Validation of the French version of the KOOS-child questionnaire

The Knee Injury Osteoarthritis Outcome Score (KOOS) questionnaire is one of the frequently used outcome scores in pediatric studies. However, a recent study demonstrated that the pediatric population had a limited understanding of some of its questions. Therefore, the KOOS-Child questionnaire was developed specifically for this population. Our team produced a French adaptation based on the English version. The objective of the current study was to validate the French adaptation of the KOOS-Child questionnaire.

After ethic board approval, the questionnaire was translated from English to French by two French speaking orthopedic surgeons. Following consensus, the translated version was retranslated to English by a professional translator. A group of experts compared the original and back translated version and decided on a final adapted questionnaire version. Ninety-nine 8-16 year-old patients were prospectively recruited from our pediatric orthopedic surgery clinic. Twenty-one control participants and 78 patients suffering from knee pain were recruited. The participants were asked to answer the translated French version of the KOOS-Child questionnaire and two validated French pediatric quality of life surveys.

Statistical analysis demonstrated no statistically significant demographic difference between the control population and the patients suffering from a knee pathology. The mean for the five different domains of the KOOS-Child questionnaire showed statistical differences (p < 0.001) between the two groups. Construct validity was demonstrated through testing of previously validated hypothesis of correlation. Internal consistency was also confirmed in injured patients.

In conclusion, the current study results demonstrate good to excellent internal consistency, good construct validity and inconclusive discriminant capacity of the French adaptation of the KOOS-Child questionnaire.

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