[Posterior locked shoulder fracture-dislocation: anatomical resconstruction of reverser Hill-Sachs lession].

The posterior instability of the shoulder only represents 4% of the shoulder instabilities. For the diagnosis, the antero-posterior, transtoracic and axilar radiographic projections are recommended. The inverted Hill-Sachs lesion is a fracture caused by compression of the antero-medial part of the humeral head during the posterior dislocation. Its treatment results, at least, controverted. Choosing the treatment of these lesions one of the main factors is the size of the defect in the humeral head. When it is smaller than 20%, the simple reduction usually is enough. Between 20-40%, we can opt for a transposition of the subescapular insertion to the bony defect (technique of MacLaughlin) or the anatomical reconstruction of the head by means of the fixation of an allograft. The transposition of the subescapular´s tendon carries a reduction of the internal rotation by medializing its insertion, for this reason, we opted for the anatomical reconstruction with allograft of femoral head that reestablishes the muscular balance. The shoulder artroplasty is elective when bony defects are bigger (>40-50 % of the articulation surface). We present the case of a 32 year-old patient, with the antecedent of convulsive crisis. Clinically he suffered intense pain with functional impotence and elastic limitation for the external rotation in left shoulder. The radiographic studies evidenced an instable posterior fracture-dislocation with inverted Hill-Sachs lesion associated that involved the 30% of the articular surface. The patient was surgically treated, opting for a reconstructive technique for humeral head. After six months, the range of motion is almost symmetrical with regard to the healthy shoulder, without any clinic of instability.