You have a congenital fusion of L3-4. The spondylolisthesis at L4-5 might be a response to this fusion (stress loading).
Catastrophic failure would be a tear under load of the remaining L4-5 disc tissues and secondary scar restraints (the fibrous pars attempt at repair). This tearing would allow a translation of the L4 on the L5 vertebrae and compression of the exiting nerve roots. Also possible is a compression of the cauda equina with a large translation.
There is not a huge difference fixing a grade two vs. a grade three slip but the reduction of slip would be less with a grade three slip. You probably would not be able to tell the difference but in measurement, the corrected sagittal alignment would be worse with a surgery to correct a grade three slip.
Dr. Corenman
PLEASE REMEMBER, THIS FORUM IS MEANT TO PROVIDE GENERAL INFORMATION ON SPINE ANATOMY, CONDITIONS AND TREATMENTS. TO GET AN ACCURATE DIAGNOSIS, YOU MUST VISIT A QUALIFIED PROFESSIONAL IN PERSON.
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.
