effect of the temperature used in thermal radiofrequency ablation

Conditions: Low Back Pain

Summary: this study will determine if lumbar facets medial branches rfa at 90 degrees celsius provides more overall pain relief (i.e., percent of improvement), when compared to ablation at 80 degrees celsius with no additional adverse events.

chronic lower back pain (clbp) is a significant health care issue in the united states and the world. clbp contributes to decreased quality of life, decreased function and increased utilization of health care resources. the causes of clbp tend to be multi-factorial. arthropathy of the lumbar facet joints is thought to be a common etiology (15-45%). radiofrequency ablation (rfa) of the medial branch nerve of the facet joint is a well-established treatment modality used to decrease facet joint pains. however, a wide range of temperature is being used (70-90 degrees celsius). in addition, the optimal temperature that provides the best patient outcomes with the least side effects is not well established in the pain management literature. this study will determine if lumbar facets medial branches rfa at 90 degrees celsius provides more overall pain relief (i.e., percent of improvement), when compared to ablation at 80 degrees celsius with no additional adverse events. furthermore, ablation of the lumbar facets nerve supply at 90 degrees celsius will provide better improvement in the functionality level, general mood and quality of life as measured by vas ( visual analog scale) pain score, pain disability index (pdi), mcgill pain questioner scores and beck inventory (bi) scores as those receiving the ablation at 80 degrees celsius. also, it is associated with less opioid consumption, no additional unwanted adverse events and/or complications along with less need to repeat rfa procedure over one year period.

Eligibility criteria:
inclusion criteria: * age \>18 years-old * subjects who are able to give informed consent and to understand and comply with study requirements. * predominantly axial low back pain ≥ 3 months in duration with no radicular pain below the knee that failed to conservative therapy. * subjects who have chronic back pain attributed to lumbar facet joints arthropathy based on clinical evaluation (paraspinal tenderness and/or facet loading test in the absence of signs and symptoms suggestive of focal neurological deficits). * no history of previous back surgery at the intended treatment levels. * adequate response to the diagnostic blocks without the use of steroids at the same levels of the intended block (defined as ≥ 75% pain relief). * patients who will undergo rfa of 3-4 lumbar facet medial branches on one side only. exclusion criteria: * subjects who decline to provide written consent or follow-up. * subjects who have a history of adverse reactions to local anesthetic. * subjects who are pregnant. * subjects with bleeding disorders or active anticoagulation that cannot be stopped for few days close to the time of the procedure. * subjects who have an active systemic or local infection. * presence of radicular pain below the knee. * patients who have other specific etiology of low back pain (e.g. significant spinal canal stenosis or grade 2 or 3 spondylolisthesis). * secondary gain (i.e., ongoing litigation, worker's compensation or other financial incentives) * psychopathology including depression, somatization or poor coping skills * physical factors including non-sedentary lifestyle, e.g.; morbid obesity (bmi \> 35kg/m2). * history of previous rfa at the same level(s) in the previous 12 months.