FEMOROPATELLAR GLIDING MOVEMENT DURING ACTIVE STRETCHING OF THE KNEE - IMAGING WITH MOVEMENT-TRIGGERED MR TOMOGRAPHY

By means of motion-triggered MRT it has been possible for the first time to demonstrate movements in the patello-femoral joint by means of MRT. Patello-femoral movement was studied during active extension of the knee between 30-degrees flexion and complete extension. The knees of 5 normal females and 7 normal males were studied together with 2 women with recurrent lateral patellar luxation. In normal women there was an average 16-degrees (10 to 18-degrees), in men an average of 12-degrees (10 to 14-degrees) of lateralisation of the patella during complete extension of the knee. In 1 patient there was 10-degrees medial displacement of the patella before extension. In 2 knees with recurrent lateral subluxation there was a 20 and 24-degrees displacement of the patella.