You need to separate your symptoms by percentage into lower back and buttocks/thigh/leg pain. The difference in percentage may indicate the need for different surgeries. If most of your pain is from the buttocks/thigh/leg region, you might be able to undergo a simple microdisectomy. If the symptoms are more heavily weighted to the lower back, a fusion might need to be included in any surgery.
I would think your treating physician would want a new MRI as your symptoms have changed.
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.