You might be mistaken with your terminology. You note pars fractures of either L4 or L5 (or both which would be unusual). These fractures normally allow the vertebra above to slip forward which is called an anterolisthesis. This entire complex of fracture and forward slip is also called a spondylolisthesis. You can find a complete description on the website under lumbar spine conditions.
Before you consider surgery, you need to go through a complete rehabilitation program. Many patients improve and do not need to consider surgery. Surgery can be considered if you do not improve. See the section “when to have lower back surgery” to understand surgical indications.
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.