Translation, cross-cultural adaptation and validation of the Norwich Patellar Instability score for use in Brazilian Portuguese

ABSTRACT BACKGROUND: The Norwich Patellar Instability (NPI) score is a tool for evaluating the impact of patellofemoral instability on joint function. It has not been translated or culturally adapted for the Brazilian population before. OBJECTIVE: This study had the aims of translating and culturally adapting the NPI score for use in Brazilian Portuguese and subsequently assessing its validity for this population. DESIGN AND SETTING: Translation, cross-cultural adaptation and validation study conducted at the State Public Servants’ Institute of São Paulo, Brazil. METHODS: Sixty patie...