acromioplasty

noun

ac·​ro·​mio·​plas·​ty ə-ˌkrō-mē-ō-ˈplas-tē 

plural acromioplasties

: surgical cutting, shaping, and smoothing of the front or lower surface of the acromion to relieve compression of the rotator cuff between the acromion and head of the humerus when the arm is raised overhead

In a procedure called acromioplasty, surgeons shave away some of the bone to make more room for the rotator cuff, in hopes of alleviating pain and preventing tears.

—Robert Langreth, Forbes