Hi Georgia -
It's hard to give any insight to this without knowing exactly what the name of the procedure is - you can google: minimally invasive spinal surgery, and come up with lots of hits from different places etc.,
as far as some of the different procedures noted what I have found is:
1) If damage to a disc is minimal they will go in and shave off the area
2) If damage is slightly more or worse some of the "hardware" is very small, almost like spacers to put in around the disc and sometimes the "hardware" may be slightly bigger, but smaller than the "usual big hardware normally done with FUSION surgeries
3) Some hardware is put in at the facet joint(s) to help reduce pains
and yes, with most of the "minimally invasive spinal surgeries" the incisions are slight usually done with some small "holes"(enough for small tubes and/or to see where they are going) and a small incision so that the "hardware" can be inserted.
I can tell you that with my incision, Anterior Lumbar Fusion L5-S1 that mine starts at my belly button and goes down about 6 inches. As soon as my staples were removed the PA told me to rub the incision site especially any hard areas as this would help reduce the size of the scar. I also purchased some expensive cream that is supposed to help reduce the size of the scar. I rubbed and rubbed and even tough my surgery was in 2/08 my incision is a very faint pencil line. Remember too, the approach they did on me was from my stomach. I don't know but it seems the front may make a difference as it's harder to reach the backside to rub.
Anyway, hope this helps a little - take care Georgia~~