New directions and interventions: intradiscal electrothermal annuloplasty to treat chronic discogenic low back pain

Abstract

Preliminary data on the clinical efficacy of intradiscal electrothermal annuloplasty (IDET) are reviewed, along with the methodologic strengths of studies to date. All studies share a common study design: prospective cohort, with historical or noninterventional groups as controls. Similar patients are reviewed: those with nonradicular low back pain of at least 3 months' duration, failed conservative care, normal neurologic findings, magnetic resonance imaging revealing only nondegenerative disc disease, and positive concordant discography. All patients underwent IDET lesion at one or two levels based on standard protocols. Follow-up was performed at various intervals up to 2 years. All studies used data from the Visual Analogue Scale, with most using the Short Form–36 Health Status Questionnaire as an outcome instrument as well. Three published studies, Saal and Saal (6-month follow-up), Saal and Saal (1-year follow-up), and Karasek and Bogduk (1-year follow-up) were published in the peer-reviewed literature. Two recent reports presented at the North American Spine Society, Thompson and Eckel (1-year follow-up of patients on a manufactured sponsored registry), and the multicenter prospective cohort study of Wetzel et al. (75 patients in the intent-to-treat group, some with 2-year follow-up) are reviewed. All studies suggested a positive effect of treatment with a decrease in Visual Analogue Scale ratings and improvement in Short Form–36 scales, particularly physical function and bodily pain, using the 7-point criteria of Deyo et al. Based on the studies published to date, there is a suggestion that the pain due to lumbar disc disease may be diminished by IDET. All studies to date suggest a positive therapeutic effect. However, all studies suffer from the same methodologic flaws, with a prospective cohort design or a nonrandomized prospective design with a biased control. Additionally, more investigation into the basic science of IDET is required.