Chronic neck and back pain has become one of the leading causes of disability and loss of productivity. For many patients with facet or sacroiliac joint mediated pain who have responded to diagnostic nerve blocks, radiofrequency ablation of the nerves innervating the joints can provide long term relief. Radiofrequency ablation (RFA) is a relatively safe procedure with minimal risk of adverse events. However, with any procedure involving damage to the peripheral nervous system, there is risk of post-procedure neuropathic pain. The investigators will test the hypothesis that dexamethasone injection delivered at the time of lesion effectively prevents the development of post-ablation neuritis through a placebo-controlled, double-blind, randomized trial in patients undergoing cervical, thoracic, lumbar, and sacroiliac joint radiofrequency denervations