CORRELATION OF INFLAMMATORY CYTOKINES WITH ARTHROSCOPIC FINDINGS IN PATIENTS WITH TEMPOROMANDIBULAR-JOINT INTERNAL DERANGEMENTS

Purpose: The goal of this study was to evaluate the presence of the in flammatory cytokines interleukin-1 beta (IL-1 beta), interleukin-6 (IL -6), and tumor necrosis factor-alpha (TNF-alpha) within the superior t emperomandibular joint (TMJ) space in patients with internal derangeme nts and to compare these values with the pathologic findings seen arth roscopically. Patients and Methods: Thirty patients with symptomatic T MJ dysfunction and clinical and imaging evidence of internal derangeme nts of the TMJ were evaluated. Before entering the superior joint spac e with the arthroscope, 2 mL sterile saline was injected and, after 30 seconds of equilibration, was aspirated for analysis. The surgeon the n performed diagnostic arthroscopy. The degree of synovitis, degenerat ion, percent condylar roofing, and any pathologic changes, such as per forations, were recorded. The level of total protein in each sample wa s ascertained, as well as the levels of IL-1 beta, IL-6, and TNF-alpha . Results: Of 30 samples tested, three were discarded because of failu re to gain access into the superior joint space. Of the 27 remaining s amples, IL-6 showed the closest correlation with the level of acute sy novitis demonstrated arthroscopically. Two of the higher IL-6 levels ( 167 and 324 pg/mu g protein) were seen with patients with a significan t disc perforation. In patients with a high degree of vascularity, IL- 6 was found to be between 0 to 581 pg/mu g protein with an average of 80 pg/mu g protein and a median value of 43 pg/mg. These values signif icantly correlated with the degree of vascularity (P less than or equa l to .02). This is in comparison with the 10 remaining patients, who s howed significantly fewer vascular changes arthroscopically. In these patients, the range of IL-6 was 0 to 35 pg/mu g protein, with an avera ge of 19 pg/mu g protein and a median value of 14.5 pg/mu g. These val ues significantly correlated with the smaller degree of vascularity (P less than or equal to .02). In seven patients, the role of nonsteroid al antiinflammatory drug (NSAID) use resulted in decreased levels of I L-6, which has been noted in previous studies. In patients with higher rated redundancy of the synovial tissue, the average IL-6 level was 9 2 pg/mu g protein, whereas the median value was 44 pg/mu g protein. In patients with little or no redundant synovial tissue, an average IL-6 level of 22 pg/mu g protein was present. The median value in these sa me joints was 15 pg/mu g protein. These IL-6 values significantly corr elated with the degree of redundancy (P less than or equal to .03). Th e degree of degenerative change (chondromalacia, fibrilation), disc di splacement (roofing), and the presence or absence of adhesions did not significantly affect the levels of IL-6 within the patients studied. The presence of IL-1 beta and TNF-alpha was not found to correlate wit h the arthroscopic findings in the superior joint space. Conclusions: The presence of IL-6 correlated with the degree of acute synovitis. IL -1 beta and TNF-alpha were not found in significant levels within the superior joint space. These findings correlated with those reported by other investigators. The production of IL-6 by synovial cells and its role in TMJ disease warrants further investigation.