Re: scar tissue
I'm glad to hear you have an appointment with your surgeon. As much as imaging can reveal, it does not show everything. It may turn out that you have something other than scar tissue compressing the nerve/nerves.
My leg pain was not resolved after my first fusion. For two years I was told it was scar tissue. My two surgeons, the one who performed the fusion, and the one I would eventually go to, both told me there were no surgical options, that it might be as good as it was going to get, and that I should learn to live with it. I was told to investigate a spinal cord stimulator.
I was convinced I had a mechanical reason for my pain so I keep pursuing other opinions. I'll spare you the details, but eventually I had another surgery. The surgeon was shocked what he found when he opened me up. Almost all my problems were coming from a segment that we all thought was only slightly "bad." The facet joints had deteriorated to the point that they were just little nubs, which allowied my spine to move in ways it was not designed to move...resulting in nerve compression. In reality I had very little scar tissue and what was there was not affecting the nerves. None of this was evident from all the imaging I had. My surgeon ended up having to perform major reconstructive surgery at L3-4 when we all thought my issues were at L5-S1...and yes, this was one of the surgeon's who initially thought my problems were stemming from scar tissue and permanent nerve damage.
My point is that even the best surgeons cannot always tell what's going on until he actually gets in there. I think you are wise to continue to look for answers...and, I hope you get them at your upcoming appointment.