Ultrasonography in pain medicine: a critical review.

Recently, ultrasonography has been increasingly used in the field of regional anesthesia to assure reliable blockade of peripheral nerves and to visualize neuroaxial structures. As its popularity is steadily increasing, it may become a standard of care for both intraoperative analgesia and postoperative pain control. The application of ultrasound in chronic pain management, however, remains underutilized. Multiple reasons can be suggested to explain this situation. Nonetheless, numerous articles have been published and some interventionalists have gained experience and started to spread their knowledge through hands-on workshops and medical meetings. It, therefore, seems timely to describe the techniques of ultrasound-guided injections for chronic pain, to review accumulated experience in this field, to reappraise the scientific and clinical value of this method, and to outline potential future developments.