I would also get the physician who is managing your lupus to give an opinion on whether or not that condition rules you out as surgical back candidate.
In a prior profession, I handled injury claims for an insurance company. In the surgical back cases I managed, there were some that got better after surgery, some did not improve, and a few got worse. I felt the patient's motivation to get well along with the surgeon's skill had alot to do with the result.
Another recommendation: After the MRI, if the orthopedist feels surgery is indicated get a second opinion from another orthopedist from a different medical group and if possible one who works out of a different hospital. If I think of any other recommendations, I'll freepmail you a note.