Diagnostic accuracy of thoracic facet joint nerve blocks: an update of the assessment of evidence.

BACKGROUND Chronic mid back and upper back pain caused by thoracic facet joints has been reported in 34% to 48% of the patients based on their responses to controlled diagnostic blocks. Systematic reviews have established moderate evidence for controlled comparative local anesthetic blocks of thoracic facet joints in the diagnosis of mid back and upper back pain. OBJECTIVE To determine the diagnostic accuracy of thoracic facet joint nerve blocks in the assessment of chronic upper back and mid back pain. STUDY DESIGN Systematic review of the diagnostic accuracy of thoracic facet joint nerve blocks. METHODS A methodological quality assessment of included studies was performed using Quality Appraisal of Reliability Studies (QAREL). Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. Studies scoring less than 50% are presented descriptively and critically analyzed. The level of evidence was classified as good, fair, and limited (or poor) based on the quality of evidence developed by the United States Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to March 2012, and manual searches of the bibliographies of known primary and review articles. OUTCOME MEASURES Controlled placebo or local anesthetic blocks were utilized using at least 50% pain relief as the reference standard. RESULTS Three studies were identified utilizing controlled comparative local anesthetic blocks, with ≥ 50% pain relief as the criterion standard. The evidence is good for the diagnosis of thoracic pain of facet joint origin with controlled diagnostic blocks. LIMITATIONS The limitations of this systematic review include a paucity of literature for the diagnosis of thoracic facet joint pain, with all included manuscripts originating from one group of authors. CONCLUSIONS Based on this systematic review, the evidence for the diagnostic accuracy of thoracic facet joint injections is good.