Luxatio erecta of the humerus: the spectrum of injury of inferior shoulder dislocation and analysis of injury mechanisms

Erecta dislocation/inferior dislocation of the shoulder is considered an uncommon injury and the present knowledge stems from case reports or compilation of cases. We believe that there are reasons to believe that the injury is much more prevalent than previously stated. In this review, we discuss the mechanism of injury and based on the number of patients with unusual injury patterns at our hospitals and in the literature, the anatomical features of different variants of inferior dislocation are described. Only a few patients present with their arm still locked in abduction, and most patients with initial inferior dislocation are diagnosed with other types of dislocation or injury. Irreducible dislocation, with tissue blocking the glenoid appears to be a consequence typical of an initial inferior dislocation. Nerve and vascular injuries are overrepresented, as are humeral avulsion glenohumeral ligaments-injuries. The description of shoulder dislocations should ideally include the dislocation path and not only the final position of the humeral head.