Typically, isthmic spondylolisthesis pain is not migratory pain. The pain develops from the pannus at the pars defect, the torn disc or the nerve (or all three). Why your pain migrates could be from any of the three at the time of activity being aggravated but you cannot hang your hat on that.
Discal pain causes central lower back pain. “Trimming” the disc will reduce any existing compression of the nerves but only infrequently reduces lower back pain itself.
If you are going to consider surgery, the next test that I would do would be a discogram. Understand that there is a 90% chance that this will reveal the pain generator but there is a 10% chance that it would rule you out for surgery.
I have a new section on the website under “Treatment”; “When to have lower back surgery”. Read that to see if you if in any of the categories.
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.