Background: Lumbar facet joints are a well recognized source of low back pain and referred pain in the lower extremity in patients with chronic low back pain. Conventional clinical features and other non-invasive diagnostic modalities are unreliable in diagnosing lumbar zygapophysial joint pain. Controlled diagnostic studies have shown the prevalence of lumbar facet joint pain in 27% to 40% of the patients with chronic low back pain without disc displacement or radiculitis, with a false-positive rate of 27% to 47% with a single diagnostic block.
Study design: A systematic review of diagnostic and therapeutic lumbar facet joint interventions.
Objective: To determine the clinical utility of diagnostic and therapeutic lumbar facet joint interventions in managing chronic low back pain of facet joint origin.
Methods: Review of the literature for clinical studies on efficacy and utility of facet joint interventions in diagnosing and managing facet joint pain was performed according to the Agency for Healthcare Research and Quality (AHRQ) criteria for diagnostic studies and observational studies and the Cochrane Musculoskeletal Review Group criteria as utilized for interventional techniques for randomized trials. Data sources included relevant literature of the English language identified through searches of Medline and EMBASE from 1966 to December 2008 and manual searches of bibliographies of known primary and review articles. Analysis results were performed for diagnostic and therapeutic interventions separately.
Level of evidence: The level of evidence was defined as Level I, II, or III with 3 subcategories in Level II based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF) for therapeutic interventions.
Outcome measures: For diagnostic interventions, studies must have been performed utilizing controlled local anesthetic blocks. Pain relief was categorized as at least 80% pain relief from baseline pain and ability to perform previously painful movements. For therapeutic interventions, the primary outcome measure was pain relief with secondary outcome measures of improvement in functional status, psychological status, return to work, and reduction in opioid intake. For therapeutic interventions, short-term pain relief was defined as relief lasting 6 months or less and long-term relief as longer than 6 months.
Results: Based on USPSTF criteria, evidence showed Level I or II-1 for diagnostic facet joint nerve blocks. Based on the review of included therapeutic studies, Level II-1 to II-2 evidence was indicated for lumbar facet joint nerve blocks with indicated level of evidence of Level II-2 to II-3 for lumbar radiofrequency neurotomy.
Limitations: The shortcoming of this systematic review of lumbar facet joint interventions is the paucity of published literature.
Conclusion: The evidence for diagnosis of lumbar facet joint pain with controlled local anesthetic blocks is Level I or II-1. The indicated level of evidence for therapeutic lumbar facet joint interventions is Level II-1 or II-2 for lumbar facet joint nerve blocks, Level II-2 or II-3 evidence for radiofrequency neurotomy, and Level III (limited) evidence for intraarticular injections.