Thoracic spine

The prevalence of diagnosed chronic pain in the thoracic spine is lower than that of the cervical and lumbar spine. However, when present, it can be attributed to the involvement of the thoracic zygapophysial joint in approximately 50% of patients. As with their cervical and lumbar counterparts, sensory signals from the thoracic zygapophyseal joints are relayed through nerve endings that converge in the medial branches of the primary posterior rami and then to the ascending pain network. This pain generator typically presents as paravertebral tenderness that is aggravated by prolonged standing, hyperextension, or rotation of the thoracic spine and can be effectively identified with nerve blockade of the ramus medialis of the thoracic rami dorsalis. Until the late 1990s, the anatomical location of the thoracic medial branches was assumed to be analogous to the lumbar spine, but advances in anatomical knowledge coupled with further anatomical research have allowed for modification of techniques, improved diagnostic accuracy, and treatment outcomes when targeting these structures. In order to improve the quality and efficacy of radiofrequency ablation for thoracic facet-mediated pain, it is imperative to appreciate the anatomical differences in the thoracic spine. This chapter explores the science supporting the currently recommended interventional techniques for the diagnosis, through anesthetic blockade, and for the treatment of thoracic facet-mediated pain with radiofrequency denervation of the medial branches.