Two-year results from the Intradiscal Electrothermal Therapy nationwide registry

Abstract

Kerry Thompson, MD, Timothy Eckel, MD, Annapolis, MD, USAIntroduction: Discogenic low back pain has a variety of causes, one of which is the natural degeneration of the disc. To treat pain associated with disc degeneration, there are a variety of conservative therapy options, including medication, bed rest and physical therapy. When these treatments fail to adequately improve low back pain, Intradiscal Electrothermal Therapy (IDET) is available to these patients as a treatment option for degenerative disc disease. The sponsor, ORATEC Interventions, Inc., to study patient outcomes through a 2-year period after IDET, initiated a nationwide registry in 1998. This study evaluates outcomes for the first 100 patients with completed 2-year assessments.Materials and methods: Qualified physicians who received training from the sponsor were asked to participate in the IDET registry. Data was collected on a prospective, voluntary basis. The patient pretreatment assessment included the SF-36 questionnaire; a Visual Analog Scale (VAS) pain evaluation; sitting, standing and walking tolerances and patient demographics. The physician provided treatment information and basic clinical characteristics of each patient. The sponsor mailed follow-up questionnaires, including the outcome measures previously listed, to the patient at 6 months, 1 year and 2 years after treatment. Matched pairs analyses were used to compare pretreatment status and 2-year outcomes.Results: As of February 2001, a 67% response rate has been observed. Forty-five percent of the patients had a single disc level treated, whereas 36% had two levels and 19% had three levels treated. Fifty-four percent of the patients were female and 53% were ages 18 to 44 years. The mean duration of symptoms before treatment was 38.5 months (standard deviation, 51.3 months). Table 1Table 1OutcomePre-Treatment mean ± std24 Month mean ± stdChange mean ± stdp ValueVisual Analog Scale6.7 ± 1.73.6 ± 2.93.1 ± 2.7<.0001SF-36Physical Function36.6 ± 23.162.1 ± 28.425.3 ± 27.7<.0001Bodily pain26.1 ± 16.049.2 ± 30.025.2 ± 30.6<.0001Role Emotional45.5 ± 43.268.4 ± 43.220.4 ± 41.0.0094Role Physical9.1 ± 22.445.0 ± 45.034.7 ± 47.3.0003Social Function38.6 ± 25.363.8 ± 35.025.0 ± 30.1.0001Mental Health50.9 ± 22.166.3 ± 20.516.6 ± 22.8.0175General Health67.5 ± 21.765.6 ± 26.50.2 ± 22.8.9620Vitality33.7 ± 20.349.7 ± 23.915.8 ± 23.2.0099Sitting (min)34.6 ± 35.677.3 ± 52.841.8 ± 44.6<.0001Standing (min)31.9 ± 36.754.8 ± 47.223.2 ± 44.0.0049Walking (min)32.3 ± 27.665.2 ± 52.132.7 ± 41.0<.0001 summarizes the 2-year outcomes. Eighty-one percent of the patients reported that their health was “somewhat” or “much better” compared with their status before IDET. Eighty-three percent would “probably” or “definitely” choose the same treatment for their low back pain. Sixty-six percent of the patients reported they were using less medication at 24 months after IDET when compared with pretreatment medication usage (Table 1).Conclusion: At 2 years after IDET, a significant improvement in physical functioning as evidenced by the Physical Function and Role Physical Scales of the SF-36, as well as sitting, standing and walking tolerances, was observed. A significant reduction in pain was demonstrated using the VAS and the Bodily Pain Scale of the SF-36. Overall quality of life was significantly improved. More than 80% of the patients reported they were satisfied with the procedure. IDET is an effective means of treating patients with discogenic low back pain.