Treatment of chronic lumbar diskogenic pain with intradiskal electrothermal therapy: a prospective outcome study

Results of intradiscal pulsed radiofrequency for lumbar discogenic pain: comparison with intradiscal electrothermal therapy

Background

We have developed an intradiscal pulsed radiofrequency (Disc PRF) technique, using Diskit II® needles (NeuroTherm, Wilmington, MA, USA), as a minimally invasive treatment option for chronic discogenic low back pain (LBP). The purpose of this study was to compare the representative outcomes of Disc PRF and Intradiscal Electrothermal Therapy (IDET) in terms of pain relief and reduction of disability.

Methods

Thirty-one patients with chronic discogenic LBP who underwent either Disc PRF (n = 15) or IDET (n = 16) were enrolled in the study. A Diskit II® needle (15-cm length, 20-gauge needle with a 20-mm active tip) was placed centrally in the disc. PRF was applied for 15 min at a setting of 5 × 50 ms/s and 60 V. The pain intensity score on a 0-10 numeric rating scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ) were assessed pretreatment and at 1, 3, and 6 months post-treatment.

Results

The mean NRS was significantly improved from 7.2 ± 0.6 pretreatment to 2.5 ± 0.9 in the Disc PRF group, and from 7.5 ± 1.0 to 1.7 ± 1.5 in the IDET group, at the 6-month follow-up. The mean RMDQ also showed significant improvement in both the Disc PRF group and the IDET group at the 6-month follow-up. There were no significant differences in the pretreatment NRS and RMDQ scores between the groups.

Conclusions

Disc PRF appears to be an alternative to IDET as a safe, minimally invasive treatment option for patients with chronic discogenic LBP.

Long-term reduction in pain and disability after surgery with the interspinous device for intervertebral assisted motion (DIAM) spinal stabilization system in patients with low back pain: 4-year follow-up from a longitudinal prospective case series

Patients with low back pain (LBP) suffer chronic disability. In 40% of LBP patients degenerative disc disease (DDD) seems to be the cause. This prospective case series assessed the efficacy of the interspinous device for intervertebral assisted motion (DIAM™) in patients with LBP resulting from DDD. All patients were initially assessed by physical examinations, magnetic resonance imaging, dynamic X-rays and provocative discography. Eligible patients (n = 52) had LBP for a minimum of 4 months, and received surgery with the DIAM™ system 2-4 weeks after diagnosis. Patients were evaluated pre-/post-operatively for pain severity using a visual analogue scale (VAS), and for dysfunction and disability with the Roland-Morris Disability Questionnaire (RMDQ). VAS and RMDQ score changes were assessed using the appropriate contrasts and Bonferroni-corrected P values. As a result, significant (P < 0.0001) pain score reductions were observed between baseline values, and 2 (3.7, 95% CI 3.1; 4.2) and 48 (3.1, 95% CI 2.5; 3.6) months follow-up (intent-to-treat population). Disability scores were significantly (P < 0.0001) reduced between baseline and 2 (8.6, 95% CI 7.4; 9.9) and 48 (7.5, 95% CI 6.1; 8.9) months. Disability scores were similar from months 2 to 48. At 48 months, 67.3% of patients reached the minimum clinically important difference (MCID; ≥1.5-unit improvement) in VAS score and 78.9% of patients reached the MCID (≥30% improvement) in RMDQ score. No complications were associated with surgery. In conclusion, patients with LBP treated with the interspinous DIAM™ system showed significant and clinically meaningful improvements in pain and disability for up to 4 years.

DIAM device for low back pain in degenerative disc disease : 24 months follow-up

PURPOSE

To evaluate the usefulness of the DIAM device in patients affected by low back pain due to degenerative disc disease.

BACKGROUND

Recently a number of interspinous devices for dynamic interspinous distraction-stabilization have entered the clinical practice in Europe. All of these devices have a common property of acting on the posterior part of the functional spinal unit by distracting the spinous processes and avoiding extension of the treated segment. Consequently, these systems seem to improve the cross-sectional area of the thecal sac and enlarge the diameter of the intervertebral foramina. What was found as a collateral observation after implantation of these devices was that those patients affected by low back pain, improved significantly in their pain level.

METHODS AND MATERIALS

Fifty-two consecutive patients were included in the study. There were 29 females and 23 males, aged between 29 and 77 years (mean 49.4 ± s.d. 12.4). The pre-operative symptom duration ranged from 6 to 84 months (mean 31.8 ± s.d. 20.2, median 24 months).The following diagnostic measures were performed in each patient: MRI, dynamic X-rays and provocative discography positive for pain reproduction.The patients were followed for pain by VAS and for functional status by self-reported Roland-Morris Disability Questionnaire. The minimum follow-up was 24 months (24-36). The intermediate follow-up at 6, 12 and 18 months was tested for, too.

RESULTS

To determine the number of improved patients we have arbitrarily selected a cut-off criteria based on a ≥30% of improvement as calculated on the Roland Morris Disability Questionnaire scale comparing the 24 months values to the baseline values. Forty-six patients (88%) were considered as success and 2 (4%) were considered as failure. No long-term complications were observed.

CONCLUSIONS

This preliminary report indicates that the DIAM device could possibly be useful in the treatment of LBP due to DDD. Further research with RCT is necessary to confirm these preliminary results.

Intervertebral disc: anatomy-physiology-pathophysiology-treatment

This review article describes anatomy, physiology, pathophysiology and treatment of intervertebral disc. The intervertebral discs lie between the vertebral bodies, linking them together. The components of the disc are nucleus pulposus, annulus fibrosus and cartilagenous end-plates. The blood supply to the disc is only to the cartilagenous end-plates. The nerve supply is basically through the sinovertebral nerve. Biochemically, the important constituents of the disc are collagen fibers, elastin fibers and aggrecan. As the disc ages, degeneration occurs, osmotic pressure is lost in the nucleus, dehydration occurs, and the disc loses its height. During these changes, nociceptive nuclear material tracks and leaks through the outer rim of the annulus. This is the main source of discogenic pain. While this is occurring, the degenerative disc, having lost its height, effects the structures close by, such as ligamentum flavum, facet joints, and the shape of the neural foramina. This is the main cause of spinal stenosis and radicular pain due to the disc degeneration in the aged populations. Diagnosis is done by a strict protocol and treatment options are described in this review. The rationale for new therapies are to substitute the biochemical constituents, or augment nucleus pulposus or regenerate cartilaginous end-plate or finally artificial disc implantation..

Evidence-informed management of chronic low back pain with intradiscal electrothermal therapy

The management of chronic low back pain (CLBP) has proven very challenging in North America, as evidenced by its mounting socioeconomic burden. Choosing among available nonsurgical therapies can be overwhelming for many stakeholders, including patients, health providers, policy makers, and third-party payers. Although all parties share a common goal and wish to use limited health-care resources to support interventions most likely to result in clinically meaningful improvements, there is often uncertainty about the most appropriate intervention for a particular patient. To help understand and evaluate the various commonly used nonsurgical approaches to CLBP, the North American Spine Society has sponsored this special focus issue of The Spine Journal, titled Evidence-Informed Management of Chronic Low Back Pain Without Surgery. Articles in this special focus issue were contributed by leading spine practitioners and researchers, who were invited to summarize the best available evidence for a particular intervention and encouraged to make this information accessible to nonexperts. Each of the articles contains five sections (description, theory, evidence of efficacy, harms, and summary) with common subheadings to facilitate comparison across the 24 different interventions profiled in this special focus issue, blending narrative and systematic review methodology as deemed appropriate by the authors. It is hoped that articles in this special focus issue will be informative and aid in decision making for the many stakeholders evaluating nonsurgical interventions for CLBP.

Percutaneous thermocoagulation intradiscal techniques for discogenic low back pain

STUDY DESIGN

Systematic review.

OBJECTIVE

To systematically review the evidence on the efficacy, effectiveness, and safety of percutaneous thermocoagulation intradiscal techniques for discogenic low back pain.

SUMMARY OF BACKGROUND DATA

The intervertebral disc is thought to be the source of pain in a relevant proportion of cases of low back pain (LBP). Two percutaneous thermocoagulation intradiscal techniques have been described to treat discogenic LBP: percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) and intradiscal electrothermal therapy (IDET).

METHODS

An electronic search was performed in MEDLINE, EMBASE, and the Cochrane Library databases up to 2005, to identify nonrandomized controlled trials and randomized controlled trials (RCTs) on those techniques. All relevant studies were methodologically assessed independently by 3 reviewers. RCTs were assessed following the criteria recommended by the Cochrane Back Review Group. A qualitative synthesis of results was performed.

RESULTS

Six studies were included with a total of 283 patients. Two open, nonrandomized trials (95 patients) showed positive results for IDET compared with rehabilitation and PIRFT. Results from 2 RCTs showed no differences between PIRFT and placebo, and between different PIRFT techniques. Two RCTs compared IDET with placebo. One suggested differences only in pain and in disability, while the best quality RCT showed no differences.

CONCLUSIONS

The available evidence does not support the efficacy or effectiveness of percutaneous thermocoagulation intradiscal techniques for the treatment of discogenic low back pain.

Industrial medicine and acute musculoskeletal rehabilitation. 5. Interventional procedures for work-related lumbar spine conditions

This chapter emphasizes the importance of establishing a differential diagnosis for low back pain (LBP) with and without referred lower-limb pain and outlines potential interventional treatments appropriate for each diagnosis. It is part of the study guide on industrial rehabilitation and acute musculoskeletal rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. The article specifically focuses on the various interventions used to diagnose or treat those conditions commonly seen in patients with work-related LBP or referred pain in the lower limb. Current criterion treatments for lumbar disk pain, including surgical options, are reviewed.

OVERALL ARTICLE OBJECTIVE

To give an overview of the current state of diagnosis and treatment options for low back pain with or without referred leg pain focusing on interventional procedures.

IDET: a critical appraisal of the evidence

Smith and Nephew (Endoscopy division, Andover, MA, USA) have estimated that 60,000 Intra-Discal Electrothermal Therapy (IDET) procedures have been performed world wide up to June 2005. Despite the large number of procedures performed, a critical appraisal of the evidence of efficacy of IDET has not appeared in the literature. This paper reviews the current evidence of clinical efficacy for IDET obtained via a systematic review of the literature. Studies were included if they used at least one of four specified primary outcome measures; pain intensity as assessed by a visual analogue score (VAS), global measurement of overall improvement, back specific functional status such as Oswestry disability Index (ODI) and return to work. Levels of evidence were assigned according to the hierarchy described by the Oxford Centre for Evidence-Based Medicine (www.cebm.net). Papers addressing possible mechanisms of action of IDET were not considered as the focus of the literature review was clinical effectiveness. Eleven prospective cohort studies (level II evidence) were reported on a total of 256 patients with a mean follow-up of 17.1 months (range 12-28 months). The mean improvement in the VAS for back pain was 3.4 points (range 1.4-6.5) and the mean improvement in ODI was 5.2 points (range 4.0-6.4). A total of 379 patients were reported in five retrospective studies (level III evidence). Between 13 and 23% of patients subsequently underwent surgery for low back pain within the study period. Two randomised controlled trials of IDET have been reported in the literature. The first randomised 64 patients (37 to IDET, 27 to Sham). The advantage for IDET patients amounted to 1.3 points on the VAS and seven points on the ODI. The second study randomised 57 subjects (38 to IDET, 19 to Sham) and showed no benefit from IDET over placebo. The evidence for efficacy of IDET remains weak and has not passed the standard of scientific proof.

Meta-Analysis of the Efficacy and Safety of Intradiscal Electrothermal Therapy (IDET)

OBJECTIVE

The objective of this study was to determine the representative outcomes of the intradiscal electrothermal therapy (IDET) procedure in terms of pain relief, reduction of disability, and risk of complications.

DESIGN

Meta-analysis, using a random-effects model. A Medline literature search was conducted using search terms associated with the IDET procedure including IDET, intradiscal electrothermal therapy, intervertebral disk, and annuloplasty.

OUTCOME MEASURES

The outcomes analyzed were the visual analog scale (VAS) assessment of pain, the bodily pain, and physical functioning subscales of the SF-36 health survey, and the Oswestry disability index.

RESULTS

From 1998 to March 2005, 62 peer-reviewed articles were identified regarding the IDET procedure. Forty-five articles were excluded, leaving a total of 17 unique published reports included in this review. The overall mean improvement in pain intensity was 2.9 points as measured by the VAS. The overall mean improvement in physical function was 21.1 points as measured by the SF-36. The overall mean improvement in bodily pain was 18.0 points as measured by the SF-36. The overall mean improvement in disability was 7.0 points as measured by the Oswestry disability index. The overall incidence of complications was 0.8%.

CONCLUSION

Although variation exists in the reported outcomes among the various studies of the IDET procedure, the pooled results of the published studies provide compelling evidence of the relative efficacy and safety of the IDET procedure.

Changes on MRI in lumbar disc protrusions in two patients after intradiscal electrothermal therapy

We examined changes to the protruded lumbar disc after intradiscal electrothermal therapy (IDET) using magnetic resonance imaging (MRI) in two patients with chronic discogenic low back pain who underwent IDET. MRI was performed before and 6 months after the treatments. In the follow-up MRI studies, the protrusions were almost abolished and normalized in both patients. We thus confirmed shrinkage of the protruded disc by IDET on MRI images in two patients.

Intradiscal thermal annuloplasty versus intradiscal radiofrequency ablation for the treatment of discogenic pain: a prospective matched control trial

OBJECTIVE

Two minimally invasive techniques have been used more recently as a possible treatment for painful internal disk disruption (IDD). Intradiscal thermal annuloplasty (IDTA), known as IDET, has already shown promising results in pain reduction and functional restoration. The second technique, radiofrequency posterior annuloplasty (RFA), is used in many interventional pain practices, although studies on the technique's efficacy are lacking. This study compares the effectiveness of those two methods.

DESIGN AND PATIENTS

We matched 42 patients (21 had IDTA and 21 radiofrequency annuloplasty) for age, sex, weight, smoking history, manual labor, and number of intervertebral disks treated. Enrolled patients completed pain disability index (PDI) questionnaires before receiving either IDTA or RFA; at 2 weeks; and 2, 3, 6, 9, and 12 months following either treatment.

RESULTS

From the third to the twelfth month after the procedure, the IDTA group had significantly lower mean pain scores than the RFA group. Visual analog scale (VAS) pain scores decreased from 6.6 +/- 2.0 before to 4.4 +/- 2.4 at 1 year after radiofrequency annuloplasty (P = 0.001), while in the IDTA group the average VAS pain score decreased from 7.4 +/- 1.9 before IDTA to 1.4 +/- 1.9 at 1 year follow-up. Similarly, PDI scores in the IDTA group had a significantly larger improvement than those for patients who received radiofrequency annuloplasty.

CONCLUSIONS

This study shows significant improvement in pain scores and patients' PDI following IDTA but not after RFA of the intervertebral disks. IDTA appears to be more efficacious than RFA based on PDI and VAS scores measured at 1 year following procedure.

Histological and molecular structure characterization of annular collagen after intradiskal electrothermal annuloplasty

The mechanism of pain relief of intradiskal electrothermal annuloplasty (IDET) in the treatment of lumbar diskogenic pain is uncertain. Theories include sealing of annular fissures via collagen denaturation and contraction. Prior studies offer conflicting qualitative data on the ability of IDET to denature collagen. The objective of the present study is to evaluate IDET treatment effect on annular collagen using quantitative data supplied by Fourier-transform infrared imaging spectroscopy. The posterior annulus of disks (n = 3) from an intact human cadaveric spine at room temperature were treated with two different radiothermal catheters using standard intradiskal electrothermal annuloplasty (IDET) heating protocols. Disks were dissected free with catheters in place and fixed in formalin. Channels created by the catheters were marked and catheters were removed. Tissue samples of treated areas adjacent to the channels and internal control areas from the same disk were stained for light microscopy and placed on barium sulfate windows for Fourier transform infrared imaging spectroscopy (FT-IRIS) analysis. Treated areas showed evidence of disruption in the fibrillar organization of annular collagen by light microscopy compared to intact stroma from control areas. Quantitative FT-IRIS analysis compared ratios of wavenumber regions known to be sensitive to collagen denaturation. Mean values for the ratios amide II/1,338 cm(-1) (137.21 +/- 25.84 treated, 76.94 +/- 16.77 control) and 1,640/1,660 cm(-1) (0.98 +/- 0.03 treated, 0.89 +/- 0.03 control) were significantly different between treated and control samples (p < 0.001), indicating a breakdown in collagen integrity. Separate analysis by catheter type suggests that catheter design may impact treatment effect.

Intradiscal Electrothermal Annuloplasty

Low back pain is a common problem, and although the majority of cases of low back pain resolve, a subset of patients will continue to have intractable pain despite appropriate conservative treatments. Intradiscal electrothermal annuloplasty is a minimally invasive spinal procedure that has been proposed to treat provocation discography-proven internal disk disruption syndrome. The early uncontrolled and nonrandomized intradiscal electrothermal annuloplasty literature suggests it may provide some relief in a small proportion of strictly defined patients; however, more recent randomized, placebo-controlled trials have not substantiated these initial findings. This article will review the published literature, indications, contraindications, safety, and efficacy of the intradiscal electrothermal annuloplasty procedure for the treatment of chronic, intractable, axial back pain.