Effectiveness of thermal annular procedures in treating discogenic low back pain.

BACKGROUND Persistent low back pain refractory to conservative treatment is a common problem that leads to widespread impairment, resulting in significant costs to society. The intervertebral disc is a major source of persistent low back pain. Technologies developed to treat this problem, including various surgical instrumentation and fusion techniques, have not reliably provided satisfactory results in terms of either pain relief or increased function. Thermal annular procedures (TAPs) were first developed in the late 1990s in an attempt to treat discogenic pain. The hope was that they would provide greater value than fusion in terms of efficacy, morbidity, and cost. Three technologies have been developed to apply heat to the annulus: intradiscal electrothermal therapy (IDET), discTRODE, and biacuplasty. Since nerve ingrowth and tissue regeneration in the annulus is felt to be the source of pain in discogenic low back pain, when describing the 3 above techniques we use the term "thermal annular procedures" rather than "thermal intradiscal procedures. " We have specifically excluded studies treating the nucleus. TAPs have been the subject of significant controversy. Multiple reviews have been conducted resulting in varying conclusions. STUDY DESIGN A systematic review of TAPs for the treatment of discogenic low back pain. OBJECTIVE To evaluate the effectiveness of TAPs in treating discogenic low back pain and to assess complications associated with those procedures. METHODS The available literature on TAPs in treating discogenic low back pain was reviewed. The quality assessment and clinical relevance criteria utilized were the Cochrane Musculoskeletal Review Group criteria for interventional techniques for randomized trials, and the criteria developed by the Newcastle-Ottawa Scale criteria for observational studies. The level of evidence was classified as good, fair, or poor based on the quality of evidence developed by the U.S. Preventive Services Task Force. Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 through December 2011, and manual searches of the bibliographies of known primary and review articles. OUTCOME MEASURES The primary outcome measure was pain relief of at least 6 months. Secondary outcome measures were improvements in functional status. RESULTS For this systematic review, 43 studies were identified. Of these, 3 randomized controlled trials and one observational study met the inclusion criteria. Using current criteria for successful outcomes, the evidence is fair for IDET and poor for discTRODE and biacuplasty procedures regarding whether they are effective in relieving discogenic low back pain. Since 2 randomized controlled trials are in progress on that procedure, assessment of biacuplasty may change upon publication of those studies. LIMITATIONS The limitations of this systematic review include the paucity of literature and non-availability of 2 randomized trials which are in progress for biacuplasty. CONCLUSION In summary, the evidence is fair for IDET and poor for discTRODE and biacuplasty is being evaluated in 2 ongoing randomized controlled trials.