Author(s): Igarashi A, Kikuchi S, Konno S, Olmarker K
STUDY DESIGN: A prospective study of surgical cases of degenerative lumbar spinal disorders demonstrated inflammatory cytokines in the facet joint tissue. OBJECTIVE: To quantify various inflammatory cytokines released from the facet joint tissue in surgical cases of degenerative lumbar spinal disorders. SUMMARY OF BACKGROUND DATA: In degenerative lumbar spinal disorders, pain is often caused by osteoarthritis of a facet joint. There are inflammatory mediators such as prostaglandins and leukotrienes in facet joint tissue in lumbar spinal degeneration. However, no reports have studied if there are also inflammatory cytokines in the facet joint, which generated arthropathic changes in degenerative lumbar spinal disorder and if pain is caused by chemical factors associated with inflammation such as inflammatory cytokines. METHODS: Forty patients with degenerative lumbar disorders who had undergone operative treatment were included in this study. Fifty-five joint cartilages and 67 synovia were harvested from the lumbar facet joints in responsible intervertebral levels of patients. There were 24 male and 16 female subjects with average ages of 50 and 67 years, respectively, in 11 cases of lumbar disc herniation and 29 cases of lumbar spinal canal stenosis. Using ELISA and CLEIA methods, joint cartilage and synovial tissues were harvested during surgery from the facet joint at the responsible upper levels to measure IL-1beta, TNF-alpha, and IL-6 in individual tissues. RESULTS: IL-1beta was detected in joint cartilage and synovium in both groups and its positive reaction rate was higher in LSCS than in LDH. There was no difference in IL-1beta concentration in cartilage tissue between the two groups. There was TNF-alpha in the synovium of LSCS. IL-6 was high in joint cartilage and synovium in both groups. The concentration was significantly higher in LSCS than in LDH. CONCLUSIONS: There are inflammatory cytokines in facet joint tissue at high levels in degenerative lumbar spinal disorders. Inflammatory cytokines have a higher concentration rate in lumbar spinal canal stenosis than in lumbar disc herniation. This finding suggests that inflammatory cytokines in degenerated facet joints may have some relation to the cause of pain in degenerative lumbar disorders.