[High resolution ultrasound diagnosis of the annular tendon system of the hand]

High-resolution ultrasonography has gained wide acceptance in the evaluation of tendons and tendon sheaths of the finger flexors. The annular pulleys are depicted as a hypoechoic band surrounding the flexor tendons. In patients with trigger finger or polyarthritis, the tendons as well as the pulleys are of interest to the investigator. Ultrasonography allows direct or indirect diagnosis of partial and total disruptions of the pulleys. Loss of (parts of) the pulleys can be seen as a direct sign and bowstringing of the tendons during forced flexion as an indirect sign. We provide a review of the literature regarding this topic and present our experiences with better visualization employing the latest ultrasonographic equipment (such as Sono-CT).