Objectives: The measurement of the interleukin-6 level in the synovial fluid of the diseased joints before, during, and after arthrocentesis to evaluate its validity as biochemical monitor.

Materials and methods: Sixteen patients complaining of pain, clicking, and limitation in mouth opening were recruited. Pain, maximal mouth opening, and clicking was recorded. Radiographs and magnetic resonance imaging (MRI) were also performed. Synovial fluid aspirates were obtained prior to arthrocentesis and after infusion of 50, 150, and 300 ml into the joint and immunoenzymometric assay was used to measure its levels. The patients underwent arthrocentesis. The clinical criteria were recorded pretreatment and 1 day post-treatment then at 1, 3, and 6 months post-treatment. The clinical parameters and the interleukin-6 levels were analyzed statistically using one-way ANOVA test.

Results: The cases presented with 25 affected joints. The pain scores decreased significantly and the maximum mouth opening increased significantly also. The interleukin-6 levels showed a decrease after infusion of 50, 150, and 300 ml but without statistical significance.

Conclusion: It was concluded that arthrocentesis proved clinical efficacy. The interleukin-6 was present in the affected joints but was not proved as a monitoring biochemical marker and arthrocenteseis was not efficient to wash it out.