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

BACKGROUND: The Norwich Patellar Instability (NPI) score is a tool to evaluate the impact of the patellofemoral instability on the joint function. It has not been translated or culturally adapted for the Brazilian population. This study aimed to translate and culturally adapt the NPI score into Brazilian Portuguese and assess its validity for the Brazilian population. DESIGN AND SETTING: Translation, cross-cultural adaptation and validation study conducted at the State Public Servant Institute of São Paulo in Brazil. METHODS: Sixty patients of both sexes (aged 16-40 years), diagnosed with atraumatic patellofemoral instability were evaluated. The translation and cultural adaptation were undertaken by its translation into Brazilian Portuguese, back-translation to English by an independent translator. Face validity was assessed by a committee of experts and 20 patients with patellofemoral instability. Concurrent validity was assessed by comparing the Brazilian Portuguese NPI score to Brazilian Portuguese versions of the Lysholm Knee Score and the Kujala Patellofemoral Disorders Score with 40 patients with patellofemoral instability. The correlation analysis between the three scores was performed using the Pearson correlation coefficient with a significance level of P < 0.05. RESULTS: The Brazilian Portuguese version of the NPI score was moderately correlated with the Lysholm Knee Score (r = -0.56; 95% confidence interval, -0.74, -0.30; P < 0.01) and Kujala Patellofemoral Disorders Score (r = -0.57; 95% CI, -0.75, -0.31; P < 0.01) scores. CONCLUSION: The Brazilian Portuguese version of the NPI score is a validated tool to assess patient-reported patellar instability for the Brazilian population

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

BACKGROUND: The Norwich Patellar Instability (NPI) score is a tool to evaluate the impact of the patellofemoral instability on the joint function. It has not been translated or culturally adapted for the Brazilian population. This study aimed to translate and culturally adapt the NPI score into Brazilian Portuguese and assess its validity for the Brazilian population. DESIGN AND SETTING: Translation, cross-cultural adaptation and validation study conducted at the State Public Servant Institute of São Paulo in Brazil. METHODS: Sixty patients of both sexes (aged 16-40 years), diagnosed with atraumatic patellofemoral instability were evaluated. The translation and cultural adaptation were undertaken by its translation into Brazilian Portuguese, back-translation to English by an independent translator. Face validity was assessed by a committee of experts and 20 patients with patellofemoral instability. Concurrent validity was assessed by comparing the Brazilian Portuguese NPI score to Brazilian Portuguese versions of the Lysholm Knee Score and the Kujala Patellofemoral Disorders Score with 40 patients with patellofemoral instability. The correlation analysis between the three scores was performed using the Pearson correlation coefficient with a significance level of P and#60; 0.05. RESULTS: The Brazilian Portuguese version of the NPI score was moderately correlated with the Lysholm Knee Score (r = -0.56; 95% confidence interval, -0.74, -0.30; P and#60; 0.01) and Kujala Patellofemoral Disorders Score (r = -0.57; 95% CI, -0.75, -0.31; P and#60; 0.01) scores. CONCLUSION: The Brazilian Portuguese version of the NPI score is a validated tool to assess patient-reported patellar instability for the Brazilian population