Abstract
Introduction
Difficulty remains in identification of the sources of low back pain (LBP) due to spinal degenerative disorders. Degenerative intervertebral disc (IVD) may contribute to pain generation. However, the relationship of disc degeneration and occurrence of LBP is still unclear, which makes it difficult to locate a surgical target for a discectomy and predict the clinical outcome. The purpose of the present study was to explore the characteristic changes of a painful disc in MRI and attempt to clarify the underlying role of inflammatory mediators and AF tears in disc degeneration and LBP occurrence.
Materials and Methods
Human disc specimens and MRI from 57 single segment IVD protrusion patients with radiculopathy were collected by discectomy. VAS of low back pain were recorded before and postsurgery for all patients. All patients were grouped according to the LBP occurrence or the disc degeneration Pfirrmann grades. Degenerated disc inflammatory mediators (IL-1β, TNF-α, iNOS, and substance P) expression were compared with immunohistochemical analysis and real-time polymerase chain reaction (RT-PCR) among different groups. The relationship of IVD degeneration severity, incidence of HIZ, and occurrence of LBP was investigated via MRI.
Results
RT-PCR and immunohistochemical analysis showed no significant differences in inflammatory mediators expression between the disc samples with and without LBP. Moderately degenerative IVD according to Pfirrmann grade demonstrated the highest inflammatory mediators expression compared with mildly and severely degenerative IVD. For LBP patients, the postoperative VAS of LBP was significantly decreased. The LBP occurrence in moderately degenerated patients was the highest (70.8%). The HIZ incidence was 75% in moderately degenerated patients, while 61.9% in severely degenerated patients. The patients who demonstrated both moderate disc degeneration and HIZ had 83.3% LBP occurrence, higher than the rest of the patient population.
Conclusion
Moderately degenerative disc with AF tear is a source of LBP. MRI showing moderately degenerative disc with HIZ could be an indication of discectomy and may predict good prognosis.
None declared