Acromion Fracture

This 70-year-old man slipped and landed on his left side. He presented to the ED complaining of shoulder pain.
This radiograph shows a fracture of the base of the acromion, arrows on magnified image, with no other fracture or dislocation evident.
Isolated acromion fractures are uncommon; acromion fractures make up less than 10% of all scapular fractures and are usually associated with other fractures or soft tissue injuries around the shoulder such as rotator cuff tendon tears. Although generally treated non-operatively, when there is significant displacement an acromion fracture can cause impingement of the adjacent rotator cuff and may require internal fixation.
Stress fractures of the acromion have also been reported, for example in manual labourers, golfers, and gymnasts.

Reference:
Malavolta EA et al. Stress fracture of the base of the acromion: a case report. BMC Musculoskeletal Disorders 2014;15:302.