A RANDOMIZED DOUBLE-BLIND CONTROLLED EFFICACY STUDY: INTRADISCAL ELECTROTHERMAL THERAPY (IDET) VERSUS PLACEBO FOR CHRONIC DISCOGENIC LOW BACK PAIN

Abstract

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 to date there are no published randomized controlled trials assessing efficacy when compared to a placebo group.

Ethical Committee approval was obtained prior to the study. Patients with chronic low back pain who failed to improve with conservative therapy were considered for the study. Subjects had one or two level symptomatic disc degeneration as determined by provocative CT/discography. Patients were excluded if there was > 50% loss of disc height or 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 procedure (placebo). In all cases the IDET catheter was positioned under sedation to cover at least 70% of the annular tear 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). Both surgeon and patient were blinded to the treatment. Patients followed a standard rehabilitation programme.

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 in LBOS of > 7 points, improvements in SF-36 subsets (pain/disability, physical functioning and bodily pain).

Two subjects withdrew (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 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 for either group. No subject in either treatment arm met criteria for successful outcome. Further analysis showed no significant change in outcome measures in either group at six months.

In conclusion, this study demonstrates no significant benefit from IDET over placebo.