Spinal Cord Stimulator

Hi:I have been having major pain in my foot, on and off for the last few years, broken bones, torn ligaments etc… have tried the nerve blocks, and many different things, with no relief, and they are suggesting a spinal cord stimulator to assist with pain control.
I am waiting for an appointment with a new pain management clinic, to discuss this, do you know how dangerous or how affective this is???-Kolleen