[The value of arthroscopy for diagnosis of instability of the shoulder joint].

As a glenohumeral instability is defined each case of transient recurrent and permanent decentration of the joint. We propose to differentiate primary and secondary glenohumeral instabilities. Arthroscopical diagnostic is helpful to classify the luxation and subluxation and for verify transient instabilities. In cases clinically snapping phenomena were noticed, arthroscopic findings were documented. A relation between those phenomena and arthroscopic findings is discussed.