In order to study the etiology of the discorders of the patellofemoral joint, 63 patients with knee pain were examined clinically and radiologically.
Analysis of the X-ray pictures of these patients were carried out by measurement of patellar index, sulcus angle and Q-angle. Joint laxity were judged by the method of carter.
In eight patients of recurrent dislocation of the patella, all of their shape of patella were in Wiberg's type 3.
The Q-angle tended to increase in female patients. This angel also increased in patients with patellar dislocation and chondromalacia.
In patients with recurrent dislocation of the patella, joint laxity tended to increase, so range of motion in internal rotation and external rotation of hip was increased.
There are significant correlations between the sulcus angle and the type of patellar shape, that is, in Wiberg's type 3 the sulcus angle is greater than others.
