Computed tomography in sternocostoclavicular hyperostosis.

Sternocostoclavicular hyperostosis is a rare but recognized entity characterized by new bone formation and ligamentous ossification which limits mobility of the sternoclavicular joints. Aetiology is obscure and debated. There may be considerable delay in establishing the diagnosis, even by specialists. In confirming the diagnosis plain radiography is of limited value but radionuclide bone scan and computed tomography (CT) may be helpful. Four cases are described to emphasize these points and illustrate the clinical and radiological features of the condition. High resolution CT with thin sections (5 mm or less) is the examination of choice for demonstrating the characteristic features and is essential if the condition is to be confirmed in its early stages when treatment might be more successful in delaying progression.