The symptoms provoked by lumbar spinal stenosis (LSS) range from none in up to 21% of the cases (1) to one or several of the following: neurogenic claudication, radicular pain, motor deficit, sensory alterations or deficit, and low back pain (LBP). Although often considered as a satellite or independent symptom not referred to, the latter is significant in up to 75% of the symptomatic cases of LSS.

It is generally agreed that the surgical decompression of the compromised neural structures is the adequate treatment if conservative methods have failed. Surgical decompression will cure or relieve peripheral symptoms and improve walking capacity in 60% to 90% of the cases (9). The therapeutical attitude regarding LBP remains a subject of controversy. Indications for fusion, with or without instrumentation, or stabilization by some nonrigid means, are still not well defined. Major instability demonstrated on dynamic radiographs, iatrogenic instability induced by facetectomy or discectomy, as well as degenerative spondylolisthesis are admitted indications for fusion. The presence of LBP, disc degeneration, stable spondylolisthesis, and degenerative scoliosis are further situations that may lead the surgeon to consider arthrodesis or some type of stabilization method. The incidence of fixation associated with decompression is variable in the literature, but this is probably related in part to the variety of decom-pressive procedures that may induce more or less instability. Several studies have shown that only 70% of the patients with aspecific LBP are improved after fusion and even that a few percent are aggravated by this procedure. Whether aspecific LBP is the same pathologic entity as the LBP associated with LSS remains to be demonstrated, but the clinical presentation is quite similar. Moreover, these inconstant results of fusion must be discussed in view of the demonstrated increase of morbidity associated with spinal instrumentation (2) as well as the advent of a series of contraindications for stabilization often arising in the older patients presenting with LSS: poor general health, osteo-porosis, obesity, multilevel hypermobility, and risk factors for infection (diabetes and cortisone therapy) (2,3).

For each patient with spinal stenosis, several questions must be answered when surgical treatment is chosen: What type and extent of decompression? Is some type of fixation needed or not? Is back pain as a symptom an argument for fixation? Finally, we still do not know, when there is no demonstrated major and focal instability or progressive deformity, whether stabilization increases the frequency of favorable outcome and improves the quality of outcome, versus selective decompression alone. Also, it is not clearly demonstrated whether the type of decompression procedure—partial laminotomy sparing the spinous processes and the supraspinous ligament with reinsertion of the
spinous ligament versus laminectomy—has an influence on pre-existing LBP or prevents postoperative instability and LBP (5,7,8).