Percutaneous radiofrequency rhizotomy of lumbar spinal facets: the results of 46 cases

Intra-dural intercommunications between dorsal roots of adjacent spinal nerves and their clinical significance

PURPOSE

The dorsal roots of adjacent spinal nerves are known to communicate with each other through rami communicantes. These intercommunications can cause deviations in the normal dermatomal organization which leads to errors during clinical decision-making. The objective of the study was to augment the existing knowledge of these communications which shall help minimize the diagnostic and therapeutic errors.

METHODS

The present study examined thirty cadaveric spinal cord specimens to document the data of intra-dural, intercommunications between dorsal roots of adjacent spinal nerves.

RESULTS

All the regions of the spinal cord exhibited the presence of intercommunications with variable frequency. The intercommunications were categorized into a total of nine groups based on their patterns. The levels of spinal cord exhibiting higher and lower frequencies of intercommunications were identified.

CONCLUSION

This information will be useful during the clinical evaluation of patients with spinal cord pathologies or radiculopathies. The outcomes of rhizotomy can also be improved with knowledge of intercommunications.

A randomized, double-blind, prospective study comparing the efficacy of continuous versus pulsed radiofrequency in the treatment of lumbar facet syndrome

STUDY OBJECTIVES

To compare the efficacy of continuous radiofrequency (CRF) thermocoagulation with pulsed radiofrequency (PRF) in the treatment of lumbar facet syndrome.

DESIGN

Prospective, randomized, double-blinded study.

SETTING

Ambulatory pain clinic at a level-I trauma center and teaching institution.

PATIENTS

50 ASA physical status I, II, and III patients, at least 18 years of age, scheduled to undergo CRF or PRF for lumbar back pain.

INTERVENTIONS

Target facet joints were identified with oblique radiographic views. Continuous radiofrequency thermocoagulation was delivered at 80 degrees C for 75 seconds, while PRF was delivered at 42 degrees C with a pulse duration of 20 ms and pulse rate of two Hz for 120 seconds.

MEASUREMENTS

Visual analog scale (VAS) pain assessment and Oswestry Low Back Pain and Disability Questionnaire (OSW) were administered at baseline and then at three months. Comparisons between groups and within groups were made of the relative percentage improvement in VAS and OSW scores.

MAIN RESULTS

No significant differences in the relative percentage improvement were noted between groups in either VAS (P = 0.46) or OSW scores (P = 0.35). Within the PRF group, comparisons of the relative change over time for both VAS (P = 0.21) and OSW scores (P = 0.61) were not significant. However, within the CRF group, VAS (P = 0.02) and OSW scores (P = 0.03) showed significant improvement.

CONCLUSIONS

Although there was no significant difference between CRF and PRF therapy in long-term outcome in the treatment of lumbar facet syndrome, there was a greater improvement over time noted within the CRF group.

A comparison of conventional and pulsed radiofrequency denervation in the treatment of chronic facet joint pain

OBJECTIVES

The goal of this study was to compare the effects of conventional radiofrequency (CRF) and pulsed RF (PRF) denervation to medial branches of dorsal rami in the treatment of facet joint pain.

METHODS

The patients greater than 17-year old, with continuous low back pain with or without radiating pain with focal tenderness over the facet joints, pain on hyperextension, absence of neurologic defect, unresponsiveness to conservative treatment, no radicular syndrome, and no indication for low back surgery were included in the study. Local anesthetic was applied in the control group (n=20), whereas 80 degrees C CRF were applied in the CRF (n=20) and 2 Hz PRF were applied in the PRF group (n=20). Pain relief was evaluated by visual analog scale (VAS) and Oswestry Disability Index (ODI) at preprocedure, at procedure, at 6 months and 1 year after the procedure. Reduction in analgesic usage, patients' satisfaction, and complications were assessed.

RESULTS

Mean preprocedural VAS and ODI scores were higher than postprocedural scores in all groups. Both VAS and ODI scores of PRF and CRF groups were lower than the score of the control group at the postprocedural evaluation. Although decrease the pain score was maintained in the CRF group at 6 months and 1-year period, this decrease discontinued in the PRF group at the follow-up periods. The number of patients not using analgesics and patient satisfaction were highest in CRF group.

DISCUSSION

PRF and CRF are effective and safe alternatives in the treatment of facet joint pain but PRF is not as long lasting as CRF.

Alternative denervation using laser irradiation in lumbar facet syndrome

BACKGROUND AND OBJECTIVE

Facet syndrome is persistent low back pain that might be treated with some surgical interventions. The target of surgical techniques is the transverse process bases where the medial nerve branches innervated the facet. However, highly variable success rates have been demonstrated in different series.

STUDY DESIGN/MATERIALS AND METHODS

We carried out laser denervation to the dorsal surface of the facet capsule, where it is richly innervated with medial nerve branches.

RESULTS

One year after laser denervation, 17 patients (81%) experienced complete or greater than 70% pain reduction in all 21 patients. Among the six patients who had previously undergone spinal surgery, two (33.3%) experienced successful pain relief. Overall, in four patients (19%), the response to laser denervation at 1-year follow-ups was not successful.

CONCLUSION

The dorsal surface of the facet capsule might be a more preferable target for facet denervation.

Pulsed radiofrequency neurotomy: advances in pain medicine

In the past three decades, radiofrequency neurotomy (RFN) has been established as a safe and effective treatment for facet and sacroiliac arthropathy. However, early reports of deafferentation pain syndromes and motor deficit with the application of radiofrequency lesions to other neural structures effectively halted further development of this technology for other applications until recent years. Pulsed radiofrequency neurotomy (PRFN) represents the most recent advance in radiofrequency technology in clinical practice. PRFN allows for application of radiofrequency current at markedly lower tissue temperatures, thereby minimizing the risk of adverse events. The initial clinical data on PRFN demonstrate response rates similar to conventional high temperature RFN lesions for facet and sacroiliac arthropathy and a host of other chronic pain disorders.

Radiofrequency denervation for neck and back pain: a systematic review within the framework of the cochrane collaboration back review group

STUDY DESIGN

Systematic review.

OBJECTIVE

To assess the effectiveness of radiofrequency denervation for the treatment of musculoskeletal pain disorders.

SUMMARY OF BACKGROUND DATA

There is a lack of effective treatment for chronic zygapophysial joint pain and discogenic pain. Radiofrequency denervation appears to be an emerging technology, with substantial variation in its use.

METHODS

Original articles for this review were identified by electronically searching MEDLINE, PsycLIT, EMBASE, and the Cochrane Library to February 2002, hand-screening references, and consulting experts in the field. Two reviewers selected the randomized controlled trials that met the inclusion criteria, extracted the data, and assessed the main results and methodologic quality of the selected trials. Finally, qualitative analysis was conducted to evaluate the level of scientific evidence.

RESULTS

Of seven relevant randomized controlled trials, six were considered to be high quality. The selected trials included 275 randomized patients, 141 of whom received active treatment. One study examined cervical zygapophysial joint pain; two, cervicobrachial pain; three, lumbar zygapophysial joint pain; and one, discogenic low back pain. The sample sizes were small, follow-up times short, and there were deficiencies noted in patient selection, outcome assessments, and statistical analyses.

CONCLUSIONS

There is limited evidence that radiofrequency denervation offers short-term relief for chronic neck pain of zygapophysial joint origin and for chronic cervicobrachial pain, and conflicting evidence for its effectiveness for lumbar zygapophysial joint pain. There is limited evidence suggesting that intradiscal radiofrequency may not be effective in relieving discogenic low back pain. Further high-quality randomized controlled trials are needed, with larger patient samples and data on long-term effects, for which current evidence is inconclusive.

A critical review of the evidence for the use of zygapophysial injections and radiofrequency denervation in the treatment of low back pain

BACKGROUND CONTEXT

Lumbar zygapophysial joints are currently believed to be a cause of axial low back pain. Once this diagnosis is made, decisions about when to institute a particular intervention and which treatment to offer is regionally and specialty dependent.

PURPOSE

To perform a critical review of prior published studies assessing the use of interventional treatment options for the treatment of lumbar zygapophysial joint syndrome.

STUDY DESIGN

Evidence-based medicine analysis of current literature.

METHODS

A database search of Medline (PubMed, Ovid and MDConsult), Embase and the Cochrane database was conducted. The keywords used were low back pain, lumbar zygapophysial joint, lumbar facet joint, radiofrequency denervation, medial branch block, and intraarticular injection. After identifying all relevant literature, each article was reviewed. Data from the following categories were compiled: inclusion criteria, randomization of subjects, total number of subjects involved at enrollment and at final analysis. statistical analysis used, intervention performed, outcome measures, follow-up intervals and results. Guidelines described by the Agency for Health Care Policy and Research were then applied to these data.

RESULTS

This review determined that the evidence for the treatment of lumbar zygapophysial joint syndrome with intraarticular injections should be rated as level III (moderate) to IV (limited) evidence, whereas that for radiofrequency denervation is at a level III.

CONCLUSIONS

Current studies fail to give more than sparse evidence to support the use of interventional techniques in the treatment of lumbar zygapophysial joint-mediated low back pain. This review emphasizes the need for larger, prospective, randomized controlled trials with uniform inclusion and exclusion criteria, standardized treatment, uniform outcome measures and an adequate duration of follow-up period so that definitive recommendations for the treatment of lumbar zygapophysial joint-mediated pain can be made.

Radiofrequency denervation for neck and back pain. A systematic review of randomized controlled trials

BACKGROUND

The diagnosis of cervical or lumbar zygapophyseal joint pain can only be made by using local anesthesia to block the nerves supplying the painful joint. There is a lack of effective treatment for chronic zygapophyseal joint pain or discogenic pain. Radiofrequency denervation appears to be an emerging technology, with substantial variation in its use between countries.

OBJECTIVES

To assess the effectiveness of radiofrequency denervation for the treatment of musculoskeletal pain disorders.

SEARCH STRATEGY

We searched MEDLINE, PsycLIT, and EMBASE from start to February 2002, plus the Cochrane Library 2002, Issue 2. The references of identified articles were checked and three experts in the field of radiofrequency treatment were consulted to identify studies we might have missed.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of radiofrequency denervation for musculoskeletal pain disorders, with no language or date restrictions.

DATA COLLECTION AND ANALYSIS

Two reviewers selected RCTs that met predefined inclusion criteria, extracted the data, and assessed the main results and methodological quality of the selected trials, using standardized forms. Qualitative analysis was conducted to evaluate the level of scientific evidence.

MAIN RESULTS

We found only nine articles, reporting on seven relevant RCTs. Six of the seven were considered to be high-quality. The selected trials included 275 randomized patients, 141 of whom received active treatment. One study examined cervical zygapophyseal joint pain, two cervicobrachial pain, three lumbar zygapophyseal joint pain, and one discogenic low-back pain. The study sample sizes were small, follow-up times short, and there were some deficiencies in patient selection, outcome assessments, and statistical analyses. The level of scientific evidence for the short-term effectiveness of radiofrequency denervation was limited for cervical zygapophyseal joint and cervicobrachial pain, and conflicting for lumbar zygapophyseal joint pain. There was limited evidence suggesting that intradiscal radiofrequency thermocoagulation was not effective for discogenic low-back pain.

REVIEWER'S CONCLUSIONS

The selected trials provide limited evidence that radiofrequency denervation offers short-term relief for chronic neck pain of zygapophyseal joint origin and for chronic cervicobrachial pain; conflicting evidence on the short-term effect of radiofrequency lesioning on pain and disability in chronic low-back pain of zygapophyseal joint origin; and limited evidence that intradiscal radiofrequency thermocoagulation is not effective for chronic discogenic low-back pain. There is a need for further high-quality RCTs with larger patient samples and data on long-term effects, for which current evidence is inconclusive. Furthermore, RCTs are needed in non-spinal indications where radiofrequency denervation is currently used without any scientific evidence.

Kryorhizotomy: an alternative technique for lumbar medial branch rhizotomy in lumbar facet syndrome

OBJECT

The authors conducted a prospective study to investigate the efficacy of kryorhizotomy, an alternative procedure for lumbar medial branch neurotomy, in the treatment of lumbar facet syndrome (LFS).

METHOD

Fifty patients with chronic low-back pain, in whom pain was relieved by controlled diagnostic medial branch blocks of the lumbar zygapophyseal (facet) joints, underwent lumbar medial branch kryorhizotomy. Outcome was evaluated using the Visual Analog Pain Scales and assessment of work capacity. All outcome measures were repeated at 6 weeks, 6 months, and 1 year after surgery. At 1-year follow-up examination, 31 (62%) of 50 patients experienced a good response to lumbar facet kryorhizotomy. Good results with pain relief of 50% or more were obtained in 85% of patients without previous spinal surgery but only in 46% who had undergone previous spinal surgery. This difference was statistically significant. In five patients (16%) in whom a good initial benefit was observed but who experienced increased pain within 6 weeks after kryorhizotomy, the beneficial result was regained after an early repeated procedure. There were no side effects. Overall, 19 (38%) of 50 procedures were not considered successful. In six of these 19 cases a rigid stabilization of the involved segment provided permanent pain relief.

CONCLUSIONS

Based on this study, patients with LFS who have not undergone previous spinal surgery benefit significantly from percutaneous lumbar kryorhizotomy. Kryorhizotomy, which has virtually no risk, seems to be a valuable alternative technique to lumbar medial branch neurotomy.

Long-term effects of nerve blocks in chronic pain

Regional blockade techniques have been of crucial importance for decades in chronic pain therapy, but in recent years some developments have made a new definition of the status of invasive procedures necessary. The realization of chronic pain as a multifactorial process led to the establishment of an interdisciplinary approach to pain therapy, leaving blockades as only one step in a multimodal therapy. The mainstay of local anaesthetic blocks now is diagnostic and prognostic, but correct interpretation of the results is limited by different factors, and controlled studies on the diagnostic value of local anaesthetic blockade are lacking. In cancer pain, invasive procedures are necessary in only a few cases. Some neuroablative techniques can offer long-term pain reduction. In non-cancer pain, neurodestructive procedures should be reserved for some special indications (e.g. lumbar sympathetic neurolytic blocks in ischaemic diseases). In a great number of chronic pain conditions the sympathetic nervous system is involved or even has a central status. In the acute stage of these diseases sympathetic blockades can be the therapy of choice. There is no disease in which different invasive procedures are performed so frequently and so uncritically as in chronic low back pain. Up to now, however, all controlled studies of invasive procedures only demonstrated short-term effects and failed to prove long-term efficacy. Therefore any invasive technique should only be performed in well-selected patients over a defined period and with a limited number of blockades.