Prevalence of radiographic ankle osteoarthritis in different subgroups of patients referred for ankle radiography

Background: Ankle osteoarthritis(OA) has detrimental effects on physical health and has a relatively early disease onset compared to OA in other joints. However, the prevalence of radiographic ankle OA in different subgroups of patients referred for ankle radiography remains unknown. Therefore, we aimed to determine the prevalence of radiographic talocrural, subtalar and talonavicular OA(Kellgren-Lawrence scale ≥2) in a population referred for ankle radiography. Moreover, we aimed to identify differences in prevalence between specific subgroups of patients i.e. Body Mass Index (BMI), sex, age and reason for referral. Methods: A cross-sectional study was conducted at a radiology department serving primary and secondary care. Patients completed a questionnaire before radiography. Features of radiographic ankle OA were assessed for subgroups of patients, including; BMI, sex, age and reason for referral (chronic vs (sub)acute complaints). To examine the difference in (features of) radiographic OA for subgroups, multinomial and logistic regression were used to calculate Odds Ratios (ORs), with adjustment for age, sex and BMI. Results: Data from 893 patients that visited the radiology department across 16 months in 2017 or 2018 were included for analysis. Prevalence of radiographic ankle OA was 9.2%, 0.4% and 7.0%, for the talocrural, subtalar and talonavicular joint, respectively. Obesity was associated with radiographic talonavicular OA (adjusted OR 2.16, 95%CI:1.09; 5.26). Radiographic talocrural and talonavicular OA were both positively associated with male sex [(adjusted OR 4.64, 95%CI:276; 7.81) and (adjusted OR 1.95, 95%CI:1.13; 3.35), respectively]. Conclusion: Radiographic ankle OA was more common in men and obese patients that were referred to radiology.