Indian Journal of Pain

REVIEW ARTICLE
Year
: 2021  |  Volume : 35  |  Issue : 2  |  Page : 105--122

Efficacy of radiofrequency lesioning for chronic spinal pain: A systematic review


Sujeet Gautam, Pratibha Singh, Vineetha G Gopal, Anil Agarwal, Sanjay Kumar, Sandeep Khuba, Chetna Shamshery 
 Department of Anaesthesiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

Correspondence Address:
Dr. Sujeet Gautam
Department of Anaesthesiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow - 226 014, Uttar Pradesh
India

Abstract

Introduction: Facet joint pain, discogenic pain, sacroiliac joint (SIJ) pain, and radicular pain are chronic spinal pain conditions, where radiofrequency (RF) lesioning has been used so far with variable results. It is always desired to choose a therapeutic option based on its current evidence. The present systematic review has focused on the efficacy of RF lesioning for chronic spinal pain conditions. Methods: A literature search was done in PubMed from the year 1966 onward. The basic idea of the literature search was to find out studies focusing on RF lesioning for chronic spinal pain. The randomized controlled trials and observational studies focusing on RF lesioning for chronic spinal pain of more than 3 months duration have been included in this review. Results: A total of 286 studies have been identified after literature search and assessed for inclusion in this review. Forty-two of these studies meeting the inclusion criteria have been included for the formulation of evidence; 26 of these studies were of high quality, 14 were of moderate quality, and 2 were of low quality as per Cochrane review criteria score. The level of evidence for RF lesioning of conditions giving rise to nonradicular pain is Level I for continuous RF lesioning of lumbar facet medial branch, for both short- and long-term effectiveness; level II evidence for continuous RF lesioning of cervical facet medial branch, continuous RF or cooled RF lesioning of SIJ and bipolar cooled RF in intradiscal biacuplasty for discogenic pain, for both short- and long-term effectiveness; level III evidence for continuous RF lesioning of thoracic facet medial branch. For radicular pain management, there is Level II evidence for dorsal root ganglion (DRG) pulsed RF lesioning, for both short- and long-term effectiveness. Conclusion: The evidence for RF lesioning of chronic spinal pain is summarized as follows:
  1. Nonradicular pain.
    1. Cervical facet joint pain: Level II evidence for continuous RF lesioning of cervical facet medial branch.
    2. Thoracic facet joint pain: Level III evidence for continuous RF lesioning of thoracic facet medial branch.
    3. Lumbar facet joint pain: Level I evidence for continuous RF lesioning of lumbar facet medial branch.
    4. Sacro-iliac joint pain: Level II for continuous RF or cooled RF lesioning of SIJ.
    5. Discogenic pain: Level II evidence for bipolar cooled RF in intradiscal biacuplasty for discogenic pain.
  2. Radicular Pain: Level II evidence for DRG pulsed RF lesioning for the management of radicular pain.



How to cite this article:
Gautam S, Singh P, Gopal VG, Agarwal A, Kumar S, Khuba S, Shamshery C. Efficacy of radiofrequency lesioning for chronic spinal pain: A systematic review.Indian J Pain 2021;35:105-122


How to cite this URL:
Gautam S, Singh P, Gopal VG, Agarwal A, Kumar S, Khuba S, Shamshery C. Efficacy of radiofrequency lesioning for chronic spinal pain: A systematic review. Indian J Pain [serial online] 2021 [cited 2021 Nov 30 ];35:105-122
Available from: https://www.indianjpain.org/text.asp?2021/35/2/105/325202


Full Text



 Introduction



Chronic spinal pain is one of the most common causes responsible for hospital visits, work loss, and disability among adult patients across the world;[1] it includes chronic neck, upper back, and low back pain. It affects the performance of an individual both at job-related work and daily activities of living at home; this leads to depression, anxiety, and poor quality of life.[2] A high proportion of people in low-income countries like India are involved in physically demanding jobs which may increase the risk of chronic spinal pain.[3] Hence, it is not surprising that 60% of the Indian population suffers from low back pain at some time during their lifetime.[4]

Chronic spinal pain results from multiple factors; any spinal structure which has a nerve supply such as muscle, synovial joints, intervertebral discs, dura mater, and ligaments should cause spinal pain.[1] Diagnostic blocks indicate that intervertebral discs, facet joints, sacroiliac joints (SIJs), and nerve roots are the common sources of spinal pain.[5] The structure responsible for spinal pain is targeted by various therapeutic modalities for achieving long-term pain relief. Radiofrequency (RF) lesioning is very commonly used as a therapeutic modality for the management of chronic spinal pain conditions.

RF lesioning interrupts or alters neural transmission in nociceptive fibers; this offers long-lasting pain relief in many conditions giving rise to chronic spinal pain.[6] Two types of RF lesioning are used in chronic pain conditions. Continuous or thermal RF (CRF) generates a thermal lesion along the nociceptive neural pathway; this interrupts the transmission of nociceptive stimuli, offering pain relief.[6] Pulsed RF (PRF) delivers intermittent pulses of current and does not make a thermal lesion in the surrounding tissue; the dense electrical field generated by PRF along the nerve is proposed to reduce the nociceptive transmission.[7] Cooled RF (CoRF) also uses the same principle as that of CRF, but it consists of an active water-cooling system through the electrode to cool down the probe tip, which keeps the adjacent tissue temperature low, and thus prevents tissue desiccation and helps RF energy to advance farther creating larger size lesions.[8]

RF lesioning has been used in a majority of chronic spinal pain conditions; different mechanisms of action of CRF and PRF have laid down different indications for the two types of RF lesioning. CRF is preferred for sensory nerves or mixed nerves with minimal motor supply; PRF because of its nondestructive nature is preferred for mixed sensory-motor nerves.[9] PRF has also been used in conditions where CRF has shown good results; this is in view of lesser side effects associated with PRF owing to its nonablative nature. However, it is suggested that PRF should not be used as a substitute to CRF in conditions where there is good evidence for the role of CRF.[7],[10]

Facet joint pain, discogenic pain, SIJ pain, and radicular pain are chronic spinal pain conditions, where RF lesioning has been used so far with variable results. It is always desired to choose a therapeutic option based on its current evidence. The present systematic review has focused on the efficacy of RF lesioning for chronic spinal pain conditions; we hope that this review will enable the pain physicians to take a decision based on present evidence.

 Methods



Literature search

A literature search was done in PubMed from the year 1966 onwards. The basic idea of the literature search was to find out studies focusing on RF lesioning for chronic spinal pain; we have included studies for both radicular and nonradicular pain in the present review. The disease conditions included for nonradicular pain were facet joint pain, SIJ pain, and discogenic pain; the disease condition included for radicular pain was disc herniation.

Literature search was done with keywords including chronic spinal pain, chronic low back pain, chronic neck pain, chronic upper back pain, chronic mid back pain, chronic thoracic pain, facet joint pain, SIJ pain, discogenic pain, disc herniation, prolapse intervertebral disc, RF, medial branch RF lesioning, RF lesioning, RF ablation, RF neurotomy, CRF, PRF, biacuplasty, annuloplasty, dorsal root ganglion (DRG), ramus communicans lesioning, internal disc disruption and intradiscal.

Inclusion criteria for the studies

The randomized controlled trials and observational studies focusing on RF lesioning for chronic spinal pain of more than 3 months duration have been included in this review; observational studies have been included for those disease conditions where the number of randomized trials was <5.[11]

Assessment of study quality

The quality of studies meeting the inclusion criteria was assessed based on Cochrane review criteria score [Table 1];[12] the studies were classified into high-quality (score of 8-12), medium-quality (score of 4-7), and low-quality (score <4) [Table 2]. Only high- and medium-quality studies were included in this review; low-quality studies have been included for those disease conditions where the number of randomized trials was <5.[11]{Table 1}{Table 2}

Analysis of evidence

The analysis of evidence was based on best evidence synthesis using five levels of evidence[11],[13] [Table 3].{Table 3}

 Results



The trials focusing on RF lesioning for chronic spinal pain were carefully identified and reviewed for inclusion in this systematic review; the workflow utilized to identify the trials satisfying the inclusion criteria is shown in [Figure 1]. The trials included in the review and their efficacy are outlined in [Table 4],[Table 5],[Table 6],[Table 7],[Table 8],[Table 9],[Table 10],[Table 11],[Table 12],[Table 13],[Table 14],[Table 15].[14] The evidence has been classified into two categories namely nonradicular and radicular pain; RF lesioning for facet joint, SIJ, and discogenic pain has been considered under the nonradicular pain category, while RF lesioning for DRG giving rise to radicular pain has been considered under radicular pain category.{Figure 1}{Table 4}{Table 5}{Table 6}{Table 7}{Table 8}{Table 9}{Table 10}{Table 11}{Table 12}{Table 13}{Table 14}{Table 15}

Nonradicular pain: Facet joint radiofrequency lesioning

Cervical facet radiofrequency lesioning

For this systematic review, 29 studies on the use of RF lesioning in cervical facet joint pain were evaluated, and only 4 of them[14],[15],[16],[17] met the inclusion criteria. The included studies consisted of two high-quality RCT,[14],[17] one prospective observational study[15] of moderate quality, and one nonrandomized comparative study[16] of moderate quality. The description of these studies and their efficacy are outlined in [Table 4] and [Table 10].

There is Level III evidence for both short- and long-term effects for the use of intra-articular PRF for facetogenic pain of the neck, based on the single high-quality RCT[14] included. Regarding the use of CRF in these patients, for both short- and long-term effectiveness, there is Level II evidence based on one high-quality RCT[17] and two nonrandomized medium-quality studies.[15],[16] Considering the variability in the methodology of this limited number of good quality studies, it was difficult to conclude efficiently on the evidence available. Good quality randomized studies in future might help in getting better evidence outcomes.

Thoracic facet radiofrequency lesioning

The evidence for the use of RF lesioning in thoracic facet joint pain is very scarce. 5 studies focussing on the use of RF lesioning in thoracic facet pain were evaluated, and only 3 studies[18],[19],[20] met the inclusion criteria for the review, including 1 RCT[20] of high quality and 2 observational retrospective studies[18],[19] with low quality according to the Cochrane review criteria score [Table 2]. The included studies are summarized in [Table 5].

The results on the efficacy of RF lesioning in this class of pathology are encouraging but very limited [Table 11]. The level of evidence for the use of CRF lesioning of thoracic medial branch Level III for both short-term and long-term effects based on single high-quality RCT.[20] This area needs to be explored more with good quality prospective and randomized trials for getting stronger evidence to conclude efficiently.

Lumbar facet radiofrequency lesioning

A total of 67 studies focusing on lumbar facet RF lesioning were assessed for inclusion in this systematic review. Sixteen studies meeting the inclusion criteria were included in the review;[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34],[35],[36] of these 12 were of high quality[21],[23],[24],[25],[26],[27],[28],[30],[32],[33],[34],[35] and 4 were of moderate quality[22],[29],[31],[36] as per Cochrane review criteria score [Table 2]. The study characteristics are summarized in [Table 6].

The evidence for the efficacy of thermal RF lesioning in the treatment of lumbar facet joint mediated pain is quite promising [Table 12]. There is Level I evidence for short-term effectiveness (<6 months) for thermal RF lesioning based on 10 high-quality RCTs[21],[23],[24],[25],[27],[28],[30],[32],[33],[34] and 3 moderate quality RCTs.[22],[29],[31] Similarly, there is Level I evidence for long-term effectiveness of thermal RF lesioning (≥6 months), which was derived from 8 high-quality studies[21],[24],[25],[27],[28],[32],[33],[34] and 1 moderate quality study[22] showing sustained improvement in pain and function. However, Tillberg et al.[26] did not found any significant benefit of CRF lesioning of the medial branch over the sham group.

There is wide variability in the selection of patients, type of RF used, and target for RF lesioning, employed in different studies. While most of the studies have targeted the medial branch of the dorsal ramus, one high-quality RCT showed good results by targeting the lumbar facet joint capsule[25] and another high-quality RCT showed promising outcomes through intraarticular RF.[24] Majority of the clinical trials have utilized the pillar view technique for the thermal RF ablation of the medial branch.[21],[23],[27],[29],[30],[31],[32],[33],[34],[35],[36] The literature is vast for the role of CRF in facetogenic low back pain, but good quality studies for evidence of cooled or pulsed RF are limited. In our review, we found one high-quality RCT that reported cooled RF was as effective as thermal RF,[21] one high-quality RCT that concluded intraarticular PRF to be as effective as intraarticular steroids[24] and 1 moderate quality RCT that showed PRF is not as effective as CRF in facetogenic low back pain.[32]

Nonradicular pain: Sacro-iliac joint radiofrequency lesioning

Fifty-seven studies focussing on RF denervation for SIJ pain were evaluated. 7 RCTs[37],[38],[39],[40],[41],[42],[43] meeting the inclusion criteria were included in this review; 5 of them[37],[39],[40],[42],[43] were of high quality and 2 studies had a moderate quality[38],[39],[40],[41] as per Cochrane review criteria score [Table 2]. The included studies and their efficacy have been outlined in [Table 7] and 13 respectively.

CRF, PRF, and CoRF had all been used for the management of SIJ pain in the presently available trials. There is high degree of nonuniformity in the RF modality, lesioning parameters, and target sites used in the limited number of trials available for the management of SIJ pain via RF lesioning; hence, it was difficult to suggest a clear level of evidence for each type of RF used in the management of SIJ pain. There is Level II evidence available for both short- and long-term efficacy of CRF (2 moderate quality RCTs and one high-quality RCT)[38],[41],[42],[43] and cooled RF (2 high-quality RCTs)[40],[42] in the management of SIJ pain; one high-quality RCT[37] also supported the role of PRF lesioning for SIJ pain.

Nonradicular pain: Radiofrequency lesioning for discogenic pain

Seventy-six studies regarding the use of RF lesioning in discogenic pain were assessed for this systematic review, and 7 studies[44],[45],[46],[47],[48],[49],[50] meeting the inclusion criteria have been included in the review. Among the included studies, all were RCTs of high[46],[47],[50] to moderate quality[44],[45],[48],[49] as per Cochrane review criteria score [Table 2]. The included studies and their efficacy are tabulated in [Table 8] and [Table 14].

The role of bipolar CoRF in intradiscal biacuplasty (IDB) for discogenic pain has been found to be efficacious for both short (<6 months) and long term (6 months) by one high quality[46] and one moderate quality[44] RCT; hence, as per the review a Level II evidence for the use of bipolar CoRF in IDB for discogenic pain. Among other RF modalities for discogenic pain a role of CoRF lesioning of ramus communicans nerve for disc-related pain has been suggested by a single moderate-quality RCT,[48] with short term efficacy (4 months). The role of intradiscal CRF lesioning for discogenic pain has been supported by one moderate-quality RCT[49] and declined by a high-quality RCT;[50] the role of intradiscal electrothermal therapy (IDET) in discogenic pain has been negated by Freeman et al. in a high-quality RCT.[47]

There is a major diversity in the type of current and lesion parameters of the intradiscal RF lesioning used in discogenic pain. The role of a definitive RF lesioning modality is yet to be established.

Radicular pain: dorsal root ganglion radiofrequency lesioning

A total of 51 studies focusing on RF lesioning of DRG for radicular pain were assessed for inclusion in this systematic review. 6 studies meeting the inclusion criteria were included in the review;[51],[52],[53],[54],[55],[56] out of these 4 were of high quality[50],[54],[55],[56] and 2 were of moderate quality[52],[53] as per Cochrane review criteria score [Table 2]. The study characteristics are summarized in [Table 9].

The evidence for the efficacy of RF lesioning of DRG, in the treatment of spinal radicular pain, is encouraging [Table 15]. There is Level II evidence for short-term effectiveness (<6 months) of DRG PRF lesioning, based on 2 high-quality RCTs[51],[54] and 2 moderate quality RCTs.[52],[53] Similarly, there is Level II evidence for long-term effectiveness of DRG RF lesioning (≥6 months), derived from one high-quality study[51] and one moderate quality study[52] that showed persistent improvements in pain and function.

The literature is more convincing for the role of PRF lesioning of DRG in comparison to CRF, in the management of radicular pain. There are four moderate-to high-quality RCTs[51],[52],[53],[54] substantiating the effectiveness of PRF, two of which concluded that the benefits were maintained even in long term.[51],[52] However, out of two high-quality RCTs for CRF lesioning of DRG, one has suggested only short-term benefits in improving radicular pain[56] whereas the other has established it as ineffective in both short term and long term.[55]

Another important fact regarding DRG RF lesioning for radicular lesioning was better results for lumbosacral radicular pain in comparison to cervical radicular pain; DRG RF lesioning has contributed to long-term benefits for lumbar radicular pain[51],[52] in comparison to short-term benefits for cervical radicular pain.[54],[56] Hence, good quality randomized studies are warranted in future to determine the efficacy of DRG RF, especially for cervical radicular pain.

 Discussion



The present systematic review has analyzed the literature related to RF lesioning for chronic spinal pain conditions. The first step in the management of any chronic spinal pain condition is the identification of a cause giving rise to chronic spinal pain; usually, this is done in the form of a local anesthetic diagnostic block. The next step is to utilize therapeutic options offering long-term pain relief; RF lesioning is one such modality which is very commonly used in the field of chronic pain to offer long-term benefits. RF lesioning offers variable efficacy in different chronic pain conditions. Hence, it is wise to choose RF lesioning as a therapeutic option for any chronic spinal pain condition based on the evidence available in the current literature; this review is an attempt in this direction.

The efficacy of RF lesioning depends on a number of variables including type of RF; lesion parameters temperature, duration, and voltage used for lesioning; needle and active tip dimensions; single or dual diagnostic blocks before RF lesioning; target site used for lesioning and needle orientation with respect to the nerve. Different parameters have been used in different studies based on the availability of RF generator, operator expertise, and preference; hence, it is very difficult to formulate evidence for a therapeutic modality like RF, with so many variables capable of affecting the treatment efficacy.

A total of 286 studies have been identified after literature search and assessed for inclusion in this review. Forty-two of these studies meeting the inclusion criteria have been included for the formulation of evidence; 26 of these studies were of high quality, 14 were of moderate quality and 2 were of low quality as per Cochrane review criteria score [Table 2]. Two low-quality observational retrospective studies[18],[19] were included for thoracic facet RF lesioning, where we could find only one RCT available in the literature. 22 of the 42 studies included in this review are related to facet joint pain [Table 4],[Table 5],[Table 6], 7 studies for SIJ pain [Table 7], 7 studies for discogenic pain [Table 8], and 6 studies for DRG lesioning [Table 9].

The level of evidence for RF lesioning of conditions giving rise to nonradicular pain is Level I for CRF lesioning of lumbar facet medial branch, for both short- and long-term effectiveness; Level II evidence for CRF lesioning of cervical facet medial branch, CRF or CoRF lesioning of SIJ and bipolar CoRF in intradiscal biacuplasty for discogenic pain, for both short- and long-term effectiveness; Level III evidence for CRF lesioning of thoracic facet medial branch. For radicular pain management, there is Level II evidence for DRG PRF lesioning, for both short- and long-term effectiveness [Table 16].{Table 16}

Limitations of the review

First, there is wide heterogenicity in the studies included in the review, with respect to patient selection, the technique of RF lesioning employed, and outcome measures studied. Secondly, we have included RCTs with a minimum follow-up period of 3 months; this kind of study selection was done due to the paucity of good quality RF lesioning studies in many chronic spinal pain conditions. Hence, systematic reviews in future, can arrive in a better conclusion regarding the efficacy of RF, if more RCTs with a large sample size and long follow-up period are available. Thirdly, we have done literature search for the role of RF lesioning for various conditions; however, in certain conditions more than one RF type has been used in different trials (for example SIJ pain, discogenic pain, and DRG lesioning). A literature search focusing on specific RF types will result in the inclusion of more observational trials owing to the lack of adequate RCTs focusing on specific RF types; this carries a possibility of affecting the overall evidence.

 Conclusion



The evidence for RF lesioning of chronic spinal pain is summarized as follows:

Nonradicular pain:

Cervical facet joint pain: Level II evidence for CRF lesioning of cervical facet medial branch (short- and long-term effectiveness); the CRF lesioning parameters advised for cervical facet medial branch are 80°–85° C for 90 s.[15],[16],[17]Thoracic facet joint pain: Level III evidence for CRF lesioning of thoracic facet medial branch (short- and long-term effectiveness); the CRF lesioning parameters advised for thoracic facet medial branch are 90°C for 90 s.[20]Lumbar facet joint pain: Level I evidence for CRF lesioning of lumbar facet medial branch (short-and long-term effectiveness); the CRF lesioning parameters advised for lumbar facet medial branch are 80°C for 90 s.[21],[22],[25],[27],[28],[29],[30],[31]Sacro-iliac joint pain: Level II for CRF or CoRF lesioning of SIJ (short- and long-term effectiveness); RF lesioning parameters advised are 80°-90°C for 90–180 s for CRF[41],[43] and 60°C for 150 s for CoRF.[40],[42],[43]Discogenic pain: Level II evidence for bipolar CoRF in intradiscal biacuplasty for discogenic pain (short-and long-term effectiveness).[44],[45],[46]

Radicular pain: Level II evidence for DRG PRF lesioning for the management of radicular pain; the PRF lesioning parameters used for DRG medial branch for the management of radicular pain are 42°C for 120–180 s.[51],[52],[53],[54]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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