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 limited (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 limited (or 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 nonavailability of 2 randomized trials which are in progress for biacuplasty.
Conclusion: In summary, the evidence is fair for IDET and limited (or poor) for discTRODE and
biacuplasty is being evaluated in 2 ongoing randomized controlled trials.
Key words: Spinal pain, chronic low back pain, discogenic pain, thermal procedures, annular
procedures, IDET, biaculoplasty, disctrode