An acromioplasty involves shaving of the undersurface of the acromion. The acromion is a projection of bone extending from the shoulder blade out over the top of the shoulder joint and provides attachment for muscles around the shoulder including the trapezius and deltoid muscles.
An acromioplasty is typically performed for patients where their rotator cuff is pinching on the under surface of the acromion and the coraco-acromial ligament. Key hole surgery is used to shave the under surface of the acromion to provide greater room for the rotator cuff tendons to fit under the acromion.
If enough room can be created then the rotator cuff tendons may not pinch on the under surface of the acromion and the pain of impingement can be completely relieved.