THE INFLAMMATORY PROPERTIES OF CONTAINED AND NONCONTAINED LUMBAR DISCHERNIATION

Study Design. The inflammatory properties of nucleus pulposus were ass essed in biopsy samples from patients who underwent surgery for lumbar disc herniation. Objectives. To investigate the inflammatory properti es of the different types of disc herniation. Background Data. High le vels of phospholipase A(2) previously have been demonstrated in a smal l number of patients undergoing lumbar disc surgery. Phospholipase A(2 ) is the enzyme responsible for the liberation of arachidonic acid fro m cell membranes at the site of inflammation and is considered to be t he limiting agent in the production of prostaglandins and leukotrienes , which are powerful mediators of inflammation. Cytokines are among th e many agonists inducing phospholipase A(2) activation. Several report s previously have demonstrated the difference in clinical appearance o f different types of lumbar disc herniation. Methods. Thirty-seven pat ients undergoing surgery for lumbar disc herniation were investigated. During surgery the disc pathology of each patient was classified into one of three groups: bulging disc, contained herniation, and nonconta ined disc herniation. Also during surgery, biopsy samples were taken f rom the nucleus, immediately frozen in liquid nitrogen, and subsequent ly stored at -70 C until analyzed. Results. No traces of interleukin-6 or tumor necrosis factor alpha were found in the biopsy samples. Ther e was a significant difference in the levels of leukotriene B-4 and th romboxane B-2 in contained versus noncontained disc herniation, and th e highest concentration was found in the noncontained disc herniation group. Conclusion. The results support the theory that inflammatory me chanisms are involved in sciatica because of lumbar disc herniation an d indicate that the different types of disc herniation have different inflammatory properties.