Presentation
Pain and swelling in relation to right SCJ from fall 3 months ago. Prominent right medial clavicle.
Patient Data
There is evidence of a dislocation of the right sternoclavicular joint with a distraction of approximately 20mm. The distance between the superior cortex of the coracoid process and the undersurface of the clavicle where the coraco-clavicular ligaments inserts measures 7mm (normal 11-13mm).
On further inspection of the bilateral sternoclavicular joint (SCJ) radiograph, there was an incidental finding of a previous distal third left clavicular fracture without formed bony union, associated degenerative changes, large osteophytes and bony fragmentation. This was not provided in the clinical history.
Case Discussion
The right acromioclavicular joint in this patient has an increased joint space of approximately 6mm indicating subluxation accompanying the SCJ dislocation. It would be interesting to find out how a 3-month-old SCJ dislocation affected his activities of daily living!
The SCJ is a synovial saddle type joint between the manubrium of the sternum and the proximal end of the clavicle. The range of movement includes antero-posterior and supero-inferior motion and axial rotation. Significant trauma or force (direct or indirect) such as a fall, in this case, can cause disruption to the ligaments supporting the SCJ enabling traumatic dislocation of the joint:
- anterior dislocations which are more common results from an indirect action that rotates the shoulder posteriorly transmitting stress to the SCJ
- posterior dislocations results from a force pushing the shoulder anteriorly or from direct impact to the superior sternal or medial clavicular surfaces
In SCJ dislocations, CT is more accurate in the assessment of the sternoclavicular region and its adjacent structures. Mediastinal structures can be compromised in posterior dislocations.