Patella alta: association with patellofemoral alignment and changes in contact area during weight-bearing.

Ward SR, Terk MR, Powers CM        

This study compared patellofemoral joint alignment and contact area in subjects who had patella alta with subjects who had normal patellar position, to determine the effect of high vertical patellar positions on knee extensor mechanics. Twelve subjects with patella alta and thirteen control subjects had lateral patellar displacement, lateral tilt, and patellofemoral joint contact area were quantified from axial magnetic resonance images of the patellofemoral joint acquired at 0 degrees , 20 degrees , 40 degrees , and 60 degrees of knee flexion with the quadriceps contracted. The results indicate that the vertical position of the patella is an important structural variable that is associated with patellofemoral malalignment and reduced contact area in patients with patella alta.

Journal of Bone and Joint Surgery, 2007, 89(8), 1749-55

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