Shoulder impingement syndrome: radiographic evaluation.

The impingement syndrome is an important source of shoulder pain that occurs when the bony and soft-tissue structures of the superior aspect of the shoulder encroach upon the coracoacromial ligamentous arch during abduction of the arm. Subacromial bursitis, bicipital tendinitis, and rotator cuff disruptions are common sequelae of this abnormality. The presence of bony excrescences arising from the anteroinferior aspect of the acromion and of flattening and sclerosis of the greater tuberosity of the humerus is an important plain radiographic sign of the impingement syndrome. Fluoroscopy, shoulder arthrography, subacromial bursography, and bursotomography are fundamental diagnostic imaging modalities in this disorder.