T1 weighted angled sagittal image (now labelled):
T2 weighted angled coronal image (now labelled):
There is extensive new bone formation around the acromioclavicular joint (ACJ), seen as low signal on all the images (1). This is due to degenerative change in the ACJ.
This in turn impinges on the supraspinatus tendon, which has ruptured, as evidenced by the discontinuity of the tendon on the coronal images, the retracted muscle belly (2), the fluid extending from the joint into the subacromial bursa (3)
Complete rotator cuff tear, secondary to impingement syndrome.