It is obvious that you need a redo fusion at L4-5. This should include a TLIF to have a good chance of solid fusion.
I am unclear why you need a fusion at L5-S1. The information given (“L5-S1: There is 1 to 2 mm retrolisthesis of L5 with mild broad disc bulge and endplate spurring mildly narrowing the neural foramina bilaterally”) does not implicate this level as causing nerve or caudal equina compression. You do have a degenerative disc but this does not mean that this level is causing back pain necessarily. Further work-up could be performed with a discogram if there is concern that this level is causing pain and needs to be addressed surgically.
The levels above the fusion are all degenerative. I am unclear as to the reason why L3-4 needs a fusion as all the levels above the L4-5 level could be (or not) causing lower back pain.
My worry is that with your current plan, you will have a three level fusion with degenerative discs above. Be very careful with this revision surgical plan.
Dr. Corenman
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.