Introduction. Among patients with ankle osteoarthritis (OA) a post-traumatic origin is much more frequent than among those with knee or hip OA. However, long-term studies evaluating risk factors for the development of OA after ankle fractures are lacking. Methods. Retrospective cohort study including consecutive patients operated at our institution between 1/1988 and 12/1997 for malleolar fractures treated with open-reduction and internal fixation (ORIF). Ankle OA was independently assessed by two reviewers on standardized radiographs using the Kellgren and Lawrence (K&L) scale. Multivariate logistic regression analysis was performed to determine predictors for OA. Results. 374 patients (56% men) underwent ankle surgery during the study period. 9% had a Weber A, 58% a Weber B and 33% a Weber C fracture. Mean age at operation was 42.9 years. 12–22 years after surgery, 47 patients had died, 126 were lost to follow-up, and 99 did not respond or refused to participate. 102 patients were available at follow-up (similar age, gender, BMI and type of fracture than those not seen). Mean follow up was 17.3 years. Advanced OA (K&L 3–4) was present in 37 patients (36.3%). Significant risk factors for advanced OA were: fracture type (Weber C 53% vs. Weber B 31% vs. Weber A 0%, p = 0.006), presence of
