RELIABILITY OF ASSESSING PATELLAR ALIGNMENT - THE A-ANGLE

Anterior knee pain syndrome is a complex problem for clinicians and pa tients. One possible etiological factor that has been identified is ma lalignment of the patella. Recently, a clinical method to assess patel lar malalignment has been proposed-the A angle. However, no reliabilit y of this technique was reported. Therefore, the purpose of this study was to determine intrarater and interrater reliability for the A angl e. Thirty-six subjects participated in this study. Three raters measur ed each knee twice (N = 70). Interclass correlation coefficients (ICC) and standard error of measurements (SEM) were determined for the A an gle and component measurements. Intrarater A-angle values ranged from 11.8 to 23.5-degrees. Intrarater A-angle ICCs were poor (0.20-0.32, SE M = 5.30-7.95-degrees) Interrater A-angle ICC was poor (-0.01, SEM = 7 .82). Results indicated that the A angle as determined in this study w as not reproducible. Therefore, further study is needed before the A a ngle can be used as a reliable assessment tool for patellar position.