Question: what is a type 1 acromion?
Answer: Type I acromion is flat (17% incidence); type II (43% incidence) curves downward into the rotator cuff outlet; and type III (40% incidence) is hooked downward into the rotator cuff outlet. Of patients with rotator cuff tears, 70% have type III acromion, 27% have type II, and 3% have type I.