The facet joints (joints of the spine), are part of the bony portion of the spinal column connecting vertebral bodies, stabilizing the spine and allowing the spine to move. We use our spine and facet joints with practically every motion of our body, putting these joints at risk of degeneration. These joints may wear down, becoming arthritic and inflamed, which causes severe chronic back pain. A medial branch block or facet joint injection may provide pain relief. The difference between the two injections is merely the placement of the medication, into the actual facet joint or outside the joint space but near the nerve that supplys the joint, called the medial branch. For both injections, the medications given consist of a local anesthetic and possibly a depo-steroid, depending on the treatment plan determined by your pain specialist.