Ultrasonography of the shoulder.

The shoulder is the most common region to be evaluated with musculoskeletal ultrasound. The shoulder's complex anatomy enables an exceptional range of mobility at the expense of static stability. Consequently, the shoulder is susceptible to a multitude of traumatic and atraumatic injuries. This article presents an overview of shoulder anatomy, recommends a standardized approach to the sonographic shoulder evaluation, and discusses common sonographically apparent pathology of the shoulder.