Friday, September 6, 2013

Dysplasia of the shoulder, x-ray appearance


Glenoid dysplasia is a condition in which the posterior part of the glenoid bone fails to form. This has several ill effects: the load on the posterior soft tissues is increased so that the posterior labrum can fail, the humeral head displaces on the retroverted glenoid, and shoulder arthritis can develop due to abnormal loading of the remaining bone.





The MRI of the shoulder often looks like this, showing the dysplastic glenoid bone with soft tissue - presumed  cartilagenous anlage occupying the area that would normally be the posterior glenoid bone.


In the MRI below, we've labeled the bone with the white arrow and the cartilagenous anlage with the red arrow. The blue arrows point to osteophytes on the anterior and posterior humerus, indicating that degenerative arthritis has begun.



As we've emphasized before (see here), two plain x-rays are necessary and sufficient to make most diagnoses of shoulder arthritis. Below is an anteroposterior (AP) and an axillary view typical of shoulders with dysplasia. The upper view, the AP shows the under development of the inferior aspect of the glenoid.


The standardized axillary view reveals much more of the pathology: glenoid is under developed posteriorly resulting in retroversion and posterior translation of the humeral head on the glenoid.



Here are a few more images








As one might expect, surgical reconstruction of the dysplastic glenoid is difficult because of the substantial posterior bone deficiency.

Other posts on glenoid dysplasia are shown below:
Glenoid dysplasia 1
Glenoid dysplasia 2
Glenoid dysplasia 3
Glenoid dysplasia 4
Arthroplasty for dysplasia

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.

Follow on twitter: https://twitter.com/shoulderarth
Follow on facebook: click on this link
Follow on facebook: https://www.facebook.com/frederick.matsen
Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link)