Background:

The posterior dislocation of the glenohumeral joint is infrequent, it represents less than 5% of all shoulder dislocations. In the emergency services, it is not detected during the primary examination in 60 to 79% of the cases due to inadequate exploration or radiological misinterpretation.

Case report:

35-year-old male who suffered a fall of his height, hitting the floor with the left shoulder in a position of adduction, flexion and internal rotation. He came immediately, with intense pain and the impossibility for function. On the physical examination: left deltoid with moderate atrophy, glenohumeral joint locked in internal rotation, limited flexion, extension and abduction of 30o, 25o and 30o respectively, without external rotation. Magnetic resonance imaging showed a reverse Hill-Sachs lesion associated with posterior glenoid labrum lesion (Bankart-reverse), which was embedded in the humeral head, causing its blockage, as well as deformity in “coma” of the subscapularis muscle.

Conclusion:

The posterior dislocation of the shoulder is infrequent; it can go unnoticed in the emergency services, causing injuries to the joint surfaces that, depending on their severity, require complex surgery to improve joint function.