The information you supply is not specific enough to understand if surgery will be helpful (or even needed). I assume that your PLIF (fusion) of L5-S1 was successful (no pseudoarthrosis) and the nerve was adequately decompressed. Did you gain relief of leg and back pain from that surgery? Full relief or partial relief? Did the symptoms change after surgery?
Detection of nerve damage by EMG might be helpful. What nerve (or nerves) were detected to be injured? Did this EMG point out partial recovery or continuing denervation? Which nerves?
Retrolysthesis by itself is just an indicator of degenerative disc disease. This might or might not help to indicate back or leg pain.
See the section “how to describe symptoms” to better understand how to describe what you are experiencing. A synopsis of the MRI, X-ray and CT scan finding would be helpful.
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.