Salsich GB, Perman WH
The objective of this study was to test the hypothesis that patellar alignment and tibiofemoral rotation alignment explain unique portions of variance in patellofemoral joint contact area in individuals with patellofemoral pain (PFP) and in pain-free control subjects. Twenty-one subjects with PFP and 21 pain-free subjects participated. Subjects underwent magnetic resonance imaging with the knee in full extension and the quadriceps contracted. Measures of patellofemoral joint contact area, lateral patellar displacement, patellar tilt angle, tibiofemoral rotation angle, and patellar width were obtained. In the PFP group, patellar width and tibiofemoral rotation angle explained 46% of the variance in contact area. In pain-free subjects, patellar width was the only predictor of contact area, explaining 31% of its variance. The authors conclude that addressing factors that control tibiofemoral rotation may be indicated to increase contact area and reduce pain in individuals with PFP.
Journal of Orthopedic and Sports Physical Therapy, 2007, 37(9), 521-8