I had a Micro distectomy several years ago for a L4-L5 disc that had ruptured. Since that time i have noticed some Sciatica and occasionally some tingling only in my left leg. My back started hurting pretty bad also. What i noticed now after two full seasons since the operation is that when I ride more often and regular the pain in the back gradually goes away as my core gets stronger. . I am an old guy (56) and I ride a giant defy advanced 0 which is a fast endurance style road bike that has a slightly higher handle bars and I run them about 1" below my saddle height. When i start riding less my back hurts more and sciatica get some worse.

As far as the saddle is concerned, what I noticed is that I need to ride my saddle with the nose pointed down about 5 degrees to tilt my pelvis forward when i am riding. I also use clip on aero bars to change up my riding position especially when I am going on longer rides (>40 miles). A very hard flat saddle also works best for me as long as its tilted down some. Just my personal experience.