Conventional wisdom says that patients with known spinal stenosis, and associated spondylolisthesis should have fusion if having decompression surgery. The often quoted 1991 paper from Herkowitz and Kurz identified a clinical advantage to perform lumbar fusion for patients undergoing laminectomy for spondylolisthesis with lumbar stenosis.
Much research has been geared towards the types of fusions that would give better results with less painful recovery.
Since the 1991 paper, there has been some advances in the types of surgery performed. Some groups are starting to challenge the need for fusion while decompressing the stenosis area of the spine.
Certain principles of spinal stability are based on the competence of muscles and ligaments of the spine. Much research has show the benefits of the intact multifidus muscles, and tendons. Other research have show that orientation of the facet joints may have bearing on the development of spinal instability.
With targeted decompression, and preservation of some of the ligaments, not all the stabilizing structures need to be removed.
In the face of a relatively static spondylolisthesis, some have theorized that stability could be maintained while decompressing the spondylolithesis related central and lateral recess stenosis. Fusion may not be necessary.
In March of 2014, Chang et al reported no worsening outcome for decompression only surgery for spondylolithesis related spinal stenosis patients. The technique utilized a unilateral laminotomy with a bilateral decompression.
Other studies have identified that a significant number of spine surgeons are avoid lumbar fusion, and decompressing only, despite the presence of spondylolisthesis for select patients.
From my perspective, lumbar spinal fusion has certainly seen an increase of utilization. The added risks, costs, and complications make the lumbar fusion recommendation a difficult one for certain patients. More studies need to be done to identify situations by which a fusion may not be necessary when also decompressing a patient with spondylolithesis. The orginal studies by Herkowitz, and Kurz was based on older 1980’s techniques and technologies. Perhaps spine surgery has developed so we can be more targeted in selecting those we fuse, and not fuse.