Surgical Treatment of Humeral Head Defect in Shoulder Posterior Instability

Abstract

Posterior instability of glenohumeral joint represents 3% of all shoulder dislocations [1]. Posterior instability can be classified according to the grade, direction, mechanism of displacement and timing of the trauma (acute, chronic, locked or non-locked and recurrent posterior subluxation). McLaughlin described two main types of posterior instability: chronic posterior displacement and recurrent posterior subluxation [2]. Posterior dislocation is to be considered chronic after 3 weeks from the traumatic event; the recurrent form can be caused by a single traumatic posterior displacement, but usually less than 10% of such dislocations have a recurrence. Possible causes of recurrence include microtrauma due to repeated shoulder movements in a risky position, like in some athletes (rugby, bench press, swimming, etc.) or professionals. An enhanced laxity, generalized or localized to the shoulder girdle, has to be investigated in all cases of posterior shoulder dislocations.