Rotator Cuff

Muscle Origin on scapula Attachment on humerus Function
Supraspinatus muscle supraspinous fossa greater tubercle abducts the arm
Infraspinatus muscle infraspinous fossa greater tubercle laterally rotates the arm
Teres minor muscle lateral border greater tubercle laterally rotates the arm
Subscapularis muscle subscapular fossa lesser tubercle medially rotates the humerus

Bone Island

A bone island, also known as an enostosis, is a focus of compact bone located in cancellous bone. This is a benign entity that is usually found incidentally on imaging studies; however, the bone island may mimic a more sinister process, such as an osteoblastic metastasis.
In CT: a round nodule without extension outside the cancellous bone and does not cause bony destruction