As " type A" cells in the synovium attempt to remove the debris, immune cells like lymphocytes and macrophages are recruited into the synovial membrane, which produces proinflammatory cytokines that ultimately cause inflammation of the synovium as well, called synovitis.

滑膜上的A型细胞努力清除这些碎片的同时，免疫细胞（如淋巴细胞、巨噬细胞）也被募集进入滑膜，产生炎症因子，最终导致滑膜炎。