Howdy compadres, I've been diagnosed with degenerative osteo art. in my neck, and lumbar, and hands and both knees. Four years ago I was so bad that I spent three month in bed, I couldn't even walk. Every time I stood or tried to move, it felt like my legs were being electrocuted from the waist down. Sean, keep up the mild exercise, it helps. I haven't tried inversion, but I think it wont hurt. I am on a morphine pain managment routine, and dont recommend it to anyone. I also recommend you do not take any of the other drugs, like celebrex, or neuronton, Mild physical therapy(you are on the right track)and find a really good surgeon are for you. The medicos have developed some new replacment discs, but they cannot guarantee relief, besides, surgery is the absolute last resort.
My deepest and most heartfelt sympathies to you, I know all to well how you feel and what you are going through.
At this point I will pray for our members in this group, and the ones I know of who haven't (yet), as I feel it works.