INTRODUCTION: Intradiscal electrothermal therapy (IDET) is a controversial, new treatment for low back pain, whose efficacy has not been tested in randomised trials. The present study was undertaken to compare the efficacy of IDET with that of a placebo treatment. METHODS: Patients were recruited by referral and by advertising in the media. Of 4,530 individuals who enquired, 1,360 were prepared to submit to randomisation. Of these, 260 were found potentially eligible after clinical examination, and 64 became eligible after discography. All had discogenic low back pain lasting longer than six months, with no co-morbidity. Thirty-seven were allocated to IDET, and 27 to sham therapy. Both groups were satisfactorily matched for demographic and clinical features. IDET was performed using a standard protocol, in which the posterior annulus of the painful disc was heated to 90°C. Sham therapy consisted of introducing a needle on to the disc and exposing the patient to the same visual and auditory environment as for a real procedure. Follow-up at six months was achieved in over 85% of patients. Pain and disability were assessed using a visual analog scale for pain, the SF-36, the Oswestry disability scale, and the Back Depression Inventory. RESULTS: Patients in both groups exhibited improvements, but improvements in pain, disability, and depression, were significantly greater in the group treated with IDET. Pain scores improved by 24 points in the IDET group compared with 11 in the sham group. Oswestry scores improved by 11 in the IDET group, but only by four in the sham group. More patients deteriorated when subjected to sham treatment, whereas eight patients (25%) achieved greater than 75% relief of pain following IDET. Only one patient did so after sham treatment. The number needed to treat, to achieve 75% relief of pain, was five. No patient suffered any adverse effects. DISCUSSION: IDET fails to provide relief in some 50% of patients. Consequently, its efficacy is difficult to demonstrate statistically. Nevertheless, IDET provides satisfying relief in a substantial proportion of patients. Non-specific factors account for a large proportion of the apparent efficacy of IDET, but its efficacy cannot be attributed wholly to a placebo effect. The efficacy of IDET may be related critically to patient selection and the technique used. Improvements in either of these areas may improve the effect-size of IDET. Meanwhile, IDET is a low risk procedure that constitutes a legitimate option for patients with discogenic low back pain whose only alternative is fusion.
To investigate the efficacy of the navigable intradiscal catheter in the treatment and relief of lumbar discogenic back pain. Twenty-three (23) consecutive patients, at this site, were enrolled into the study by this investigator from normal practice. Inclusion criteria included presentation with predominant low back pain with or without referral leg pain lasting longer than 6 months, diagnosis of DDD or IDD confirmed by plain x-rays, MRI, and positive, low pressure discography, and failure of at least 6 weeks conservative treatment. Outcomes were assessed by clinical exam and administration of the SF-36 Health Survey during the baseline, 3, 6, and 12 month visits. All treatments were performed on an outpatient basis. Following the administration of conscious sedation and local anesthetic, a 17-gauge introducer needle was placed by an extrapedicular approach into the symptomatic disc using fluoroscopic x-ray guidance. A navigable catheter was placed circumferentially to the posterior annular wall. Treatment time was 17 minutes at a maximum tissue temperature of approximately 90°C. Intradiscal antibiotics were employed post procedure and all patients were discharged the day of procedure without complications. Thirty-three (33) lumbar discs were treated. Ten patients had single levels treated; thirteen had double levels treated. Twelve month results show significant improvements in pain as measured by a visual analogue scale (56% decrease, p = 0.035), and the SF-36 sub-scales measuring Bodily Pain (93% decrease, p = 0.011 at 6 months), Physical Functioning (65% increase, p = 0.035), and Role Physical (173% increase, p = 0.020). Overall, 80% of the patients were satisfied with their outcomes (p = 0.004). The intradiscal navigable catheter has proven to be effective in the reduction of pain and an increase in functional abilities for patients who suffer discogenic low back pain due to IDD or DDD.
