Case

A 22yo is injured while ice climbing and landing on the point of an ice pick. The pick penetrated the posterior aspect of their shoulder. The injury caused a small amount of bleeding that was managed at the local hospital. It is now 24 hours later and the patient is able to abduct their arm ~10-15 degrees, but is unable to abduct any further. They are able to flex and extend as well as shrug their shoulders.

Question 3/3 - Given the case history, deltoid dysfunction and probably axillary nerve injury, at what location on the shoulder did the ice pick injury occur?

Click on your selected option(s) below  (correct = 1, over-thinking = 2+)

Case Complete

Incorrect. While the brachial plexus is deep to Erb's point on the neck, supraclavicular is on the anterior side of the neck and the patient history indicates the injury occurred on the posterior side of hte shoulder. 

Incorrect. The triangular interval is of limited importance, it is somewhat distal and only has relevance as deep to the interval would be the radial nerve as it passes to the posterior arm.

Incorrect. The triangular space is on the shoulder and has no structures of major significance (one small artery that we are uninterested in).

Correct!  The quadrangular space allows passage of the axillary nerve and posterior circumflex humeral artery. It is important as injury or swelling here can affect the axillary nerve (as in this patient's case).

Inflammation of the area can cause 'quadrangular space syndrome' where there is numbness and deltoid weakness.

Incorrect. The area superior to the spine of the scapula ('supraspinus') houses the supraspinatus muscle, which is functional in this patient. 

Incorrect. The area inferior to the spine of the scapula ('infraspinus') houses the infraspinatus muscle ,which is functional in this patient.