Validity of the Turkish version of the Kujala patellofemoral score in patellofemoral pain syndrome

Objectives: Patellofemoral pain syndrome is one of the most common knee problems, with major effects on quality of life and function. The Kujala patellofemoral score is a functional evaluation instrument to evaluate knee problems related to the patellofemoral system. The aim of this study was to evaluate the validity of the Turkish version of the Kujala patellofemoral score in patients with patellofemoral pain syndrome. Methods: After obtaining permission from Kujala et al., the Kujala patellofemoral score was translated into Turkish. The translated version was administered to 40 patients (32 women, 8 men; mean age 33 +/- 12 years; range 17 to 54 years) twice at a two-week interval to test internal consistency and test-retest reliability of the scale. All the patients had patellofemoral pain syndrome and did not receive any treatment before administration of the scale. Cronbach's alpha coefficient was used to assess internal consistency and Spearman's correlation analysis was used to assess test-retest reliability. Results: Cronbach's alpha calculated for internal consistency of the Kujala patellofemoral score was 0.84. Correlation coefficients of the items to estimate test-retest reliability ranged from 0.613 (p=0.004) to 1.000 (p=0.000), with the mean correlation coefficient of 0.944 (p=0.000). Conclusion: There has been no functional assessment scale validated for Turkish patients with patellofemoral pain syndrome. Internal consistency of the Turkish version of the Kujala patellofemoral score showed good reliability and test-retest results showed high reliability, suggesting that it is an appropriate functional instrument for Turkish patients with patellofemoral pain syndrome.