In most cases, non-surgical treatment is successful in relieving the patient’s pain; if not, surgery can be considered.
A spinal fusion for spondylolisthesis is generally quite effective, but because it is a large surgery with a lot of recovery, it usually is not considered until a patient has failed six months of concerted non-surgical treatment.
Isthmic spondylolisthesis above the L5-S1 level is more likely to need surgery because of the amount of motion in the upper vertebral segments. It is less likely that a spondylolisthesis at L5-S1 will need surgery. However, because the incidence of spondylolisthesis is so much higher at L5-S1, most surgeries will still be at L5-S1.
The L5-S1 segment at the bottom of the spine is not a major motion segment as it is deep in the pelvis, and it is also not really designed to move much. This is an important point because if this level is fused, it does not transfer a lot of stress to the other levels of the spine.
After an L5-S1 fusion, the spine is still biomechanically much the same as it was preoperatively, and most patients will not perceive any difference in their motion after a one-level lumbar fusion.
Spinal Fusion Considerations for Spondylolisthesis
The preoperative workup will include X-rays and an MRI scan. Some physicians will also require a patient to undergo a discogram prior to a spinal fusion, although the usefulness of this study is still a matter of fierce debate among surgeons.
Some surgeons believe that discograms are a good indicator of whether or not disc space is a pain generator and can help determine the number of levels requiring a fusion. Other surgeons believe this study is far too subjective and lacks specificity and sensitivity.
Unfortunately, there is little literature that indicates whether or not a preoperative discogram leads to a more successful surgical outcome. A recent study by Carraggee in Spine indicated that discograms were predictive of a good outcome in only 50% of cases. Whether or not the study is used is more a matter of philosophical bias than true science.