Yes I had exactly what your talking about. My Doc called condition Flat Back Syndrome. You should look it up. The procedure I had is called an Osteotomy.
They removed all old hardware, put a wedge in disk L3, and fused me from T-12 to S-1. I won't lie to you, the surgery was HERENDOUS but it gave me my life back. I was pretty much a cripple by the time I had it done. I hate to tell you this, but you will only get worse if you don't get it fixed. Did they use a Harrington Rod with your first surgery? They believe that is what caused my flat back. As I said the surgery sucked big time, but if it would get rid of my neuropathy I would do it every year. I had mine done in 2006 and I can tell you that my back has been a non issue ever since. Your in luck to have one of the best surgeons because your going to need one. I wish you the best of luck.