Updated project metadata. Circular RNAs (circRNAs) are covalently closed single-stranded RNA molecules produced by reverse splicing of the precursor mRNAs of thousands of gene exons in eukaryotes. Some circRNAs play potentially important roles at the molecular level through different modes of action in physiological and pathological conditions. In recent years, it has been found that differentially expressed circRNAs are present in chondrocyte degeneration in OA and are able to modulate the inflammatory response in chondrocyte degeneration. However, the molecular mechanisms of how circRNAs regulate the inflammatory response during chondrogenic degeneration in OA have not been adequately studied. Are there other circRNAs involved in regulating the inflammatory response during knee OA chondrocyte degeneration and are there other molecular mechanisms by which circRNAs regulate chondrocyte degeneration? These scientific questions deserve relevant studies.