Anna Luisa Paiva Romano Bernardes,Renato Ferraz Correa,Larissa Alexsandra da Silva Neto Trajano,Iberico Alves Fontes
Lumbar Facet Syndrome and the Use of Radiofrequency Ablation Technique as an Alternative Therapy: A Systematic Review
zygapophyseal joint,low back pain,radiofrequency therapy,lumbar vertebrae,articulação zigapofisária,dor lombar,terapia por radiofrequência,vértebras lombares
Lumbar facet syndrome stands out as a significant cause for the increasing prevalence of back pain complaints. Alternatives such as radiofrequency (RF) ablation may be a therapeutic option to relieve the chronic pain associated with this condition. It is critical to analyze the effectiveness of lumbar facet syndrome treatment using the traditional RF ablation technique and the relief generated by it in chronic low back pain (CLBP). This study is a systematic review using the following inclusion criteria: title, observational studies, clinical trials, controlled clinical trials, clinical studies, and publications over the last 17 years (from 2005 to 2022). The exclusion criteria included papers addressing other themes and review articles. The databases used for data collection included the Medical Literature Analysis and Retrieval System Online (Medline), PubMed, Scientific Electronic Library Online (SciELO), Lilacs, and Biblioteca Virtual em Saúde (Virtual Health Library in Portuguese). The query used the following terms: facet, pain, lumbar, and radiofrequency. The application of these filters yielded 142 studies, and 12 were included in this review. Most studies indicated that the traditional RF ablation technique was beneficial in relieving CLBP refractory to conservative treatment.
Lumbar Facet Syndrome and the Use of Radiofrequency Ablation Technique as an Alternative Therapy: A Systematic Review

Lumbar facet syndrome stands out as a significant cause for the increasing prevalence of back pain complaints. Alternatives such as radiofrequency (RF) ablation may be a therapeutic option to relieve the chronic pain associated with this condition. It is critical to analyze the effectiveness of lumbar facet syndrome treatment using the traditional RF ablation technique and the relief generated by it in chronic low back pain (CLBP). This study is a systematic review using the following inclusion criteria: title, observational studies, clinical trials, controlled clinical trials, clinical studies, and publications over the last 17 years (from 2005 to 2022). The exclusion criteria included papers addressing other themes and review articles. The databases used for data collection included the Medical Literature Analysis and Retrieval System Online (Medline), PubMed, Scientific Electronic Library Online (SciELO), Lilacs, and Biblioteca Virtual em Saúde (Virtual Health Library in Portuguese). The query used the following terms: facet, pain, lumbar, and radiofrequency. The application of these filters yielded 142 studies, and 12 were included in this review. Most studies indicated that the traditional RF ablation technique was beneficial in relieving CLBP refractory to conservative treatment.

Low back pain is one of the main medical complaints worldwide, generating high social costs. The several potential causes for low back pain generate numerous differential diagnoses. 1 2 There are several facet joints, called zygoapophyseal joints, along the entire spine. These joints connect one vertebra to another, allowing the spine movement back and forth, 3 and promoting flexibility and stability. 4 The lumbar facet joints are a common source of pain. 1 2 These joints can present inflammation, wear, and tear resulting from trauma, repetitive movements, and several other factors, leading to facet syndrome, one of the main conditions causing back pain. 5 There is a consensus that the lumbar facet joints are among the most commonly affected by facet syndrome. The L4-L5 level is the most affected, followed by L5-S1. 5 After diagnosis, the initial therapy consists of rest, physical therapy to strengthen the core muscles around the spine, stretching, and oral medications, such as non-steroidal anti-inflammatory drugs (NSAIDs) and opioids. 6 Other techniques may be instituted if conservative treatment fails, such as medial branch block, neurolysis (chemical ablation), intra-articular steroid injections, and radiofrequency ablation (RFA). These techniques may be an alternative for patients who do not respond well to injections. 7 RFA or rhizotomy is a minimally invasive procedure consisting of inserting needles at specific points of the spine aided by fluoroscopy. Radiofrequency (RF) emits heat waves at the tip of the needle; heat leads to thermal injury and protein denaturation, resulting in sick tissue absorption and deactivation of the nerve branches responsible for painful sensitivity. 8 As such, these branches stop sending pain signals to the brain and spinal cord, relieving pain for approximately 12 months or more. 8 Nerve fibers subjected to RF may self-regenerate. 9 Because of this fact and other variables, its effectiveness is controversial. The present study analyzed the literature through a systematic review and gathered information about the traditional RFA in facet syndrome to demonstrate whether there is a consensus on the technique's effectiveness in relieving chronic low back pain (CLBP) refractory to conservative treatment.

This study is a systematic literature review based on queries at the PubMed, Scielo, Lilacs, and Medline databases; these last two databases were available from Biblioteca Virtual em Saúde (Virtual Health Library in Portuguese). Queries occurred in June and July 2022. The following terms were selected according to the Descriptors in Health Sciences/Medical Subject Headings (DeCS/MeSH): facet, pain, lumbar, and radiofrequency. This review followed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model for systematic reviews and meta-analyses. After paper selection, we read their titles and abstracts to determine which ones met the inclusion and exclusion criteria. The inclusion criteria for analysis were title, observational studies, clinical trials, comparative and clinical studies, English and Portuguese language, and publication over the past seventeen years (2005–2022). The exclusion criteria were papers addressing other themes and review articles. We analyzed the selected papers to extract the following data: first author, year of publication, study method, and final outcome of RFA in facet syndrome.

The electronic query yielded 142 publications with the established terms and filters. After reading the titles and abstracts and excluding 27 duplicate articles, we selected 12 papers for analysis ( Figure 1 ). All selected studies were double-blind randomized clinical trials and observational studies, totaling 972 patients. Table 1 10 11 12 13 14 15 16 17 18 19 20 21 summarizes the main features of each study, highlighting the author, year of publication, number of patients, their age and distribution, and the main conclusions. These studies showed that the traditional RFA was positive when performed in correctly selected patients. All patients suffered from CLBP due to involvement of the zygoapophyseal joint and had no pain relief with drug treatments. Most studies used the visual analog scale (VAS) for pain evaluation, in addition to the EQ-5D Quality-of-Life questionnaire, the Global Perceived Effect (GPE) questionnaire, and the Oswestry disability index (ODI). Patients undergoing the traditional RF reported improvement in low back pain and referred leg pain. 15 Some studies revealed no differences in 3 months between injection therapy and the ablation technique. 16 Other studies have shown that RF proved to be an alternative for pain relief for 6 months or more. 18 19 20 In the short term, the injection technique seems more advantageous but RF results in better outcomes in the long term. 20

This study is a systematic literature review to analyze the relevance of the traditional RFA ablation technique to treat chronic pain caused by facet syndrome. The idea of performing RFA by changing the traditional therapeutic target, the medial dorsal branch, to the joint capsule is more effective, providing a longer period of relief of the chronic pain resulting from facet syndrome. In addition, we observed that groups undergoing RFA obtained a clear improvement compared to control groups, thus showing the effectiveness of RFA on CLBP due to facet syndrome. 11 The use of different temperatures for RF neuroablation was effective even in 49 patients with pain due to a secondary etiology. 12 Outcomes regarding the effectiveness of neuroablation were equally effective in terms of different temperatures and time variables from each group. RF at 90 °C yielded better outcomes compared with a temperature of 80 °C. 12 Another study also confirmed the same fact by performing RF at 90 °C in one group of patients and at 80 °C in another set of subjects; in this paper, temperature was the only variable. 22 Those undergoing RF at 90 °C had a 3.1-times higher chance (p = 0.0004) of obtaining a functional improvement of at least 50% compared with those undergoing RF at 80 °C. 22 When comparing RF denervation and betamethasone injections using VAS, some studies found that both techniques resulted in the same outcomes in 6 months. 21 Two other studies reported a higher benefit of RF as a long-term treatment for chronic pain. 14 20 We can infer that the corticoid injection technique improves pain on an immediate and short-term basis. Corticoid injections are the first option in chronic pain cases before performing the RFA technique. In addition, it is a fundamental tool to confirm the pain originates from the facet joints. 23 The following parameters allow analyzes and outcome assessments: a pain diary using the VAS scale, including one for low back pain (VAS-back) and one for referred leg pain (VAS-leg); physical activities score; reports on the number of analgesic agents used in the last 24 hours; and the perceived GPE by the modified Likert scale. These parameters show a significant improvement in the VAS-back score of both groups undergoing RF or not (control) and in the VAS-leg score of the RF group. However, the evaluation of such outcomes must be careful because the blinding period ended in 3 months, and both groups had patients lost at follow-up. This study reported that the GPE score favored RF therapy in CLBP, mainly in elderly patients, females, patients with a history of chronic pain, working subjects, and patients with no history of lumbar surgery. 13 Radiograph as a guide for RFA was a positive technique. Patients undergoing radiographs achieved a 90% efficacy rate in the immediate period and a 67.5% rate at 6 months post-treatment. It is worth noting that it is believed that 79% of back pain cases result from conditions affecting the zygapophyseal joints. 14 The selection of patients for the ablation technique must be careful and based on a positive diagnostic block. Despite having a margin of error of 20 to 40% of false-positive results, the diagnostic block is still used to refer patients with CLBP for RF. 24

CLBP treatment is a challenge, but this systematic review suggests that the RFA technique is an effective therapy for these patients with pain caused by the involvement of the facet joint by the facet syndrome. Due to the significance of the subject, it is worth noting the need to develop new clinical studies to obtain more information on alternative treatments for facet syndrome. Furthermore, we highlight the importance of meticulously selecting patients undergoing RFA therapy.