Low Back Pain, Lumbar Spinal Stenosis

Make the Diagnosis: Low Back Pain, Lumbar Spinal Stenosis

Prior Probability

While low back pain seems ubiquitous, in adults ≥55 years old the radiologists’ qualitative impression of radiographic lumbar spinal stenosis is also common with estimated 21%-30% prevalence for moderate stenosis and 6%-7% with severe stenosis.¹ However, the clinical syndrome of lumbar spinal stenosis requires both the presence of characteristic symptoms and signs, along with radiographic or anatomic confirmation of narrowing or stenosis of the spinal canal. The prevalence of the clinical syndrome of lumbar spinal stenosis estimated from 2 separate studies was reported to be 12% of older men in the general community² and 21% of older adults in a retirement community.³

Population in Whom Lumbar Spinal Stenosis Should Be Considered

The clinical syndrome of lumbar spinal stenosis should be considered in older patients with back pain who also have pain in the buttocks or legs. Neurogenic claudication is pain or discomfort with walking or prolonged standing that radiates beyond the low back area and into 1 or both buttocks, thighs, legs, or feet. In addition to this pain pattern, a provocative worsening with lumbar extension and improvement with sitting or lumbar flexion is typical.³  Radicular pain may occur with lumbar spinal stenosis, and this is characterized by a distribution into 1 or more dermatomes that is present irrespective of activity.

Assessing the Likelihood of Lumbar Spinal Stenosis

The patient's symptoms are most useful when determining the likelihood of lumbar spinal stenosis and symptoms have narrower confidence intervals than the findings from physical examination (Table 83-1). The absence of neurogenic claudication was the most useful single finding for decreasing the likelihood of the clinical syndrome of lumbar spinal stenosis. However, a combination of findings works even better for identifying patients unlikely to have the clinical syndrome (Konno score,⁴ Table 83-2).