[Ultrasound diagnosis of the rotator cuff]

Shoulder sonography is a well-established and standardized method to evaluate the status of the rotator cuff, the long head of the biceps, and the subacromial and subdeltoid bursae. Using high-frequency linear probes, the sensitivity in detecting total tears sized 0.5 cm and greater is > 90% and in detecting partial thickness tears of at least one-third of the cuff substance > 75% when using the dual-criteria standard. Ultrasound achieves comparable or better results than native magnetic resonance tomography at far less cost. False results can be excluded in the majority of cases by strict adherence to a dual-criteria model. The ability to display the joint's soft tissue structures in real time is unique up to now. The limits of sonography are (1) in the estimation of tear size in global tears as retraction of tendon stumps under the acromion cannot be visualized and (2) in the evaluation of status of rotator cuff muscles since volumetric information about atrophy can be gained by ultrasonography, but a differentiation between simple atrophy and fatty degeneration is not possible.