Rheumatoid arthritis: skeletal manifestations observed on portable chest roentgenograms.

This report describes the thoracic skeletal radiographic findings of rheumatoid arthritis, observed on portable chest examinations of 21 patients. Their pathophysiology is reviewed and additional examples of a recently described finding are illustrated: erosion of the medial surface of the proximal humerus with subsequent pathologic fracture, associated with superior and medial migration of the humeral head. It has been proposed that erosion of the medial aspect of the proximal humerus is due to impingement wear, and that pathologic fracture results from the fulcrum effect of the inferior lip of the glenoid on the humerus. Rheumatoid arthritis is often diagnosed by the clinician rather than the radiologist. However, in acutely ill patients receiving portable chest radiographs, complete history and laboratory findings are often unavailable. Attention to the thoracic skeleton may clarify pleural and/or parenchymal lung disease in these patients.