How succsessful is treatment for DEGENERATIVE DISC DISEASE?

I have a 7 year old Rottweiler that was diagnosed with Degenerative Disc Disease. After being put on a couple different medication she seemed to be doing better and we were able to take her off the meds. Now 4 months later she is having pain again. We put her back on her meds but she is still having pain. The vet has now prescribed Tramadol and Prednisone. And now after 2 days on it she is still in pain. I called the vet again and they said if she is still in pain after the weekend to give them a call of what they can do next. Ive been reading online on the stages and I think she is still at stage 2 but Im very afraid stage 3 is coming soon. We keep her confined to a small area in the house and she just goes out to go potty. Im looking for answers of whats going on and whats going to happen next. I know surgery is also a option but I don't know at what point we need to think of that.