Sonography of the acromioclavicular joint

Although standardized sonographic techniques are available, the diagnostic capabilities of sonography in diseases and injuries of the acromioclavicular [AC] joint are not yet widely used. Nevertheless, standardized sonographic techniques are available for examining injuries and diseases of the AC joint. Analogous to X-ray techniques,the bony relations of the clavicle and the acromion can be displayed. Joint effusions and marginal alterations of the subchondral bone plate can be imaged. However, there is no reliable method to display the articular disc and the coracoclavicular ligaments. There is no reproducible method for displaying the articular disk. Tears of the deltoid and trapezius muscles and their common fascia are easily detectable in high-grade injuries of the AC joint. The differentiation between ac-joint injuries, i.e. Rockwood II/Rockwood IV, is facilitated, which aids in therapeutic decision making. In combination with conventional X-ray examination, sonography of the AC joint can be used at low cost and is easy to learn.