BackgroundThis study aimed to investigate the prevalence of radiographic ankle osteoarthritis (AOA) in Japan and identify its risk factors. MethodsThe analysis included data from the population-based cohort study, radiographs of the knees and ankles, ultrasonography of the ankle to examine chronic ankle instability (CAI), and questionnaires on ankle pain, job history, height, and body weight. A total of 597 individuals aged > 50 years were included in the study. The risk factors for AOA were calculated using multivariate logistic regression analysis. ResultsThe study revealed a 13.9% prevalence of radiographic AOA among the participants, with 1.2% reporting painful AOA. Female sex, aging, history of ankle fractures, and CAI were identified as the risk factors associated with AOA. ConclusionsThis cross-sectional study highlights the significant prevalence of radiographic AOA in a rural Japanese population, emphasizing the importance of considering ankle fractures and CAI as potential risk factors for AOA development. Levels of evidenceLevel II, prospective cohort study