Osteoarthritis of the sternoclavicular joint. Radiographic features and pathologic correlation.

Osteoarthritis (OA) of the sternoclavicular (SC) joint has been extensively characterized in the pathology literature, but the radiographic appearance of this entity has received comparatively little attention. To define the radiographic patterns of OA at this joint, we used high resolution PA radiographs (industrial grade film) to examine 55 SC joints obtained by block resection at autopsy. Ten of these also were selected for coronal complex motion tomography. Fifty cases were histologically correlated. Radiographic and pathologic material was evaluated by four criteria characteristic of OA: joint-space narrowing, osteophytes, sclerosis, and cysts. Each criterion was independently assessed for severity and distribution. Moderate or severe radiographic changes of OA were uncommon in specimens younger than age 40, but present in 53% older than age 60. Changes were typically bilateral, although a mild degree of asymmetry was common. OA was most severe along the inferior portion of the clavicular head, which comprises its articulating margin with the sternum. Complex motion tomography was generally more accurate than plain radiography for assessing OA in the ten specimens in which comparison was performed.