Posterior shoulder dislocations and fracture-dislocations are uncommon
injuries that most often occur during seizures or as a result of high-energy
trauma. Despite advances in imaging, they are frequently diagnosed late.
Detection is facilitated by heightened clinical suspicion of the injury in
high-risk individuals together with appropriate radiographic
investigation.
A wide variety of operative techniques, ranging from simple closed
reduction to soft-tissue and bone stabilization procedures to prosthetic
arthroplasty, are available to treat these injuries. Selection of the most
appropriate treatment option is complex and multifactorial. Because of the
rarity of these injuries, evidence-based treatment protocols are difficult to
devise.
Good functional outcomes are associated with early detection and treatment
of isolated posterior dislocations that are associated with a small osseous
defect and are stable following closed reduction. Poor prognostic factors
include late diagnosis, a large anterior defect in the humeral head, deformity
or arthrosis of the humeral head, an associated fracture of the proximal part
of the humerus, and the need for an arthroplasty.