ROUNDS RESPONSE.
Rounds is your vehicle for sharing your orthopaedic skills and experience. Your response to Rounds will be published in a future issue of Body Cast. We invite you to suggest questions for this column. Please address all submissions to: The Editor, Body Cast, 18 Wynford Drive, Suite 715A, North York, Ontario, M3C 3S2.

This Issue's Rounds Question (responses to be published in next issue)
Does dorsal swelling signify an injury or infection in the dorsum of the hand?

In the last issue of Body Cast, Rounds asked:
Describe the difference between anterior and posterior dislocation of the sternoclavicular (SC) joint

The following responses were received:

From Mardy McPolin and Gary James:
Anterior dislocations are not associated with major complications and are easily treated with a clavicle strap. Posterior dislocation of the SC joint may put pressure on the trachea, esophagus, or great vessels, and thus constitutes a true emergency that requires reduction.

From Angela Wentzell:
The anterior dislocation is more common, usually secondary to indirect forces, from medial compression of the clavicle coupled with a posteriorly directed force on the lateral clavicle. This type of injury can occur in sports.

The posterior dislocation of the SC joint is rare. It is caused by both direct and indirect trauma, and the backward displacement of the inner end of the clavicle is extremely hazardous to the mediastinal structures, causing pressure against the trachea and great vessels.

From Blair Matheson:
The difference between anterior and posterior dislocation of a sternoclavicular (SC) joint is:

Firstly, the SC joint is the pivot on which the shoulder girdle moves the trunk. Dislocation of this joint most often results from a fall onto the shoulder.

If the shoulder is pressed and rotated backward, the force directed down the clavicle produces an anterior dislocation of the SC joint, causing severe pain and tenderness over the joint. The anteriorly displaced medial end of the clavicle is generally quite visible. Persistent prominence is usually present but not of functional significance. Closed reductions are usually not successful.

Posterior dislocation of the SC joint is a relatively rare injury, caused by both direct and indirect trauma resulting in the backward displacement of the inner end of the clavicle. This can be of serious consequence, as it can be extremely hazardous to the mediastinal structures, causing pressure against the trachea and great vessels. Closed reductions are generally successful in many cases. If closed reduction fails, then operative intervention is warranted.