Psychological predictors of substantial pain reduction after minimally invasive radiofrequency and injection treatments for chronic low back pain.

OBJECTIVE: In this post hoc observational study, we investigated psychological predictors of outcome after radiofrequency and injection treatments, commonly performed in the management of chronic low back pain (CLBP). DESIGN & SETTING: Data, comprising 161 patients (29 eventually lost to follow-up), were obtained from two randomized controlled trials on efficacy of radiofrequency treatment for back pain and sciatica. Subsequently patients were additionally treated in an open prospective follow-up period. Although all groups presented a significant visual analog scale reduction after 3 and 12 months, no additional pain relief after radiofrequency compared with injection treatment was found. Both trial populations showed sufficient similarities. A principal component (factor) analysis was performed on baseline psychometric tests, SF-36, and physical activity variables. We constructed five clinically relevant psychological profiles: "psychologically negative,""adaptive manager,""rigid qualities,""supporting partner," and "strong ego." These were examined as possible predictors of significant pain relief using logistic regression analysis. RESULTS: The "psychologically negative" dimension showed a negative and the "adaptive manager" dimension a positive prognostic effect on outcome. CONCLUSIONS: Minimally invasive treatment for CLBP leads to significant pain reduction, including potential placebo effects. However, psychologically vulnerable patients, characterized by, among others, reduced life control, disturbed mood, negative self-efficacy, catastrophizing, high anxiety levels, inadequacy, and poor mental health, tend not to respond to this treatment. Patients characterized by a.o. reduced pain and interference levels, positive expectations, and reasonable physical and social functioning, react more favorably. From both a clinical and a financial perspective, psychosocial evaluation and selection of patients seems appropriate, before applying minimally invasive procedures for CLBP.

Radiofrequency denervation of lumbar facet joints in the treatment of chronic low back pain: a randomized, double-blind, sham lesion-controlled trial.

OBJECTIVES: Radiofrequency facet joint denervation procedures have been common practice for 2 decades in treatment of chronic low back pain. We designed this multicenter, randomized, double-blind, sham treatment controlled trial to determine the efficacy of radiofrequency facet joint denervation, as it is routinely performed. METHODS: Inclusion criteria were low back pain, duration more than 6 months, and >or=50% Visual Analog Scale (VAS) reduction on diagnostic block. Exclusion criteria were prior radiofrequency treatment, radicular syndrome, coagulopathies, specific allergies, cancer, and pregnancy. A total of 81 out of 462 patients were randomized to undergo radiofrequency facet joint denervation or sham treatment. The first evaluation was carried out 3 months after treatment. Primary outcome was determined with a combined outcome measure comprising VAS, physical activities, and analgesic intake, from a twice-weekly recorded diary. Secondary outcome measures were the separate diary parameters, global perceived effect (complete relief, >50% relief, no effect, pain increase), and SF-36 Quality of Life Questionnaire. RESULTS: There were no dropouts before the first evaluation. The combined outcome measure showed no differences between radio- frequency facet joint denervation (n=40; success 27.5%) and sham (n=41; success 29.3%) (P=0.86). The VAS in both groups improved (P<0.001). Global perceived effect improved after radiofrequency facet joint denervation (P<0.05). The other secondary outcome parameters showed no significant differences. Relevant costs were evaluated. DISCUSSION: The combined outcome measure and VAS showed no difference between radiofrequency and sham, though in both groups, significant VAS improvement occurred. The global perceived effect was in favor of radiofrequency. In selected patients, radiofrequency facet joint denervation appears to be more effective than sham treatment.

Radiofrequency lumbar facet denervation: a comparative study of the reproducibility of lesion size after 2 current radiofrequency techniques.

BACKGROUND AND OBJECTIVES: Radiofrequency facet denervation procedures are widely used for the treatment of chronic low-back pain. Currently, both temperature-controlled and voltage-controlled techniques are used. In this combined in vivo and in vitro study, the electrophysiologic consequences and the effects on lesion size of these techniques were determined. METHODS: Thirty-three patients were randomly assigned to receive a lumbar radiofrequency facet denervation by using either temperature-controlled (80 degrees C, 60 seconds) or voltage-controlled (20 V, 60 s) mode. Electrophysiologic parameters in both groups during radiofrequency lesioning were registered. Observed differences between electrodes were quantified and interpreted, using lesion-size data from egg-white experiments. RESULTS: Seventeen patients in the temperature group were treated with a total of 55 radiofrequency lesions, all considered technically adequate. In the voltage-controlled group, 16 patients received 63 lesions. Of these, 44 (69.8%) procedures were found to be technically inadequate. Voltage-controlled radiofrequency lesioning resulted in uncontrollable fluctuations of temperature, with resultant uncontrollable variations in lesion size. Temperature-controlled mode created reproducible lesion sizes. CONCLUSIONS: There is no consistent relation between voltage and the temperature obtained during radiofrequency lumbar facet denervation. Temperature-controlled radiofrequency lesioning is preferred to create reproducible lesion sizes.

Do minimally invasive procedures have a place in the treatment of chronic low back pain?

Chronic low back pain is the leading cause of disability in the industrialized world. Medical and surgical treatments remain costly despite limited efficacy. The field of 'interventional pain' has grown enormously and evidence-based practice guidelines are systematically developed. In this article, the vast, complex and contradictory literature regarding the treatment of chronic low back pain is reviewed. Interventional pain literature suggests that there is moderate evidence (small randomized, nonrandomized, single group or matched-case controlled studies) for medial branch neurotomy and limited evidence (nonexperimental one or more center studies) for intradiscal treatments in mechanical low back pain. There is moderate evidence for the use of transforaminal epidural steroid injections, lumbar percutaneous adhesiolysis and spinal endoscopy for painful lumbar radiculopathy, and spinal cord stimulation and intrathecal pumps mostly after spinal surgery. In reality, there is no gold standard for the treatment of chronic low back pain, but these results appear promising.

Radiofrequency lesioning of dorsal root ganglia for chronic lumbosacral radicular pain: a randomised, double-blind, controlled trial.

BACKGROUND: Results of observational studies have shown pain reduction with percutaneous radiofrequency lesioning of dorsal root ganglia for lumbosacral radicular pain, but there are few randomised controlled trials. We aimed to assess the efficacy of radiofrequency lesioning of dorsal root ganglia for lumbosacral radicular pain. METHODS: We screened 1001 patients, who were mostly referred by their family doctor, in four hospitals for a double-blind randomised trial. 83 patients met inclusion criteria and thus were randomly assigned to receive a radiofrequency lesion or control treatment of the involved dorsal root ganglion. Control treatment was done in the same way as radiofrequency lesioning, but without radiofrequency current. Preoperatively and during 3-month follow-up, patients reported visual analogue leg-pain and back-pain scores, physical impairment, and use of analgesics in a diary. Primary outcome was success or failure of treatment, defined by a multidimensional decision rule, which included median outcome variables from the diary. Post-hoc analysis for possible covariate interference with outcome variables was done. Primary outcome data were analysed on an intention-to-treat basis. FINDINGS: 45 patients were assigned radiofrequency lesioning and 38 control treatment. Three patients dropped out before 3 months. After 3 months, seven (16%) of 44 patients treated with radiofrequency lesioning and nine (25%) of 36 in the control group had successful treatment (difference -9.1% [95% CI -33.0 to 12.0], p=0.43). No differences between groups in side-effects were seen. INTERPRETATION: Lumbosacral radiofrequency lesioning of dorsal root ganglia failed to show advantage over control treatment with local anaesthetics. Thus, its use as routine treatment in lumbosacral radicular pain should not be advocated.

The efficacy of radiofrequency lesioning of the cervical spinal dorsal root ganglion in a double blinded randomized study: no difference between 40 degrees C and 67 degrees C treatments.

The efficacy of radiofrequency lesion treatment of the cervical dorsal root ganglion (RF-DRG) in cervicobrachialgia was investigated in 61 patients by a randomized prospective double blinded study. Before lesion treatment the putative pain provoking spinal root was identified by diagnostic blocks with a local anesthetic agent. One group of patients (n = 32, group I) was treated with a radiofrequency lesion of 67 degrees C and in a control group (n = 29, group II) a temperature of 40 degrees C was applied. Three months after treatment a significant reduction in VAS scores was demonstrated in both groups. The outcome of the treatments was identical (VAS reduction: group I, 1.7; group II, 1.9; P = 0.001). In group I a VAS reduction of 3 or more occurred in 11/31 (34%) and in group II in 11/29 (38%) of patients. A VAS reduction of 2 or more occurred in group I in 15/31 (47%) and in group II in 15/29 (51%) of patients. This study suggests that treatment with 40 degrees C radiofrequency application of the dorsal root ganglion is equally effective as treatment at 67 degrees C. Further appraisal of this treatment is required.