I read the recent article with great interest entitled “Patient-reported joint status and quality of life in sports-related ankle disorders and osteoarthritis” by Kolar et al. The authors of the study aimed to compare the patient-reported outcome measurements for the assessment of the health-related quality of life, activity level, and pain severity of the patients with several common ankle disorders. Pre-operative evaluation results for seven different pathological conditions were evaluated with a different statistical analysis method. While I believe the publication provides essential contribution to the literature, there are some methodological concerns that I would like to address which may affect the results of the study [1].

Firstly, Kolar et al. used the Tegner activity scale (TAS) to evaluate the patients’ activity level. TAS, as stated by the authors, is developed and generally used in knee injuries. Psychometric properties for knee patients have been revealed and proven to be valid-reliable. The authors argued that in reference 13, TAS was used to demonstrate the level of activity associated with the other joints. Looking at the article of reference 13, they used TAS for validation in the new scoring system that Halasi and colleagues developed in 2004 to evaluate the activity level of individuals with ankle instability. However, when the literature is reviewed, it is seen that TAS has not been validated for the foot or ankle and its psychometric properties have not been studied in any way. In this respect, it should be stated that TAS may not provide precise measurement in the ankle pathologies [2].

Secondly, it was stated that the Foot and Ankle Outcome Score (FAOS) and TAS values obtained in the evaluation results were compared with the average normative values of the general population by considering the cutoff values specified in reference numbers 10 and 15. However, the average TAS values calculated for different age groups in reference number 15 are for the knees of healthy individuals. For this reason, the comparison made with the normative values in this study could lead to a misleading statistical analysis [3].

Last but not least, in the Method section, it was not specified which language translation version of FAOS was used. Looking at the Clinical Trials record, the study was conducted in Slovenia. It has been emphasized that while using such PROs, the items must not only be translated well linguistically but also must be adapted culturally to maintain the content validity of the instrument with the permission [4]. This is an important procedure for the level of evidence of the study. Therefore, it is also important to state whether the Slovenian version is used or not. I would welcome the comments of the authors to address these issues, which will further provide additional information about their study.