Ultrasonographic Diagnosis of Non-displaced Avulsion Fracture of the Acromion: A Case Report

Avulsion fracture of the acromion is rare. It is difficult to diagnosis because there is little displacement and it occurs even without direct trauma. We experienced a case without direct trauma that was diagnosed with ultrasonography. A 55-year-old male patient visited our outpatient clinic with shoulder pain resulting from a significant stress at the trapezius muscle during lifting of a steel reinforcement. Simple radiography revealed a calcific deposit over the acromion rather than a fracture. Avulsion fracture was identified with ultrasonography. This is the first report demonstrating that ultrasonography has an advantage over radiographs in the diagnosis of an avulsion fracture of the acromion of the scapula.