Posterior shoulder dislocation

Case contributed by Andrew Murphy


Suspected shoulder dislocation, history of the same.

Patient Data

Age: 30 years
Gender: Male

Inital imaging

Appearances suspicious for a posterior humeral head dislocation, reversed Hill-Sachs and bony Bankart lesion. Further imaging maybe required to confirm a dislocation.


Additional views undertaken

The humeral head does not appear to articulate with the glenoid fossa in keeping with posterior dislocation suspected on earlier imaging.

Pen artefact is noted in the superior aspect of the image, which the radiographer confirmed was used for orientation.

Case Discussion

Posterior dislocations are rare and occur in 2 to 4% of shoulder dislocations; the humeral head is displaced posteriorly due to axial loading of the adducted, internally rotated arm. Often this injury will happen during violent muscular contractions, electric shock, or convulsive seizures. 86% of posterior dislocations will have impacted fractures of the anteromedial portion of the humeral head, otherwise known as a reverse Hill-Sachs lesion 1.

Unlike anterior dislocation which are usually easily identified on an AP projection, posterior shoulder dislocations can be difficult to identify without further views. In this particular case, a Garth's and an axial projection were performed.

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Case information

rID: 53737
Published: 3rd Jun 2017
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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