Liu K, Cai F, Liu Y, et al. - The present study was conducted to evaluate the risk factors of ankle osteoarthritis in the treatment of critical bone defects using the Ilizarov technique. Researchers enrolled a total of 236 patients [199 males and 37 females with a mean age of 47 years (range 28–59 years)] who had undergone bone transport surgery for tibias using the Ilizarov external circular fixator from 2008 to 2018. Researchers estimated the cumulative incidence of ankle OA diagnoses in patients after the Ilizarov technique treatment and stratified by risk factors from preoperative and postoperative management. There were 199 males and 37 females with a mean age of 47 years (range 28–59 years). For critical bone defects, Ilizarov external circular fixator was found to be a safe and effective method of treatment. The data illustrated that double-level bone transport, EFI > 50days/cm, age > 45years, osteoporosis, BMI > 25 are the top five relevant risk factors of ankle OA. Among patients having three or more risk factors, the probability of developing ankle OA is 50–70 %.