Radiofrequency denervation of the medial branch of the dorsal ramus of the lumbar facet joint with a three-tined expandable needle.

The primary outcome of this study is pain measured with the numeric rating score (NRS): 11-point NRS ranging from 0 (no pain at all) to 10 (the worst imaginable pain). A score of zero (0) will indicate that the patient is pain free, while a score of ten (10) will indicate that they are experiencing the worst pain imaginable.

The PGIC rating is increasingly being used for determining clinically important change in measures such as ratings of pain. This scale is designed to quantify patient's improvement or deterioration over time, usually either to determine the effect of an intervention or to chart the clinical course of a condition. The scales ask that a person assess his or her current pain, recall that status at a previous time-point, and then calculate the difference between the two.