Effectiveness of thoracic medial branch blocks in managing chronic pain: a preliminary report of a randomized, double-blind controlled trial.

BACKGROUND: Thoracic facet joints have been implicated as the source of chronic pain in the mid back or upper back in 34% to 48% of the patients. Various therapeutic techniques utilized in managing chronic thoracic pain of facet joint origin include intraarticular injections, medial branch blocks, and radiofrequency neurotomy of thoracic facet joint nerves.

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.

DESIGN: A randomized, double-blind, controlled trial.

SETTING: An interventional pain management private practice, a tertiary referral center, in the United States.

METHODS: A total of 48 patients were included, with 24 patients in each of the local anesthetic and steroid groups. All of the patients met the diagnostic criteria of thoracic facet joint pain by means of comparative, controlled diagnostic blocks and the inclusion criteria. Group I patients received thoracic medial branch blocks with bupivacaine, whereas Group II patients received thoracic medial branch blocks with bupivacaine and non-particulate betamethasone.

OUTCOME MEASURES: Numeric pain scores (NRS), Oswestry Disability Index (ODI), opioid intake, and return to work status. All outcomes were assessed at baseline, 3 months, 6 months, and 12 months. Significant pain relief was defined as > 50% pain relief. Significant functional improvement was defined as 40% reduction of ODI.

RESULTS: In Group I, 79% of patients showed significant pain relief and functional improvement at 3 months, 6 months, and 12 months, a significant change from baseline. In Group II, 83%, 81%, and 79% of patients showed significant pain relief and functional improvement at 3 months, 6 months, and 12 months, a significant change from baseline. The majority of the patients experienced significant pain relief of 46 to 50 weeks, requiring approximately 3 to 4 treatments with an average relief of 16 weeks per episode of treatment.

CONCLUSION: The majority of the patients in both groups experienced significant pain relief and improvement in functional status. 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.