A RANDOMIZED DOUBLE-BLIND PLACEBO CONTROLLED EFFICACY STUDY OF INTRADISCAL ELECTROTHERMAL THERAPY FOR THE TREATMENT OF CHRONIC DISCOGENIC LOW BACK PAIN

Abstract

Introduction: Intra-Discal Electrothermal Therapy (IDET) has been proposed as a treatment for chronic discogenic low back pain. Reports from prospective outcome studies demonstrate statistically significant improvements, but there are no published randomized controlled trials assessing efficacy against a placebo group.

Methods: Ethical committee approval was obtained prior to the study. Patients with chronic low back pain who failed conservative treatment were considered for the study. Inclusion criteria included one or two level symptomatic internal disc disruption as determined by provocative CT/discography. Patients were excluded if there was > 50% loss of disc height or had had previous back surgery. Fifty-seven patients were randomized with a 2:1 (IDET: Placebo) ratio, 38 to the active IDET arm and 19 to the sham (placebo). The IDET catheter was positioned under sedation to cover at least 75% of the annular tear as defined by the CT/discogram. An independent technician connected the catheter to the generator and either delivered electrothermal energy (active group) or did not (sham group). Surgeon, patient and independent outcome assessor were all blinded. All patients followed a standard rehabilitation programme.

Outcome Measures: Low Back Outcome Score (LBOS), Oswestry Disability Index (ODI), SF-36 questionnaire, Zung Depression Index (ZDI) and Modified Somatic Perceptions Questionnaire (MSPQ) were measured at baseline and 6 months. Successful outcome was defined as: No neurological deficit resulting from the procedure, improvement > 7 points in LBOS, improvements > 7 points in SF-36 subsets (pain / disability, physical functioning and bodily pain)

Results: Two subjects withdrew from the study (both IDET). Baseline demographic data, employment and worker’s compensation status, sitting tolerance, initial LBOS, ODI, SF-36, ZDI and MSPQ were similar for both groups. No neurological deficits occurred as a result of either procedure. No subject in either treatment arm showed improvement of > 7 points in LBOS or the specified domains of the SF-36. Mean ODI was 41.4 at baseline and 39.7 at 6 months for the IDET group compared to 40.7 at baseline and 41.5 at six months for the Placebo group. There was no significant change in ZDI or MSPQ scores for either group.

Discussion: No subject in either treatment arm met criteria for successful outcome. There was no significant change in outcome measures in either group at six months. This study demonstrates no significant benefit from IDET over placebo.