French translation and validation of the AKPS questionnaire

Introduction: The Anterior Knee Pain Scale (AKPS) is a questionnaire used to examine the subjective symptoms, such as the functional limitations and the anterior knee pain. First developed in English, this questionnaire has since been translated and validated into several languages. The aims of the study were to translate and cross-culturally adapt the AKPS into French and to evaluate the reliability and validity of this translated version of the questionnaire.

Methods: The translation part was articulated in six stages, according to international guidelines: (i) two initial translations from english to french; (ii) synthesis of the two translations; (iii) backward translations into the original language; (iv) expert committee to compare the backward translations with the original questionnaire (v) pre-final version testing and (VI) expert committee appraisal. To validate the French AKPS questionnaire, we assessed its validity, reliability and floor/ceiling effects. To do this, volunteer patients from Belgium and France, with patellofemoral pain syndrome were asked to answer the french version of the AKPS questionnaire at baseline and after 7 days, as well as the generic SF-36 questionnaire.

Results: The AKPS questionnaire was translated without any major difficulties. A total of 101 subjects aged 34.49 ± 11.38 years on average were included in this study. Among them, 58.4% were women. Results indicated an excellent test-retest reliability (intraclass coefficient correlation of 0.97, 95% CI 0.96 - 0.98), a high internal consistency (Cronbach’s alpha of 0.87), a consistent construct validity (high correlations with the SF-36 questionnaire were found with domains related to physical function (r = 0.80), physical role (r = 0.70), pain (r = 0.64)) and low or moderate correlations with domains related to mental health (r = 0.26), vitality (r = 0.32), social function (r = 0.41)). Moreover, no floor/ceiling has been found.

Conclusion: A valid AKPS french questionnaire is now available and can be used with confidence to better assess the disease burden associated with femoropatellar syndrom. It was successfully cross-culturally adapted into French.