Correlation of Tumor Necrosis Factor-α Expression with Pain Level in Degenerative Lumbar Canal Stenosis Patients

Abstract

Introduction: Pain in degenerative lumbar canal stenosis is caused by osteoarthritis of a facet joint and intervertebral disc degeneration. Some inflammatory mediators such as tumor necrosis factor (TNF)-α are present in degenerative lumbar canal stenosis. This study aimed to evaluate the correlation of pain and functional pre-operative scores with the expression of TNF-α in nucleus pulposus, annulus fibrosus, and facet joint. Methods: Patients diagnosed with degenerative lumbar canal stenosis and planned for surgical treatment were included in this study. Patients with history of fracture, neoplasm, and/or infection of the spine were excluded. Tissue samples were collected from the nucleus pulposus, annulus fibrosus, facet joint, flavum ligament and paraspinal muscles of the spine during the surgery. TNF-α expression was examined semi-quantitively and correlated with the axial and radicular pain that were measured using Visual Analog Score (VAS) score. The result was then statistically analyzed. Results: The expression of TNF-α in the paraspinal muscle (6.30±14.20) was significantly higher compared to other locations. TNF-α expression in the facet joint group was significantly correlated with the intensity of low back pain measured by VAS score (r=0.893, p < 0.001), and pre-operative functional outcome based on Oswestry Disability Index (ODI) (r=0.948, p < 0.001). Conclusion: TNF-α expression, especially in the facet joint, is significantly associated with the pain intensity and pre-operative ODI that allow pain reduction with less invasive treatment in lumbar canal stenosis patients.