<![CDATA[Background: Standardized outcome instruments are essential for evaluating pain, function, and clinical status in patients with ankle and hindfoot disorders. The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score is widely used internationally, but a formally validated Indonesian-language version is needed for use in Indonesian clinical practice and research. Objective: This study evaluated the validity and reliability of the Indonesian version of the AOFAS Ankle-Hindfoot Score in adults with ankle and hindfoot disorders. Methods: A methodological validation study was conducted in a multicenter clinical setting. Adults with traumatic, postoperative, or degenerative ankle and hindfoot disorders who could understand Indonesian and provide informed consent were included. The AOFAS score was assessed together with the Foot and Ankle Outcome Score (FAOS) and Short Form-36 (SF-36). Internal item validity was examined using Pearson correlation, internal consistency using Cronbach’s alpha, and inter-rater reliability using Cohen’s kappa. Convergent validity was assessed by correlation with FAOS and SF-36. Floor and ceiling effects were also examined. Results: Eighty-seven participants were included in the descriptive analysis. The mean age was 40.0 ± 16.1 years, 58.6% were male, and 44.8% had a university education. The mean AOFAS Ankle-Hindfoot Score was 59.03 ± 19.72. In the 81 participants included in item-level validation and inter-rater analyses, all nine AOFAS items were valid, with item correlations ranging from 0.623 to 0.856 and p < 0.001. Internal consistency was high (Cronbach’s alpha = 0.851). Inter-rater reliability was excellent, with Cohen’s kappa values ranging from 0.911 to 1.000 and a mean kappa of 0.975. Convergent correlations were strong with FAOS (r = 0.850) and SF-36 (r = 0.911), both p < 0.001. No floor or ceiling effect was observed for the total AOFAS score. Conclusion: The Indonesian AOFAS Ankle-Hindfoot Score demonstrated good internal validity, high internal consistency, excellent inter-rater agreement, and strong convergent validity in the study population. It can therefore be considered a useful instrument for assessing ankle and hindfoot function in Indonesian adults, although further studies should evaluate responsiveness and performance in specific non-traumatic populations.]]>
