Are you the same patient I have been discussing this problem with before? If so, you have the significant degenerative disc with severe pain reproduction at L5-S1, a non-painful disc at L4-5 and an anterior tear with moderate pain reproduction at L3-4.
If that is the case, be very careful of a three level fusion. If this were my back, I would consider an L5-S1 fusion only and see how it would go. The L4-5 disc was not painful and I would resist having that level fused. The L3-4 disc had an anterior annular tear but the back of the disc was intact.
Again, if you are the same individual I talked with before, the anterior tears in the discs are normally not severe pain generators and I would try to live with the L3-4 disc. I have had a number of patients in your situation and most of them are reasonably satisfied with a one level fusion at L5-S1.
Dr. Corenman