You have had the isthmic spondylolisthesis since you were about 10 years old most likely. This disorder has been quiescent until you tore some of the restraining scar tissue 7 years ago replacing that fence post. In many cases unfortunately, once the spondylo becomes painful, you can’t put the genie back into the bottle. Februrary of this year with that slip, more of the pannus tore (see website under isthmic spondylolisthesis to understand this concept).
Rheumatoid arthritis does occasionally affect the facet joints but less commonly in the lumbar spine. Interestingly in your case, the facets at L5-S1 are not loaded due to the pars fracture from the spondylolisthesis. It would be very rare to have facet pain from the L5-S1 segment even if these facets were involved with rheumatoid arthritis.
The chance of further slippage is highly unlikely in your case. Your disc at L5-S1 is very degenerative which almost “interlocks” L5 to the S1 segment. (Radiologist; “At L5-S1 severe disk space narrowing’).
I think there are occasions where waiting for surgery is a good idea but at your age with your diagnosis and history, this is not one of them. I agree that you would be healthier now than in 5 years and with your history of 7 years of pain, this condition is unlikely to improve.
You need a workup to determine the pain generator but I think based upon your limited history and MRI findings, the most likely pain generator is going to be the L5-S1 level. If that is the case, you would do well with a TLIF fusion of that level. See the website for further details of that procedure.
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.