A little-known cause of painful shoulder: os acromiale

The incidental discovery of an 'os acromiale' might explain some cases of 'painful shoulder': this is what we have observed in three patients. The purpose of our article is to underline the relevance of the axillary roentgenogram of the shoulder for the correct diagnosis of this anomaly. In all patients the radiographic examination was performed using a computed radiography system; moreover we performed a computed tomographic examination of the acromioclavicular portion of the shoulders with three-dimensional reconstructions.