Evaluation of the prevalence of facet joint pain in chronic thoracic pain.

The role of zygapophysial (facet) joints in chronic thoracic pain has received very little attention with only a few publications discussing these joints as sources of pain. In contrast, facet joints have been implicated as responsible for chronic pain in a significant proportion of patients with chronic neck and low back pain. However, thoracic spinal pain, though less common, has been reported to be as disabling as neck and low back pain. This study was designed to evaluate all the consecutive patients presenting with thoracic pain and undergoing diagnostic medial branch blocks during 2001. All the patients failed conservative management with physical therapy, chiropractic therapy and drug therapy. All patients underwent diagnostic facet joint nerve blocks using lidocaine 1%, initially followed by bupivacaine 0.5% on separate occasions. Results showed that 46 patients underwent single blocks with lidocaine and 36 of these patients, or 78%, were positive for facet joint pain, reporting a definite response. Confirmatory blocks with bupivacaine were performed in all patients who were lidocaine-positive, with 61%, or 48% of the total sample of the lidocaine-positive group, reporting a definite response with improvement in their pain. Thus, comparative local anesthetic blocks showed the prevalence of facet joint pain to be 48%, with single blocks carrying a false-positive rate of 58%.