[The tangential X-ray investigation of normal patellofemoral joint].

From May 1990 to June 1991, we studied 80 asymptomatic volunteers aged from 18 to 40 years by using axial roentgenograms of the patellofemoral joint, which were taken with Laurin technique, but knee in 30 degree of flexion. Six parameters obtained through radiographic measurements included sulcus angle, congruence angle, lateral patella displacement, patellofemoral index, lateral patellofemoral angle and tilting angle of patella. Radiographic measurements of normal patellofemoral joint are helpful in the diagnosis of patellofemoral joint disease, and provide objective anatomical evidences for surgical treatment. Among the various parameters, congruence angle and lateral patellofemoral angle are more important.