I wouldn’t focus too much on Bertolotti Syndrome as even when present, it rarely is a pain generator. When it is painful, both resection and/or fusion of L5-S1 resolves the pain generation, both of which you have had (fusion multiple times-hopefully it is solid). If L5-S1 is not solidly fused, that needs to be addressed surgically. Bertolotti Syndrome, once resected does not regrow but maybe the resection was incomplete. Nonetheless, you have had fusion of L5-S1 which is the definitive treatment. The ADRs at L3-5 could be pain generators but the only way to really know is to fuse these levels and there is no guarantees of success. L2-3 sounds like it has broken down (ASD) but you have had so much unsuccessful lumbar surgery that I would be very careful to engage surgeon’s services again for that.
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.