Comparative Effectiveness of a One-Year Follow-Up of Thoracic Medial Branch Blocks in Management of Chronic Thoracic Pain: A Randomized, Double-Blind Active Controlled Trial

Abstract

Background: Thoracic facet joints have been implicated as the source of chronic pain in the mid back or upper back in 34% to 42% of patients when the modified criteria of the International Association for the Study of Pain (IASP) is utilized. Various therapeutic techniques utilized in managing chronic thoracic pain of facet joint origin include intraarticular injections, medial branch blocks, and radiofrequency neurotomy of thoracic medial branch nerves. Study Design: A randomized, double-blind, active controlled trial. Setting: A private practice, interventional pain management setting, and a specialty referral center setting in the United States. Objective: To determine the clinical effectiveness of therapeutic local anesthetic medial branch blocks with or without steroid in managing chronic function-limiting mid back or upper back pain of facet joint origin. Methods: The study was performed in an interventional pain management private practice, a tertiary referral center, in the United States. A total of 100 participants were included, with 50 participants in each of the local anesthetic and steroid groups. All of the participants met the diagnostic criteria of thoracic facet joint pain by means of comparative, controlled diagnostic blocks and the inclusion criteria. Group I participants received thoracic medial branch blocks with bupivacaine, whereas Group II participants received thoracic medial branch blocks with bupivacaine and non-particulate betamethasone. Outcomes Assessment: Outcomes measures included numeric rating scores (NRS), Oswestry Disability Index (ODI), opioid intake, and return to work status at baseline, 3 months, 6 months, and 12 months. Significant pain relief was defined as ≥ 50% pain relief and/or a positive change in ODI scores. Results: In Group I and Group II 90% of participants showed significant pain relief and functional improvement at 12 months. The majority of the participants experienced significant pain relief of 47.2 ± 10.1 weeks in Group I and 46.3 ± 8.4 weeks in Group II, requiring approximately 3.5 treatments per year with an average relief of 15.8 ± 10.5 in Group I and 13.6 ± 3.6 weeks in Group II per episode of treatment. Limitations: Study limitations include the lack of a placebo group. Conclusions: Therapeutic thoracic medial branch blocks, with or without steroid, may provide a management option for chronic function-limiting mid back or upper back pain of facet joint origin. Clinical Trial: NCT00355706 Key words: Chronic spinal pain, thoracic pain, thoracic facet or zygapophysial joint pain, facet joint nerve or medial branch blocks, comparative controlled local anesthetic blocks, therapeutic thoracic medial branch blocks.