The hung up shoulder: anterior subluxation locking in abduction.

The hung up shoulder, or anterior subluxation locking in abduction, is a bizarre clinical picture which is not frequently seen. It is probably due to the fact that, in the subluxed position, the subscapularis muscle becomes an abductor, rather than an internal rotator. External rotation might shift the subscapular muscle fibres towards the proximal aspect of the humeral head, while joint laxity favors subluxation. It is possible that the hung up shoulder is just one aspect of multidirectional shoulder instability, given the tendency to generalised joint laxity, the frequent autoreduction, the positive sulcus sign, and initiation of subluxation by either abduction-external rotation or extension. In this series three out of four patients were treated conservatively and performed well in daily life; however, only the fourth patient had almost unlimited access to sports, thanks to surgical stabilization.