Osteochondroma of the distal clavicle: an unusual cause of rotator cuff impingement.

Rotator cuff impingement symptoms may arise from intrinsic pathologic shoulder lesions related to instability or from extrinsic factors, primarily involving the coracoacromial arch. This report describes 2 unusual cases in which extrinsic impingement resulted from a distal clavicular osteochondroma. In both cases symptoms resolved after resection of the osteochondroma.