Influence of macrophage infiltration of herniated lumbar disc tissue on outcome after lumbar disc surgery.
STUDY DESIGN: An immunohistochemical examination of the presence of inflammatory cells in routinely processed resection specimens of the lumbar disc, and a comparison of the histologic results with clinical data collected prospectively before and after surgery. OBJECTIVES: To assess the influence of inflammatory reactions in herniated lumbar disc specimens on the outcome after lumbar disc surgery. SUMMARY OF BACKGROUND DATA: Histologic and biochemical studies on herniated lumbar disc tissue led to the notion of inflammation-induced sciatic pain. At this writing, no investigations have sought to discover how outcome after lumbar disc surgery is influenced by histologically described inflammation. METHODS: Disc specimens from 79 patients who underwent surgery for lumbar disc herniation were studied immunohistologically with regard to the presence of inflammatory reactions. Of these, 92% were followed up approximately 7 months after surgery. The histologic results were compared with the outcome at follow-up evaluation. RESULTS: A statistically significant correlation was found between the histologically proven inflammation and the outcome, as shown by the pain grading scale. CONCLUSIONS: The results from this study seem to support the theory of a foreign body reaction to the herniated material. This reaction may result in inflammation-induced sciatic pain.