Patellofemoral relationships in normal subjects determined by computed tomography.

The normal relationships of the patellofemoral joint with the knee in extension were measured with computed tomography (CT) in 43 normal adults. The upper and lower halves of the joint were examined. The range in measurement of the sulcus angle was 115 degrees - 172 degrees, of the congruence angle 43 degrees - 27 degrees, and of the lateral patellofemoral angle 26 degrees - 11 degrees. No significant differences were found between men and women or between the right and left sides. There were some differences between the measurements of the upper and lower halves of the joint. These data may serve as a basis for the evaluation of patients with abnormalities of the patellofemoral joint.