SET T0043 -
Urgent Care Centre -
Mixed cases

Findings:

Posterior gleno-humeral dislocation.

No evidence of a fracture.

Note (1):

There is loss of congruity at the gleno-humeral joint. This is best shown on the apical oblique view, ie the image on the right. The glenoid cavity and the the head of the humerus are not in alignment.

Note (2):

This abnormality - when present - will be evident on the standard two views of a painful or injured shoulder. Nevertheless, it is often not recognised by the first reader of the radiographs. There are two main reasons why the dislocation is frequently not recognised: (a) failure to consider that a posterior dislocation is a clinical possibility; (b) failure to understand the normal and abnormal anatomy on the two radiographs provided by the radiographer.

Note (3):

The two commonest causes of a posterior dislocation are an epileptic fit or an electric shock. In this case the patient is likely to have fitted whilst sleeping.

Note (4):

Different Emergency Departments will vary in their choice of the 2nd view. Obviously, an AP frontal view will always be provided.

The 2nd view provided here is an apical oblique view of the shoulder.

This particular radiographic projection is a 5 star view. It will show a posterior dislocation brilliantly; also, it is very good at revealing fractures (when present) of the head of the humerus or of the glenoid labrum.

Unfamiliar with the apical oblique view??

See : Accident & Emergency Radiology : A Survival Guide (3rd edition) : Pages 76 & 79

Dislocation at the carpo-metacarpal joint of the thumb. No fracture.

Note the complete loss of alignment between the base of the thumb metacarpal and the trapezium bone.

Normal distal radius and ulna.

There is a scaphoid fracture. The fracture is hairline and through the waist of the scaphoid.

Comment: 

 When assessing any patient with wrist pain - following trauma - we must always assess for the presence of any anatomical snuff box tenderness.

When tenderness is present in the region of the snuff box, the radiographer will provide 4 images of the wrist rather than the standard two views.

The scaphoid bone image/images always need very careful assessment. Many scaphoid fractures are hairline.

See the College of Emergency Medicine Guideline for the Management of Suspected Scaphoid Fracture in the Emergency Department.

http://secure.rcem.ac.uk/code/document.asp?ID=7431

Oblique fracture of the distal fibula.

The AP radiograph appears entirely normal.

The fracture can only be seen on the lateral view; this is a fairly common occurence with this type of fibula fracture.

Why is the fracture not shown on the AP radiograph? The fracture through the fibula is oblique and thus the X-ray beam passes through a very minimal break (ie depth of fracture) in the bone - at all levels - on the AP radiograph.