but what matters to me most is keeping the pain and inflammation under control so I can have a reasonably good quality of life. If I'm hurting constantly, there is no quality of life.