865 - Radiofrequency ablation of the thoracic descending branch of the posterior rami - an effective intervention for thoracic facet joint pain

Case Diagnosis: Two instances of bilateral fluoroscopic-guided T4-6 descending branch (DB) nerve blocks were performed with 0.5 mL of 2% Lidocaine and 0.5 mL of 0.5% Bupivacaine respectively which yielded more than 80% temporary pain relief, thus establishing the diagnosis of thoracic facet joint pain.

Case Description: A 57-year-old female presented with a four-month history of severe mid-thoracic back pain. The patient failed initial conservative treatment including oral pain medications and physical therapy for three months and ultimately elected for two diagnostic block of bilateral T4-6 DBs of the posterior rami and subsequent thermal radiofrequency ablation (RFA) which resulted in complete pain relief and functional improvement. The patient followed-up approximately two years after her last RFA treatment and continued to report complete relief of her thoracic back pain.

Discussions: The decision to perform a DB block, and subsequent RFA, on our patient was primarily driven by the variable results of pain outcomes status post MB RFA with addition to our increasing understanding of the neuroanatomy of the thoracic facet joint. Prior studies have shown that the posterior ramus of the thoracic nerve sends out the DB prior to bifurcating into the medial and lateral branches and that the articular branch entering the thoracic facet joint originated from the DB. We hypothesize that the variable results, low success rate, and short duration of relief following a MB RFA could be possibly due to the DB not being targeted by the RFA technique.

Conclusions: This is the first case report on RFA of the descending branch of the posterior ramus in the thoracic spine that provided effective and long-term pain relief for thoracic facet joint pain. This novel approach should be studied further, ideally in a randomized fashion on a large patient population in order to confirm the clinical efficacy of this approach.