RESUMEN
BACKGROUND: Lumbar spinal stenosis is a common degenerative disease that causes low back and lower-extremity pain that increases with age. The treatment of lumbar spinal stenosis is either conservative or surgical. ESI is a commonly performed conservative treatment, but evidence of its effectiveness in lumbar spinal stenosis is limited. CASE SERIES: We encountered the three patients with back pain and claudication due to lumbar spinal stenosis, which could not be controlled by conservative therapy including ESIs. Trimacinolone acetonide was injected into the patients' ligamentum flavum. All patients experienced dramatic improvement in their symptoms. CONCLUSIONS: Trimacinolone acetonide injection into the ligamentum flavum may be effective for lumbar spinal stenosis that does not improve with ESIs.