St. Jude Medical ($STJ) has launched its Axium Neurostimulator System for dorsal root ganglion (DRG) stimulation to treat patients with chronic pain. The device was approved by the FDA in February. It's intended for use by patients who have uncontrolled pain using traditional spinal cord stimulation (SCS). A pivotal trial found that Axium DRG stimulation provided superior pain relief to traditional tonic SCS. More