Have a look at the images below. Shoulder pain.

So- still think it's calcific tendinitis?


The patient suffered an anterior dislocation previously. See the defect on the inferior glenoid rim on the radiograph above? That's a bony Bankart.


And if you go up to the fragment shown above, it does look suspiciously like a piece from the glenoid defect. It's too well-circumscribed and well demarcated. Also, with such a large calcific fragment, shouldn't there be more swelling of the tendon?


So, knowing what you now know, it's likely the bone fragment from the bony Bankart displaced up into the supraspinatus tendon! Take home message: if it's too sharp, look again. Calcific tendinosis is fluffy.