Purpose: To translate the patellofemoral disorder questionnaire "Kujala Score" into Spanish and to adapt it for Spanish culture .
Methods: International recommendations were followed to translate the "Kujala Score" into Spanish together with a cultural adaptation and validation. We analysed the following parameters: internal consistency, agreement construct validity, test-retest reliability, ceiling and floor effects, and responsiveness. The reproducibility and responsiveness were tested in 72 patients with patellofemoral pain syndrome in a test-retest design with follow-up testing at 7 days. The "Kujala Score" and the VISA-P were administered to 98 patients and 30 patients, respectively, who completed the "Kujala Score" and VISA-P after physiotherapy treatment, which consisted of rest, ice, proprioceptive exercise and manual therapy.
Results: The Spanish "Kujala Score" had high internal consistency (Cronbach α = 0.8; if an item was deleted, Cronbach α = 0.77-0.80), excellent reliability and agreement (interclass correlation coefficient = 0.99), and good construct validity that was significantly correlated with the outcome of the Spanish VISA-P (Spearman rho = 0.7; P < 0.001). No ceiling or floor effects was detected for the Spanish "Kujala Score" or the responsiveness of the participants based on 40 patients receiving physical therapy, rest, ice and proprioceptive exercises for 1 month, demonstrating that it is a good determinant of changes in the symptomatology of patients with knee pain.
Conclusions: The Spanish adaptation of the patellofemoral disorder questionnaire "Kujala Score" proved to be valid and sensitive to clinical changes and to be a reliable instrument to assess the severity of pain and disability in patients with patellofemoral disorders. This questionnaire will be useful in clinical practice and research as an appropriate tool to evaluate and record the symptomatology of patients with patellofemoral pain syndrome among Spanish population.
Level of evidence: Diagnostic study, Level I.
Keywords: Kujala score; Patellofemoral pain syndrome; Questionnaire; Translation.