[Etiology of dislocation of the patella (author's transl)].

Using a new method for measuring the distal femoral torsion (Janssen a. Prüssner 1977) it is possible to determine the encreased medial torsion of the distal femur in most of the patients with dislocation of the patella. A group of patients with dislocated knee-cap was studied for this purpose. The characteristic clinical and x-ray features are listed and weighted according to their value. They throw a new light on the pathogenesis and pathomechanics of patellar luxation, and point to the need to reclassify the different types of luxations according to etiological aspects.