Snapping scapula syndrome: three case reports and an analysis of the literature.

The snapping scapula syndrome is an infrequently described source of shoulder discomfort characterized by painful, audible, and/or palpable abnormal scapulothoracic motion. The syndrome may be caused by skeletal or soft-tissue abnormalities that interfere with articulation between the scapula and the rib cage. Often, no obvious source of the snapping can be identified with imaging studies. Three new cases with electrodiagnostic and imaging studies are presented. For the first time a critical analysis and review by diagnoses, gender, age, treatment, and outcome of 89 reported cases is presented. Accurate recognition of the syndrome may lead to prompt and long-term relief of symptoms by conservative or surgical treatment.