Which one is more effective for the clinical treatment of chronic pain in knee osteoarthritis: radiofrequency neurotomy of the genicular nerves or intra-articular injection?

Minimally invasive interventional procedures for osteoarthritis and inflammatory arthritis: A systematic review and meta-analysis

OBJECTIVE

to summarize the evidence on the efficacy of minimally invasive interventional procedures such as radiofrequency ablation (RFA) and transcatheter arterial embolization (TAE) in patients with osteoarthritis or inflammatory arthritis.

METHODS

a literature search was conducted in PubMed and Web of Science databases. Both randomized controlled trials (RCTs) and non-randomized studies of interventions (NRSI) were included. The results were organized according to the treated anatomical site: knee, hip, foot and ankle, shoulder, hand and wrist, sacroiliac joints. Data about treatment efficacy were extracted. The main outcome was change in pain intensity using the 0-10 visual analog scale (VAS) from baseline to 1 month. Additional timepoints at 3, 6 and 12 months were assessed. Change in functional status was evaluated. Pooled estimates were calculated as the mean difference (MD) and 95 % confidence interval relative to baseline. The meta-analyses of RCTs and NRSI were conducted separately.

RESULTS

of the 4599 retrieved articles, 164 were included in the review and, considering all the established timepoints, 111 (38 RCTs and 73 NRSI) were selected for the meta-analysis. Only one article described patients with inflammatory arthritis. In the meta-analysis of RCTs, one month after the procedure, MD in VAS was -3.98 (-4.41 to -3.55; k = 21) for knee RFA, and -3.18 (-3.96 to -2.39; k = 8) for sacroiliac joints RFA. In the meta-analysis of NRSI, MD in VAS was -4.12 (-4.63 to -3.61; k = 23) for knee RFA, -3.84 (-4.77 to -2.92; k = 7) for knee TAE, -4.34 (-4.96 to -3.71; k = 2) for hip RFA, -3.83 (-4.52 to -3.15; k = 3) for shoulder RFA and -4.93 (-5.58 to -4.28; k = 14) for sacroiliac joints RFA. Significant decrease in pain intensity was found also at 3, 6 and 12 months. Additionally, functional status improved at all the assessed timepoints.

CONCLUSION

minimally invasive interventional procedures can improve pain and functional status of patients affected by OA or chronic sacroiliac pain of degenerative origin. Further research is warranted in the field of inflammatory rheumatic diseases.

Radiofrequency ablation versus intra-articular mesenchymal stem cell injection for knee osteoarthritis: a systematic review and network meta-analysis

BACKGROUND

Knee osteoarthritis (OA) is a prevalent degenerative disease and causes disability, pain and imposes a substantial burden on patients. Conventional treatments for knee OA show limited effectiveness. Consequently, innovative treatments, such as radiofrequency ablation (RFA) and intra-articular mesenchymal stem cells (IA MSC), have gained attention for addressing these limitations.

OBJECTIVE

We compared the efficacy of RFA and IA MSC for knee OA through a network meta-analysis (NMA).

EVIDENCE REVIEW

A literature search was conducted using PubMed, MEDLINE, Embase, Cochrane Library, Web of Science and handsearching. Randomized controlled trials (RCTs) comparing RFA or IA MSC to conventional treatments for knee OA were included. The primary outcomes comprised the pain score and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The clinical outcomes were compared using a frequentist approach, and the treatments were ranked using the surface under the cumulative ranking curve (SUCRA) values.

FINDINGS

We included 34 RCTs (n=2371). Our NMA revealed that RFA and IA MSC were significantly more effective than conventional treatments in managing pain at both 3 and 6 months with moderate certainty. Specifically, RFA demonstrated the highest SUCRA values, indicating its superior efficacy. For WOMAC scores, both RFA and MSC showed significant improvements at 3 months, with RFA maintaining its lead at 6 months, although MSC did not display significant superiority at this stage.

CONCLUSIONS

This analysis suggests that RFA and MSC are resilient treatment options in knee OA. Despite some study heterogeneity, these treatments consistently outperformed conventional treatments, particularly in the short to mid-term, although with varying levels of certainty in their efficacy.

PROSPERO REGISTRATION NUMBER

CRD42023492299.

Is radiofrequency ablation effective in treating patients with chronic knee osteoarthritis? A meta-analysis of randomized controlled trials

Background and aims

This meta-analysis aimed to evaluate the short-term and long-term efficacy of radiofrequency ablation (RFA) and explore the role of diagnostic genicular nerve blocks in predicting treatment outcomes.

Methods

A comprehensive literature search was conducted, and nine randomized controlled trials involving 714 participants were included in the analysis. Data extraction, risk of bias assessment, and subgroup analyses were performed. The primary outcome measures were pain scores at 6 and 12 months, assessed using visual analogue scale and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

Results

The meta-analysis revealed that RFA demonstrated a significant short-term efficacy in reducing pain compared to the control group at 6 months, as indicated by the pain scores [weighted mean difference (WMD): -2.69, 95% CI: -3.99, -1.40]. Similarly, WOMAC scores at 6 months favored the RFA group (WMD: -4.40, 95% CI: -7.12, -1.68). However, the long-term efficacy of RFA at 12 months remained uncertain for both pain scores (WMD: -0.88, 95% CI: -2.36, 0.61) and WOMAC (WMD: 0.03, 95% CI: -0.25, 0.32). Subgroup analysis suggested that a positive result from the diagnostic genicular nerve blocks test was associated with a more favourable short-term outcome.

Conclusion

This meta-analysis provides moderate-quality evidence supporting the short-term efficacy of RFA in reducing pain in patients with knee osteoarthritis. The inclusion of a diagnostic genicular nerve blocks test prior to RFA may help identify patients likely to benefit from the procedure. But it still needs more large sample studies to verify the results. However, further research is needed to determine the long-term efficacy of RFA in managing knee osteoarthritis pain.

IonicRF™: a novel step in technology for radiofrequency ablation treatments

Radiofrequency ablation (RFA) has been utilized since the 1970s to treat various painful conditions. The technology has evolved from its initial use to treat lumbar facet mediated pain with monopolar lesioning to now treat a plethora of chronic pain conditions. This article reviews Abbott Corporation's (IL, USA) IonicRF™ generator. The IonicRF generator utilizes an intelligent power algorithm that improves efficiency and reduces procedure time. The generator also carries a wide range of RFA therapies such as monopolar, bipolar, pulsed or pulsed dose radiofrequency. Additionally, the IonicRF RFA generator is compatible with the Simplicity™ RF probe (Abbott) which allows for efficient and effective denervation of the sacroiliac joint.

Comparison of the efficacy of genicular nerve phenol neurolysis and radiofrequency ablation for pain management in patients with knee osteoarthritis

Background

: Genicular nerve neurolysis with phenol and radiofrequency ablation (RFA) are two interventional techniques for treating chronic refractory knee osteoarthritis (KOA) pain. This study aimed to compare the efficacy and adverse effects of both techniques.

Methods

: Sixty-four patients responding to diagnostic blockade of the superior medial, superior lateral, and inferior medial genicular nerve under ultrasound guidance were randomly divided into two groups: Group P (2 mL phenol for each genicular nerve) and Group R (RFA 80°C for 60 seconds for each genicular nerve). The numeric rating scale (NRS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used to evaluate the effectiveness of the interventions.

Results

: RFA and phenol neurolysis of the genicular nerves provided effective analgesia within groups at 1 week, 1 month, and 3 months compared to baseline. There was no significant difference between the groups in terms of NRS and WOMAC scores at all measurement times. At the 3rd month follow-up, 50% or more pain relief was observed in 53.1% of patients in Group P and 50% of patients in Group R. The rate of transient paresthesia was 34.4% in Group P and 6.3% in Group R, and this was significantly higher in Group P.

Conclusions

: Neurolysis of the genicular nerves with both RFA and phenol is effective in the management of KOA pain. Phenol may be a good alternative to RFA. Further studies are needed on issues such as dose adjustment to prevent transient paresthesia response.

Can ultrasound-guided radiofrequency ablation of genicular nerves of the knee, be performed without locating corresponding arterial pulsations-a cadaveric study

INTRODUCTION

Given the rising prevalence of knee osteoarthritis, radiofrequency ablation of genicular nerves (RFA) has emerged as a promising treatment option for knee pain. The knee has an extremely complex and variable innervation with nearly 13 genicular nerves described. The frequently ablated genicular nerves are the superomedial (SMGN), the superolateral (SLGN), and the inferomedial (IMGN) genicular nerves. Conventionally, under ultrasound guidance, these nerves are ablated near the corresponding arterial pulsations, but due to the rich vascular anastomosis around the knee joint, identifying the arteries corresponding to these constant genicular nerves can be tedious unless guided by some bony landmarks. In this study, we have evaluated whether it is possible to accurately target these three genicular nerves by just locating bony landmarks under ultrasound in human cadaveric knee specimens.

METHODS

Fifteen formalin-fixed cadaveric knee specimens were studied. SMGN was targeted 1 cm anterior to the adductor tubercle in the axial view. For SLGN, in the coronal view, the junction of the lateral femoral condyle and shaft was identified, and at the same level in the axial view, the crest between the lateral and posterior femoral cortex was targeted. For IMGN in the coronal view, the midpoint between the most prominent part of the medial tibial condyle and the insertion of the deep fibers of the medial collateral ligament was marked. The medial end of the medial tibial cortex was then targeted at the same level in the axial view. The needle was inserted from anterior to posterior, with an in-plane approach for all nerves. Eosin, 2% W/V, in 0.1 ml was injected. Microdissection was done while keeping the needle in situ. Staining of the nerve was considered a positive outcome, and the percentage was calculated. The nerve-to-needle distance was measured, and the mean with an interquartile range was calculated.

RESULT

The accuracies of ultrasound-guided bony landmarks of SMGN, SLGN, and IMGN were 100% in terms of staining, with average nerve-to-needle distances of 1.67, 3.2, and 1.8 mm respectively.

CONCLUSION

It is with 100% accuracy, that we can perform RFA of SMGN, SLGN, and IMGN under ultrasound guidance, by locating the aforementioned bony landmarks.

Is Radiofrequency Ablation Superior to Intra-Articular Injections for the Treatment of Symptomatic Knee Osteoarthritis?-A Systematic Review

The radiofrequency ablation (RFA) is considered a valid, minimally invasive treatment modality for the management of symptomatic knee osteoarthritis (OA). The aim of this study was to compare the outcomes of RFA with that of commonly used intra-articular injections for the persistent knee pain due to OA. Medline/Pubmed and Scopus databases were systematically searched up to April 2023 to identify studies comparing the effect of RFA and intra-articular injections (IAIs) on knee OA. Nine studies including 899 patients fulfilled the eligibility criteria and were included in the systematic review. The RFA procedure was related with improved knee pain relief compared to IAIs at 3-, 6- and 12-month follow-up (p < 0.001). Similarly, functional improvement was greater in RFA treatment than that observed after hyaluronic acid (HA), steroid or platelet-rich plasma (PRP) injections (Visual Analogue Scale p < 0.001, Numeric Rating Scale p = 0.019, Western Ontario and McMaster University Osteoarthritis Index p = 0.012). The overall procedural complication rate of RFA was 10.2% and was higher than steroid (p = 0.023) and PRP (p = 0.017) injections. However, no severe adverse events were reported. For patients with symptomatic knee OA, RFA seems to be more effective than IAIs in alleviating pain and improving joint function, despite the relatively higher incidence of non-serious adverse events. However, due to the limited number of studies and patients, this result should be interpreted with caution and not be generalized to the entire knee OA population.

Comparison of conventional and cooled radiofrequency treatment of the genicular nerves versus sham procedure for patients with chronic knee pain: protocol for a multicentre, double-blind, randomised controlled trial (COGENIUS)

INTRODUCTION

The prevalence of chronic knee pain is increasing. Osteoarthritis (OA) and persistent postsurgical pain (PPSP) are two important causes of knee pain. Chronic knee pain is primarily treated with medications, physiotherapy, life-style changes and intra-articular infiltrations. A radiofrequency treatment (RF) of the genicular nerves is a therapeutical option for refractory knee pain. This study investigates the effectiveness and cost-effectiveness of conventional and cooled RF in patients suffering from chronic, therapy resistant, moderate to severe knee pain due to OA and PPSP.

METHODS AND ANALYSIS

The COGENIUS trial is a double-blinded, randomised controlled trial with 2-year follow-up. Patients and outcome assessors are blinded. Patients will be recruited and treated in Belgium and the Netherlands. All PPSP after a total knee prothesis and OA patients (grades 2-4) will undergo a run-in period of 1-3 months where conservative treatment will be optimised. After the run-in period, 200 patient per group will be randomised to conventional RF, cooled RF or a sham procedure following a 2:2:1 ratio. The analysis will include a comparison of the effectiveness of each RF treatment with the sham procedure and secondarily between conventional and cooled RF. All comparisons will be made for each indication separately. The primary outcome is the Western Ontario and McMaster Universities Osteoarthritis Index score at 6 months. Other outcomes include knee pain, physical functionality, health-related quality of life, emotional health, medication use, healthcare and societal cost and adverse events up to 24 months postintervention.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of the University of Antwerp (Number Project ID 3069-Edge 002190-BUN B3002022000025), the Ethics committee of Maastricht University (Number NL80503.068.22-METC22-023) and the Ethics committee of all participating hospitals. Results of the study will be published in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05407610.

Comparison of cooled versus conventional radiofrequency treatment of the genicular nerves for chronic knee pain: a multicenter non-inferiority randomized pilot trial (COCOGEN trial)

BACKGROUND

Radiofrequency (RF) treatment of the genicular nerves has the potential to reduce chronic knee pain due to osteoarthritis or persistent postsurgical pain, however, a direct comparison between the two main modalities used, conventional and cooled, is lacking.

METHODS

This double blind, non-inferiority, pilot, randomized controlled trial compared the effects of cooled and conventional RF in chronic knee pain patients suffering from osteoarthritis or persistent postsurgical pain after total knee arthroplasty. Patients were randomized following a 1:1 rate. The primary outcome was the proportion of patients with ≥50% pain reduction at 3 months postintervention. Other outcomes were knee pain, functionality, quality of life, emotional health, and adverse events up to 6 months postintervention. Conventional RF treatment was tested for non-inferiority to cooled in reducing knee pain at 3 months follow-up.

RESULTS

Forty-nine of 70 patients were included, of which 47 completed a 3-month follow-up. The primary outcome was achieved in 4 of 23 patients treated with conventional RF (17%) vs in 8 of 24 with cooled (33%) (p=0,21). Results from the non-inferiority comparison were inconclusive in relation to the non-inferiority margin. There was no statistically significant difference between secondary outcomes. There were no serious adverse events.

CONCLUSIONS

Both conventional and cooled RF treatment reduced pain in the osteoarthritis and persistent postsurgical pain population. This pilot study did not demonstrate statistically significant differences in the proportion of patients experiencing ≥50% pain reduction between techniques. The non-inferiority analysis was inconclusive. These results warrant further research.

TRIAL REGISTRATION NUMBER

NCT03865849.

Consensus Guidelines on Interventional Therapies for Knee Pain (STEP Guidelines) from the American Society of Pain and Neuroscience

Knee pain is second only to the back as the most commonly reported area of pain in the human body. With an overall prevalence of 46.2%, its impact on disability, lost productivity, and cost on healthcare cannot be overlooked. Due to the pervasiveness of knee pain in the general population, there are no shortages of treatment options available for addressing the symptoms. Ranging from physical therapy and pharmacologic agents to interventional pain procedures to surgical options, practitioners have a wide array of options to choose from – unfortunately, there is no consensus on which treatments are “better” and when they should be offered in comparison to others. While it is generally accepted that less invasive treatments should be offered before more invasive ones, there is a lack of agreement on the order in which the less invasive are to be presented. In an effort to standardize the treatment of this extremely prevalent pathology, the authors present an all-encompassing set of guidelines on the treatment of knee pain based on an extensive literature search and data grading for each of the available alternative that will allow practitioners the ability to compare and contrast each option.

Cooled and traditional thermal radiofrequency ablation of genicular nerves in patients with chronic knee pain: a comparative outcomes analysis

INTRODUCTION

Genicular nerve radiofrequency ablation (GNRFA) is a minimally invasive intervention for patients with chronic knee pain (CKP) not responding to conservative treatments. Few investigations have compared treatment outcomes of cooled-RFA (c-RFA) and thermal-RFA (t-RFA), two common approaches of GNRFA. This study aims to investigate and compare outcomes, including probability of treatment success, between c-RFA and t-RFA in patients with CKP.

METHODS

This retrospective cohort study analyzed a total of 208 propensity score matched patients, including 104 patients who received c-RFA and 104 patients who received t-RFA. The primary outcome was probability of pain relief after the procedure, defined as reduction in Numeric Rating Scale (NRS) pain score of 2 or greater. The secondary outcomes were degree of NRS pain score reductions, duration of relief, and the probability of patients receiving TKA within 1 year of treatment.

RESULTS

T-RFA was associated with a higher probability of pain relief within 1, 3, and 6 months after procedure when compared with c-RFA. Probabilities of pain relief from t-RFA and c-RFA were 62% (95% CI 51% to 71%) and 43% (95% CI 34% to 53%; p=0.01) within 1 month, 78% (95% CI 68% to 85%) and 55% (95% CI 45% to 64%; p<0.001) within 3 months, and 79% (95% CI 70% to 86%) and 59% (95% CI 49% to 68%; p<0.01) within 6 months, respectively. t-RFA was also associated with greater mean NRS pain score reduction at 1 month after procedure: -4.71 (95% CI -5.3 to -4.1) when compared with -3.59 (95% CI -4.3 to -2.9; p=0.02) from c-RFA. T-RFA and c-RFA were comparable in pain score reduction at 3, 6, 9 and 12 months after procedure. Both groups demonstrated comparable duration of relief and probability of patients receiving TKA within 1 year.

DISCUSSION

Both t-RFA and c-RFA effectively reduced NRS pain scores in most patients with CKP within the 1 year follow-up period. Genicular nerve t-RFA was associated with a higher probability of treatment success and a greater degree of pain relief at 1 month after the procedure when compared with c-RFA in propensity score matched patients with CKP.

Cooled Radiofrequency Ablation Provides Prolonged Pain Relief Compared to Traditional Radiofrequency Ablation: A Real-World, Large Retrospective Clinical Comparison from a Single Practice

Background

Genicular radiofrequency ablation is an established therapy for chronic knee pain. An analysis comparing different probe sizes and technologies has not yet been undertaken for this indication. This large retrospective, comparison study from a single-center comprehensive pain management practice aims to do that.

Methods

Outcomes of 170 patients who underwent traditional radiofrequency ablation (tRFA) for chronic knee pain were compared to 170 consecutive patients who received cooled radiofrequency ablation (CRFA) with similar (p=0.5) pre-procedural pain scores.

Results

The VAS pain score at the first post-procedure visit at 4–6 weeks decreased to 5.07±2.8 cm for tRFA and to 4.26 ± 3.2 cm for CRFA (p<0.001 for both from baseline). The difference was profound and significantly better in the favor of CRFA (p<0.001) as the duration of reduction of pain scores by greater than 50% was 2.6 months for tRFA and 11.1 months for CRFA. There were only 15 patients (8.8%) who continued to receive >50% of pain relief in tRFA at 12 months, as opposed to 78 (46%) at 12 months for CRFA. We compared the initial outcomes and long-term pain relief. Long-term outcomes were better for the bigger lesion size treatment group patients.

Conclusion

We conclude that the duration and intensity of pain relief were of a greater magnitude after the larger diameter probe cooled RFA.

Total Knee Arthroplasty After Genicular Nerve Radiofrequency Ablation: Reduction in Prolonged Opioid Use Without Increased Postsurgical Complications

Genicular nerve radiofrequency ablation (GNRFA) is an increasingly used nonsurgical treatment modality for patients with advanced knee osteoarthritis. Previous studies have demonstrated this to be an effective and safe method to decrease pain and increase functionality in this patient population. The purpose of this study was to compare 2-year postoperative complication rates and rates of prolonged postoperative opioid usage between patients undergoing total knee arthroplasty (TKA) after previous GNRFA and those undergoing TKA alone.

Editorial Commentary: Radiofrequency Ablation for Patients With Osteoarthritis of the Knee Could Be Indicated for Patients Failing Conventional Nonoperative Treatment and Wishing to Avoid Total Knee Arthroplasty

Patients with knee osteoarthritis are constantly looking for ways to combat their pain and improve their quality of life. As newer treatments present themselves, it is up to the orthopaedic specialists to provide the best treatment possible. Radiofrequency ablation, usually administered by a pain management specialist, has shown to be an acceptable alternative treatment and should be considered in the management of osteoarthritis. It should be considered for patients who have failed nonoperative treatments and are not interested in pursuing total knee arthroplasty, and possibly for patients who have persistent pain after total knee arthroplasty.

Radiofrequency Ablation in Cooled Monopolar or Conventional Bipolar Modality Yields More Beneficial Short-Term Clinical Outcomes Versus Other Treatments for Knee Osteoarthritis: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

PURPOSE

To evaluate various radiofrequency ablation (RFA) treatments for knee osteoarthritis (OA) and determine the best modality, target, number of electrodes, and image guidance for improving knee pain and function.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) comparing the efficacy of RFA treatments for knee OA from inception up to September 30, 2021. The primary outcome was the visual analog scale (VAS), and the secondary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Bayesian network meta-analysis was performed to synthesize the mean difference (MD) and rank the comparative effectiveness of treatments.

RESULTS

A total of 21 eligible RCTs (from 2011 to 2021, involving 1,818 patients) with 8 RFA treatments, 6 intra-articular injections, NSAIDS, exercise, and placebo were assessed. Conventional bipolar genicular nerve RFA (GNRFA) had the greatest net benefit on the VAS at 6 months (MD, -5.5; 95% confidence interval [CI], -4.3 to -6.7; SUCRA, .98). And cooled monopolar GNRFA had the greatest net benefit on the WOMAC at 6 months (MD, -33; 95% CI, -37 to -29; SUCRA, .99). In conventional and pulsed modalities, bipolar RFA was associated with a significant decrease in VAS and WOMAC than monopolar RFA. Combining pulsed intra-articular RFA and platelet-rich plasma injection had no additional positive effects on VAS or WOMAC at 3 months.

CONCLUSIONS

RFA is effective in improving both knee pain and function in patients with OA, at least in the short term (6 months). Patients respond better to the cooled modality than the conventional and pulsed modalities. Bipolar is more effective than monopolar for improving pain and function in conventional and pulsed modalities. Fluoroscopy and ultrasound guidance showed no differences in improving pain and function. The effectiveness of RFA in cooled modality using bipolar or in combination with various intra-articular injections remains to be compared.

LEVEL OF EVIDENCE

II, systematic review and meta-analysis of Level I and II studies.

Cooled radiofrequency ablation of the genicular nerves for chronic pain due to osteoarthritis of the knee: a cost-effectiveness analysis compared with intra-articular hyaluronan injections based on trial data

Background

Effective symptom control in painful knee osteoarthritis (OA) may improve patient quality of life. In a randomised crossover trial (NCT03381248), COOLIEF* cooled radiofrequency ablation (CRFA) reduced pain and stiffness and improved physical function and quality of life compared with intra-articular hyaluronan (HA) injections. The present study aimed to establish the cost effectiveness of CRFA versus intra-articular HA injections for treating moderate-to-severe OA knee pain from a US Medicare perspective.

Methods

We conducted a cost-effectiveness analysis using utility data (EQ-5D) from the randomised crossover trial of CRFA versus intra-articular HA injections, which had follow-ups at 1, 3, 6, and 12 months. Patients in the HA group with unsatisfactory outcomes (e.g., continued pain) at 6 months could cross over to CRFA. Economic analysis outcomes included quality-adjusted life-years (QALYs), costs, and cost effectiveness (cost per QALY gained). Base-case analyses were modelled on a 6-month time horizon (to trial crossover). Due to limited trial data in the HA arm beyond 6 months, scenarios explored potential outcomes to 12 months if: 1) Utility with HA persisted for a further 6 months; 2) A second HA injection was received at 6 months and achieved the same utility change for the second 6 months. In both scenarios, the CRFA arm used trial data for patients who received CRFA from baseline to 12 months. Alternative costing scenarios were also explored.

Results

CRFA resulted in an incremental QALY gain of 0.020 at an incremental cost of US$1707, equating to an incremental cost-effectiveness ratio (ICER) of US$84,392 per QALY over 6 months, versus intra-articular HA injections. Extending the analysis to 12 months and assuming persistence in utility in the HA arm resulted in a larger utility gain for CRFA (0.056 QALYs) and a lower ICER of US$30,275 per QALY. If patients received a second HA injection, the incremental benefit of CRFA out to 12 months was reduced (QALY gain 0.043) but was offset by the costs of the second HA injection (incremental cost US$832). This resulted in an ICER of US$19,316 per QALY.

Conclusions

CRFA is a cost-effective treatment option for patients with OA-related knee pain considering the typical US threshold of US$100,000/QALY.

Ultrasound-guided monopolar versus bipolar radiofrequency ablation for genicular nerves in chronic knee osteoarthritis pain: A randomized controlled study

Background

This study compared between monopolar and bipolar radiofrequency (RF) ablation of the genicular nerves using ultrasound guidance (USG) in chronic knee osteoarthritis pain.

Material and methods

This was a prospective, randomized, double-blind study. Fifty patients with knee osteoarthritis pain were equally randomized to either monopolar or bipolar groups. The primary outcome was visual analogue score (VAS). The secondary outcomes were the proportion of successful responders with a reduction of 50% of VAS score at 12 and 24 weeks, the procedure time and pain and oxford knee score (OKS).VAS and OKS were recorded at 1, 4, 12, 24 weeks after intervention. Any complications were reported.

Results

Mean VAS score in bipolar group was (p < 0.05) lower than monopolar group at 12 weeks [4.84 ± 0.62 Vs. 3.56 ± 0.71] and 24 weeks [5.44 ± 0.82 Vs. 3.96 ± 0.79]. The Proportion of successful responders with a reduction of at least 50% of VAS score were more in bipolar group than monopolar group at 12 weeks (80% Vs. 12%) and 24 weeks (44% Vs. 4%). Mean OKS score in bipolar group was (p < 0.05) lower than monopolar group at 12 weeks [26 ± 3 Vs. 34 ± 3] and 24 weeks [27 ± 3 Vs. 35 ± 3].The procedure time and pain were (p < 0.05) lower in monopolar than bipolar group. The complications were similar in both groups.

Conclusion

USG bipolar RF ablation is more effective than monopolar RF ablation in controlling knee osteoarthritis pain as for the duration and severity of pain without fluoroscopic confirmation.

•

A study on 50 patient undergoing USG RFA of genicular nerves of 2 groups; Monopolar or bipolar RFA.

•

Bipolar RFA is more effective than Monopolar RFA.

•

USG radiofrequency ablation is alternative to fluoroscopic RFA.

•

No significant difference between the two groups according to complications.

Effectiveness of the Thermal Genicular Nerve Radiofrequency Ablation Therapy Under Fluoroscopy in Patients with Non-operative Advanced Stage Knee Osteoarthritis: 1-Year Follow-Up Results

BACKGROUND

In this study, our aim was to present the 1-year results of the effect of thermal genicular nerve radiofrequency ablation (GNRFA) therapy on pain and functional outcomes in patients with advanced knee osteoarthritis.

MATERIALS AND METHODS

After retrospectively examining the hospital records, 49 knees of 35 patients who had undergone thermal RFA of the superior medial, superior lateral, and inferior medial branches of the genicular nerve under fluoroscopic guidance between July 2019 and December 2020 were included in the study. The visual analog scale (VAS) scores of the patients were recorded before RFA, on the day of RFA, and at the first, sixth, and 12th months postoperatively, as well as their Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores before RFA and at the 12th month postoperatively. Complications developed after the procedure and during the follow-up period were screened.

RESULTS

Twenty-five of the patients were females and 10 males, with a mean age of 77.3 ± 7.9 years (range 61-92 years). The mean VAS score was 8.4 ± 0.9 before RFA, and as 1.7 ± 1.0 right after the procedure, 2.4 ± 1.7 at the first month, 3.4 ± 1.8 at the sixth month, and 4.4 ± 1.9 at the 12th month (p < 0.01). In terms of the WOMAC score, the average value was 69.7 ± 6.4 before the treatment and 36.1 ± 11.8 at the final follow-up at the 12th month (p < 0.01). No complications were observed in any patient during the treatment or the follow-up period.

CONCLUSION

Non-surgical thermal GNRFA therapy of knee osteoarthritis provides significant outcomes in terms of pain and functionality, with no significant systemic or local side effects. Therefore, the technique can be considered as an alternative to other methods when treating advanced osteoarthritis.

Efficacy of Radiofrequency as Therapy and Diagnostic Support in the Management of Musculoskeletal Pain: A Systematic Review and Meta-Analysis

Radiofrequency (RF) is a minimally invasive procedure used to interrupt or alter nociceptive pathways for treating musculoskeletal pain. It seems a useful tool to relieve chronic pain syndromes, even if, to date, solid evidence is still needed about the effectiveness of this therapy. By this systematic review and meta-analysis, we aimed to evaluate the efficacy of RF in treating musculoskeletal pain. PubMed, Medline, Cochrane, and PEDro databases were searched to identify randomized controlled trials (RCTs) presenting the following: patients with chronic musculoskeletal pain as participants; RF as intervention; placebo, anesthetic injection, corticosteroid injection, prolotherapy, conservative treatment, physiotherapy, and transcutaneous electrical nerve stimulation as comparisons; and pain and functioning as outcomes. Continuous random-effect models with standardized mean difference (SMD) were used to compare the clinical outcomes. Overall, 26 RCTs were eligible and included in the systematic review. All of them analyzed the efficacy of RF in four different regions: cervical and lumbar spine, knee, sacroiliac (SI) joint, shoulder. The outcomes measures were pain, disability, and quality of life. A medium and large effect in favor of the RF treatment group (SMD < 0) was found for the shoulder according to the Visual Analogical Scale and for the SI joint according to the Oswestry Disability Index. A small effect in favor of the RF treatment group (SMD > 0) was found for the spine according to the 36-item Short Form Survey. Non-significant SMD was found for the other outcomes. RF represents a promising therapy for the treatment of chronic musculoskeletal pain, especially when other approaches are ineffective or not practicable. Further studies are warranted to better deepen the effectiveness of RF for pain and joint function for each anatomical region of common application.

Efficacy and safety of radiofrequency treatment for improving knee pain and function in knee osteoarthritis: a meta-analysis of randomized controlled trials

Background

The clinical utility of radiofrequency (RF) in patients with knee osteoarthritis (OA) remains unclear. We conducted a meta-analysis to systematically evaluate the efficacy and safety of RF treatment in patients with knee OA.

Methods

Searches of the PubMed, Web of Science, EMBASE, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Data databases were performed through August 30, 2021. The major outcomes from published randomized controlled trials (RCTs) involving patients with knee OA were compared between RF and control groups, including Visual Analogue Scale (VAS) or Numerical Rating Scale (NRS) scores, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), Global Perceived Effect (GPE) scale, and adverse effects at available follow-up times.

Results

Fifteen RCTs involving 1009 patients were included in this meta-analysis, and the results demonstrated that RF treatment correlated with improvements in pain relief (VAS/NRS score, all P < 0.001) and knee function (WOMAC, all P < 0.001) at 1–2, 4, 12, and 24 weeks after treatment as well as patients’ degree of satisfaction with treatment effectiveness (GPE scale, 12 weeks, P < 0.001). OKSs did not differ significantly between the two groups. Moreover, treatment with RF did not significantly increase adverse effects. Subgroup analysis of knee pain indicated that the efficacy of RF treatment targeting the genicular nerve was significantly better than intra-articular RF at 12 weeks after treatment (P = 0.03).

Conclusions

This meta-analysis showed that RF is an efficacious and safe treatment for relieving knee pain and improving knee function in patients with knee OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02906-4.

Comparison of Minimally Invasive Procedures to Treat Knee Pain Secondary to Osteoarthritis: A Systematic Review and Meta-Analysis

PURPOSE

To review and indirectly compare the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.

MATERIALS AND METHODS

A literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostate artery embolization (PAE). Data on the following variables were included: international Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), quality of life (QoL), and post-void residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect.

RESULTS

No significant difference in outcomes between therapies were noted for IPSS at the 3-, 6-, and 12-month follow-ups. Although outcomes for rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation vs PAE vs Rezum. TURP PVR was significantly better than Urolift at 3-, 6-, and 12 months. No significant differences in minor or major AEs were noted.

CONCLUSION

Although significant differences in outcomes were limited, aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while aquablation has limited high quality data and has been associated with bleeding-related complications.

Long non-coding RNA LINC00265 promotes proliferation, apoptosis, and inflammation of chondrocytes in osteoarthritis by sponging miR-101-3p

Long non-coding RNAs (lncRNAs) play a part in a wide variety of diseases, including osteoarthritis (OA). This study was designed to investigate the biological role of lncRNA LINC00265 in OA and its underlying mechanisms. We examined the levels of LINC00265 and miR-101-3p using RT-qPCR, inflammatory factors using ELISA, and caspase-3, c-caspase-3, Bcl-2, Bax, and MMP-13 levels using Western blot in normal and OA chondrocytes, analysed the relationship between LINC00265 and miR-101-3p using bioinformatics analysis and luciferase reporter assays, performed loss- and gain-of-function analyses. The results showed that (1) LINC00265 expression was increased in OA chondrocytes, (2) si-LINC00265 inhibited OA chondrocyte apoptosis and inflammation, and (3) LINC00265 overexpression promoted normal and OA chondrocyte apoptosis and inflammation. Furthermore, we predicted and confirmed that miR-101-3p was a target of LINC00265. LINC00265 negatively regulated miR-101-3p in OA chondrocytes and LINC00265 promoted OA and normal chondrocyte apoptosis via miR-101-3p. Overall, lncRNA LINC00265 regulates chondrocyte apoptosis by acting as a sponge of miR-101-3p in OA.

Knee Ablation Approaches

Genicular nerve radiofrequency ablation has quickly become one of the most promising interventions for chronic knee pain secondary to osteoarthritis, with consistent improvements in pain and function. Although there are multiple techniques using slightly variable lesion locations, cannulas, lesion types, and imaging modalities, the clinical effectiveness targeting the anterior branches of the superior medial, superolateral, and inferior medial has reproducibly demonstrated clinically and statistically significant improvements up to 24 months after the procedure with minimal adverse events. This article summarizes the current knowledge of the sensory innervation of the knee joint, the principles of radiofrequency ablation, and the current literature on clinical outcomes.

Functional outcomes and physical performance of knee osteoarthritis patients after ultrasound-guided genicular nerve radiofrequency ablation

OBJECTIVE

To elucidate the effectiveness of ultrasound-guided genicular nerve radiofrequency ablation in alleviating pain as well as its effects on functional outcomes, quality of life and physical performance in knee osteoarthritis patients.

DESIGN

Prospective observational study.

SETTING

Patients were recruited within one community hospital.

SUBJECTS

Patients with knee osteoarthritis.

METHODS

The subjects underwent ultrasound-guided radiofrequency ablation of genicular nerves after showing a positive response to a diagnostic block. Outcome assessments were performed at baseline and at 2 and 12 weeks posttreatments using the 36-item Short Form Health Survey (SF-36), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a physical performance evaluation including balance tests, quadriceps muscle strength test, two-minute walking test and knee joint proprioception test.

RESULTS

Thirteen out of 38 patients were eligible for genicular nerve radiofrequency ablation. There were significant improvements from baseline to posttreatment in the numeric rating scale score, physical health domain score of SF-36, and pain and stiffness domain scores of the WOMAC. Regarding physical performance, the step test result significantly improved over the 12 weeks of follow-up. On the other hand, no significant deteriorations in the single leg stance test, isokinetic quadriceps muscle strength test, knee joint proprioception test or two-minute walking test results were observed after radiofrequency ablation of genicular nerves.

CONCLUSIONS

Radiofrequency ablation of genicular nerves may significantly alleviate pain and improve functional outcomes in knee osteoarthritis patients. More importantly, static balance control and quadriceps muscle strength were preserved and there was a change of proprioception in the good direction.

Latest Evidence-Based Application for Radiofrequency Neurotomy (LEARN): Best Practice Guidelines from the American Society of Pain and Neuroscience (ASPN)

Radiofrequency neurotomy (RFN), also known as radiofrequency ablation (RFA), is a common interventional procedure used to treat pain from an innervated structure. RFN has historically been used to treat chronic facet-joint mediated pain. The use of RFN has more recently expanded beyond facet-joint mediated pain to peripherally innervated targets. In addition, there has also been the emergence of different radiofrequency modalities, including pulsed and cooled RFN. The use of RFN has been particularly important where conservative and/or surgical measures have failed to provide pain relief. With the emergence of this therapeutic option and its novel applications, the American Society of Pain and Neuroscience (ASPN) identified the need for formal evidence-based guidance. The authors formed a multidisciplinary work group tasked to examine the latest evidence-based medicine for the various applications of RFN, including cervical, thoracic, lumbar spine; posterior sacroiliac joint pain; hip and knee joints; and occipital neuralgia. Best practice guidelines, evidence and consensus grading were provided for each anatomical target.

Genicular Nerve Anatomy and Its Implication for New Procedural Approaches for Knee Joint Denervation: A Cadaveric Study

OBJECTIVE

To verify the articular branch contributions in the human knee, delineate their anatomical variance, and outline the limitations of currently applied procedure protocols for denervation of the knee joint.

DESIGN

A detailed anatomical dissection.

SETTING

Cadavers in residence at the Albert Einstein College of Medicine.

SUBJECTS

In total, 24 lower extremity specimens from 14 embalmed cadavers.

METHODS

Human cadaveric dissections were performed on 24 lower extremities from 14 embalmed cadavers.

RESULTS

This cadaveric study has demonstrated that the anterior knee receives sensory innervations from SMGN, SLGN, LRN, NVI, NVL, RFN, and IMGN. The courses of SMGN, SLGN, RFN, and IMGN are similar to recent anatomical studies. However, discrepancies exist in their relative anatomy to bony and radiographic landmarks.

CONCLUSIONS

Genicular denervation using classical anatomical landmarks may not be sufficient to treat the anterior knee joint pain. Our findings illustrate more accurate anatomic landmarks for the three-target paradigm and support additional targets for more complete genicular denervation. This cadaveric study provides robust anatomical findings that can provide a foundation for new anatomical landmarks and targets to improve genicular denervation outcomes.

Genicular Nerve Radiofrequency Ablation for the Treatment of Painful Knee Osteoarthritis: Current Evidence and Future Directions

Genicular nerve radiofrequency ablation (RFA) is increasingly being performed to treat chronic pain due to knee osteoarthritis (KOA). This narrative review provides a concise summary of the relevant neuroanatomy, randomized controlled trials, appropriate patient selection, and safety relating to genicular RFA. Cadaveric studies demonstrate significant variability in the location of the genicular nerves, which has stimulated debate about the ideal target locations for genicular RFA. Despite this, favorable outcomes have been observed in studies targeting only the superior medial genicular nerve, inferior medial genicular nerve, and superior lateral genicular nerve. Several randomized controlled trials demonstrate superiority of genicular RFA compared with intra-articular steroid, viscosupplementation, and oral analgesics. Genicular RFA of the superior medial genicular nerve, inferior medial genicular nerve, and superior lateral genicular nerve appears to be an effective treatment for painful KOA, but targeting additional sensory nerves may further improve treatment success. Although genicular RFA appears relatively safe on the basis of the available data, additional large-scale studies are needed to provide greater confidence.

Is preoperative genicular radiofrequency ablation effective for reducing pain following total knee arthroplasty? A pilot randomized clinical trial

BACKGROUND AND OBJECTIVE

Although total knee arthroplasty (TKA) is an effective treatment for severe knee osteoarthritis (OA), a subset of patients experience significant postoperative pain and dissatisfaction. Several clinical trials support the analgesic benefits of genicular nerve radiofrequency ablation (GN-RFA) for non-operative knee OA, but only one prior trial has examined the effects of this intervention given preoperatively on postoperative outcomes following TKA, showing no analgesic benefit of cooled GN-RFA. The current study evaluated whether conventional thermal GN-RFA performed preoperatively resulted in significant improvements in pain and function following TKA.

METHODS

This was a single-center, prospective, randomized, sham-controlled, double-blinded pilot trial in which patients received either conventional GN-RFA (n=30) or sham (n=30) between 2 and 4 weeks prior to their TKA. Baseline measures were obtained preprocedurally on the day of intervention, with follow-up outcomes obtained preoperatively on the day of surgery, and at 2 and 6 weeks postoperatively.

RESULTS

Patients receiving GN-RFA showed no significant improvements relative to sham controls in the primary outcome, pain intensity at rest at 6-week follow-up. Secondary outcomes, including pain with ambulation and physical function, also showed no significant differences between groups at any follow-up assessment.

CONCLUSIONS

Conventional GN-RFA of the superior lateral, superior medial, and inferior medial genicular nerves when performed prior to TKA did not provide clinically significant pain relief or improvement in functional status at 2 or 6 weeks postoperatively.

TRIAL REGISTRATION NUMBER

NCT02947321.

Osteoarthritis-Related Knee Pain Treated With Genicular Artery Embolization: A Systematic Review and Meta-analysis

BACKGROUND

Genicular artery embolization (GAE) is an innovative technique that has been investigated as a supplementary treatment method for chronic pain secondary to knee osteoarthritis (OA).

PURPOSE

To evaluate the current evidence on the effectiveness and safety of GAE for OA-related knee pain.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic literature search was conducted in the PubMed, Web of Science, EMBASE, and Scopus databases to identify studies related to knee OA treated with GAE. Treatment agents were categorized as Embozene, imipenem/cilastatin, resorbable microspheres, and polyvinyl alcohol. The main outcomes were the mean difference (MD) in pre- and postembolization pain based on the visual analog scale (VAS) or the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores as well as changes in the need for pain medication. Random- and fixed-effects models were applied for data analysis.

RESULTS

Of 379 initially inspected publications, 11 (N = 225 patients; 268 knees) were included in the final review. The quality of the studies was fair in 8 and poor in 3-categorized according to the National Institutes of Health quality assessment tool. Overall, 119, 72, 13, and 21 patients were treated with imipenem/cilastatin, Embozene, resorbable microspheres, and polyvinyl alcohol, respectively. Symptomatic improvement was reported in all studies. The pooled effect size, characterized by MD, showed a significant improvement in the VAS and WOMAC pain scores, with better functional status after GAE. Pre- versus postembolization MDs in VAS scores ranged from 32 within the first week to 58 after a 2-year follow-up (equivalent to 54% and 80% improvement, respectively). There was a similar trend in the overall WOMAC scores, with MDs ranging from 28.4 to 36.8 (about 58% and 85% improvement, respectively). GAE resulted in a decreased need for pain medication for knee OA, with a 27%, 65%, and 73% decline in the number of patients who used opioids, nonsteroidal anti-inflammatory drugs, and intra-articular hyaluronic acid injection, respectively (P < .00001 for all). No significant difference between embolic agents was seen with regard to post-GAE pain reduction. No severe or life-threatening complications were reported.

CONCLUSION

OA treated by GAE using different embolic particles can be considered generally safe, with good efficacy and no reported serious complications.

Pain relief following genicular nerve radiofrequency ablation: does knee compartment matter?

Aim: To investigate the effect of knee osteoarthritis (OA) compartment location on pain relief following genicular radiofrequency ablation. Materials & methods: A retrospective chart review was performed on 62 patients. Visual analog scale scores at 3 and 6 months post procedure were compared with baseline and between compartment groups. Results: Pain significantly improved for all patients at 3 and 6 months (p < 0.001 and p = 0.005, respectively). Medial compartment OA was a significant predictor of improvement at 3 months (p = 0.042). Patellofemoral compartment OA was a significant predictor for a higher visual analog scale at 3 months (p = 0.018). Conclusion: Compartmental location of knee OA impacts pain relief following genicular radiofrequency ablation. Future protocols could target nerves based on which compartments are more affected on imaging.

Efficacy and safety of radiofrequency ablation for treatment of knee osteoarthritis: a meta-analysis of randomized controlled trials

Objective

To evaluate the efficacy and safety of radiofrequency ablation for the treatment of knee osteoarthritis.

Methods

A literature review was conducted using the PubMed, Cochrane Review, Embase, and Google Scholar databases. Two reviewers independently assessed the eligibility of all retrieved studies. The research was reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to ensure the reliability and verity of the results. The statistical analysis was performed using STATA version 13.0.

Results

Nine randomized controlled trials were collected for the data extraction and meta-analysis. Significant differences in the pain score at 4, 12, and 24 weeks were found between patients treated with radiofrequency ablation and those treated with placebo. Furthermore, the use of radiofrequency ablation was associated with an improved outcome of the Western Ontario and McMaster Universities Arthritis Index at 4, 12, and 24 weeks. No serious adverse events were observed in any patients who underwent radiofrequency ablation.

Conclusion

Radiofrequency ablation is efficacious and safe for reducing pain and improving knee function in patients with knee osteoarthritis, without increasing the risk of adverse effects.

Effectiveness of Combined Treatment Using Physical Exercise and Ultrasound-Guided Radiofrequency Ablation of Genicular Nerves in Patients with Knee Osteoarthritis

Radiofrequency (RF) is a mini-invasive neuromodulation intervention that is commonly used in chronic pain conditions including general musculoskeletal pain related to several diseases, including knee osteoarthritis (KOA). However, to date, few studies investigated synergistic therapeutic approaches combining RF with rehabilitative physical exercise protocols in KOA patients. This prospective cohort study aimed at assessing the short-term effects on pain in KOA patients of a multimodal intervention consisting of ultrasound (US)-guided RF geniculate ablation and concomitant rehabilitative physical exercise. We included grade III KOA patients with knee pain (Numerical Pain Rating Scale, NPRS >4) not responsive to conventional treatments. They underwent a combined intervention including US-guided RF geniculate ablation and a 2-week physical exercise program. At the baseline (T0) and 1 month after (T1) we assessed: NPRS, Knee Injury and Osteoarthritis Outcome Scale (KOOS), quality of life, exercise adherence, and safety. All the 47 KOA patients enrolled (68.8 ± 13.7 years old) showed a reduction of pain (NPRS: 7.48 ± 1.74; 3.63 ± 1.68; p < 0.001). In addition, there was a significant improvement (p < 0.05) also in the other functioning and HRQoL outcomes. Adherence to the exercise program was over 80% in more than half (28) of the patients. No major adverse events were reported. These findings suggested that US-guided RF ablation of genicular nerves combined with rehabilitative exercise therapy might be considered a safe and effective approach in the complex management of KOA patients.

Thermal Nerve Radiofrequency Ablation for the Nonsurgical Treatment of Knee Osteoarthritis: A Systematic Literature Review

BACKGROUND

There are roughly 14 million adults in the United States presenting with symptomatic osteoarthritis (OA) of the knee. Nerve radiofrequency ablation (RFA) is a nonsurgical procedure for the management of knee OA symptoms, and no previous systematic review has been performed comparing geniculate nerve RFA to other nonsurgical treatments.

QUESTIONS/PURPOSES

(1) How does geniculate nerve RFA compare with other nonsurgical modalities for patients with knee OA about pain, function, quality of life, and composite scores? and (2) How does geniculate nerve RFA compare with other nonsurgical modalities for patients with knee OA about adverse events (AEs)?

METHODS

A systematic literature review was conducted within PubMed, EMBASE, and Cochrane Central Register of Controlled Trials to identify all studies from 1966 to 2019 evaluating the relative effectiveness of geniculate nerve thermal (heated or cooled) RFA compared with other nonsurgical treatments for knee OA. Two independent abstractors reviewed and analyzed the literature including comparators such as intra-articular (IA) corticosteroids, IA hyaluronic acid, NSAIDs, acetaminophen (paracetamol), and control/sham procedures. Inclusion was based on the following criteria: English language, human subjects, symptomatic knee OA, and patient-reported outcomes.

RESULTS

Five high-quality and two moderate-quality randomized controlled trials (RCTs) met the inclusion criteria for this review. The results showed consistent agreement across all RCTs in favor of geniculate nerve thermal RFA use for nonsurgical treatment of knee OA. One high-quality RCT and one moderate-quality RCT found geniculate nerve RFA to provide statistically significant outcome improvement compared with control or sham procedures regarding pain, function, quality of life, and composite scores. When compared with IA corticosteroids and hyaluronic acid, geniculate nerve RFA also provided notable improvement in pain, function, and composite scores (visual analog scale, Western Ontario, and McMaster Universities Arthritis Index, and Oxford Knee Score). RFA was markedly favored for all pain and composite outcomes (Western Ontario and McMaster Universities Arthritis Index and visual analog scale). The included RCTs did not report any serious AEs related to geniculate nerve RFA.

DISCUSSION

These results demonstrate geniculate nerve thermal RFA to be a superior nonsurgical treatment of knee OA compared with NSAIDs and IA corticosteroid injections. None of the RCTs reported any serious AEs with geniculate nerve thermal RFA, as opposed to known cardiovascular, gastrointestinal, and renal AEs for NSAIDs and accelerated cartilage loss and periprosthetic infection risk for IA corticosteroid injections.

LEVEL OF EVIDENCE

Level I.

Radiofrequency ablation reduces pain for knee osteoarthritis: A meta-analysis of randomized controlled trials

BACKGROUND

Currently, there is poor evidence on the effect of radiofrequency ablation (RFA) on pain and knee function in patients with knee osteoarthritis (OA). We performed a meta-analysis on randomized controlled trials (RCTs) to determine the effectiveness and safety of RFA on pain and knee function in individuals with knee OA.

METHODS

PubMed, EMBASE, Web of Science, Cochrane, Ovid and MEDLINE were systematically searched (up to March 20, 2021) to obtain literature focusing on the impact of RFA on knee OA, using the following keywords and their synonyms: "radiofrequency ablation", "neurotomy", "knee" and "osteoarthritis". Two authors independently evaluated the quality of the RCTs according to the Cochrane Handbook for Systematic Reviews of Interventions version. Pooled effects of this meta-analysis were calculated using STATA version 13.0.

RESULTS

Eight RCTs were included for data extraction and meta-analysis. The present study indicated that there were significant differences between the two groups of patients who were treated or not treated with RFA on the pain intensity at 4 week (WMD = -0.504; 95% CI: 0.708 to -0.300; P < 0.001), 12 week (WMD = -0.280; 95% CI: 0.476 to -0.084; P = 0.005) and 24 week (WMD = -2.437; 95% CI: 4.742 to -0.132; P = 0.038). Furthermore, RFA was associated with improved outcome of the Western Ontario and McMaster Universities Arthritis index at 4 week (WMD = -3.189; 95% CI: 5.996 to -0.382, P = 0.026), 12 week (WMD = -3.706; 95% CI:-6.584 to -0.828, P = 0.012) and 24 week (WMD = -2.437; 95% CI: 4.742 to -0.132). No serious adverse events were observed in all patients who received RFA (RD = -0.019; 95% CI: 0.053 to 0.016; P = 0.294).

CONCLUSION

RFA showed better effectiveness in relieving pain and promoting function recovery in patients with knee OA. Considering the small sample size of the included studies, the results should be treated with caution.

Clinical and technical factors associated with knee radiofrequency ablation outcomes: a multicenter analysis

BACKGROUND

There has been a surge in interest in radiofrequency ablation (RFA) of the genicular nerves over the past decade, with wide variability in selection, technique and outcomes. The aim of this study is to determine factors associated with treatment outcome.

METHODS

We retrospectively evaluated the effect of 23 demographic, clinical and technical variables on outcomes in 265 patients who underwent genicular nerve RFA for knee pain at 2 civilian and 1 military hospital. A primary outcome was designated as a > 30% decrease in average knee pain score lasting at least 3 months without cointerventions.

RESULTS

The overall rate of a positive response was 61.1% (95% CI 55.2% to 67.0%). In univariable analysis, larger electrode size (p=0.01), repeated lesions (p=0.02), having>80% pain relief during the prognostic block (p=0.02), not being on opioids (p=0.04), having no coexisting psychiatric condition (p=0.02), having a lower baseline pain score (p=0.01) and having >3 nerves targeted (p=0.02) were associated with a positive outcome. In multivariate logistic analysis, being obese (OR 3.68, 95% CI 1.66 to 8.19, p=0.001), not using opioids (OR 0.35, 95% CI 0.16 to 0.77, p=0.009), not being depressed (OR 0.29, 95% CI 0.10 to 0.82, p=0.02), use of cooled RFA (OR 3.88, 95% CI 1.63 to 9.23, p=0.002) and performing multiple lesions at each neural target (OR 15.88, 95% CI 4.24 to 59.50, p<0.001) were associated with positive outcome.

CONCLUSIONS

We identified multiple clinical and technical factors associated with treatment outcome, which should be considered when selecting patients for RFA treatment and in the design of clinical trials.

Lower limb kinematics improvement after genicular nerve blockade in patients with knee osteoarthritis: a milestone study using inertial sensors

Background

Genicular nerve blockade is a possible treatment for patients with knee osteoarthritis. Pain relief and improvement in functioning is expected. This procedure could be of major interest for patients in low-income countries where total knee arthroplasty is not available for the population. This study aims at assessing the immediate benefits on pain, gait, and stairs kinematics after a genicular nerve blockade in patients suffering from knee osteoarthritis in Cameroun.

Methods

A prospective study was carried out on 26 subjects in Cameroun. A genicular nerve blockade was performed on 14 women with painful knee osteoarthritis grade 2–4. Lower limb joint angles were recorded with inertial sensors before and 1 h after injection. Patient-reported outcomes of pain and perceived difficulty were collected, as well as 10 m and 6 min walking tests. A reliability analysis of inertial sensors was performed on a sample of 12 healthy subjects by calculating the intraclass correlation coefficient and the standard error of measurement.

Results

Pain and perceived difficulty decreased significantly (p < 0.001). Cadence increased significantly in stairs climbing (upstairs: + 7.7 steps/min; downstairs: + 7.6 steps/min). There was an improvement for hip sagittal range of motion during gait (+ 9.3°) and pelvis transverse range of motion in walking upstairs (− 3.3°). Angular speed range of the knee in the sagittal plane and of the hip in the frontal plane increased significantly in stairs descent (+ 53.7°/s, + 94.5°/s).

Conclusions

This study quantified improvement of gait and stair climbing immediately after a genicular nerve blockade in patients suffering from knee OA in Cameroon. This is the first study objectifying this effect, through wearable sensors.

Trial registration

Pan African Clinical Trial Registry, PACTR202004822698484. Registered 28 March 2020 - Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03836-8.

A Review of Non-Surgical Pain Management in Osteoarthritis

Osteoarthritis is a prominent cause of disability in older adults, especially with an increasingly obese and aging population. Clinical management of pain secondary to osteoarthritis should focus on education and self-management with exercise and weight management as a priority. Surgical intervention should only be considered once conservative measures have failed. This review provides a clinical update on the pathogenesis, diagnosis, and management of osteoarthritis.

Physiological and functional responses of water-cooled versus traditional radiofrequency ablation of peripheral nerves in rats

BACKGROUND AND OBJECTIVES

Several clinical studies have focused on assessing the effectiveness of different radiofrequency ablation (RFA) modalities in pain management. While a direct head-to-head clinical study is needed, results from independent studies suggest that water-cooled RFA (CRFA) may result in longer lasting pain relief than traditional RFA (TRFA). The primary purpose of this study was, therefore, to investigate in a preclinical model, head-to-head differences between the two RFA technologies.

METHODS

RFA was performed in a rat sciatic nerve model (n=66) in two groups: (1) TRFA or (2) CRFA. The surgeon was not blinded to the treatment; however, all the physiological endpoints were assessed in a blinded fashion which include histological, MRI, and nerve function assessment via electromyography.

RESULTS

The energy delivered by the generator for CRFA was significantly higher compared with TRFA. Histological staining of nerves harvested immediately following CRFA exhibited extended length and multiple zones of thermal damage compared with TRFA-treated nerves. MRI scans across 4 weeks following treatment showed edematous/inflammatory zones present for longer times following CRFA. Finally, there was greater attenuation and prolonged loss of nerve function measured via electromyography in the CRFA group.

CONCLUSIONS

This study shows that CRFA has greater energy output, as well as more pronounced structural and functional changes elicited on the peripheral nerves compared with TRFA. While these preclinical data will need to be confirmed with a large clinical randomized controlled trial, we are encouraged by the direction that they may have set for those trials.

Ultrasound-guided cooled radiofrequency ablation of the genicular nerves: a technique paper

Aim: Cooled radiofrequency ablation (CRFA) has demonstrated efficacy in the management of knee pain caused by osteoarthritis. A typical procedure involves fluoroscopic placement of internally cooled radiofrequency probes to ensure the probes are located near target genicular nerves. Patients & methods: A new technique was developed to perform CRFA using ultrasound (US) guidance. Patient outcomes were reported using a telephone survey. Results: Ablation procedures were successfully performed using US guidance. A total of 51 patients were retrospectively identified for telephone screening. A total of 22 patients completed the telephone questionnaire. There were no safety concerns identified and the majority of patients reported satisfactory outcomes. Conclusion: Patient outcomes demonstrate that US-guided CRFA procedures provide pain relief and functional improvement. Further studies are needed to compare the efficacy of US-guided CRFA to fluoroscopy-guided CRFA procedures.

Results of genicular nerve ablation by radiofrequency in osteoarthritis-related chronic refractory knee pain

Background/aim

The aim of this study was to investigate the medium- to long-term effects of radiofrequency (RF) ablation of genicular nerves for chronic refractory knee pain due to osteoarthritis (OA).

Materials and methods

Forty-eight patients who underwent RF ablation of the genicular nerves were evaluated retrospectively. The visual analogue scale (VAS) score, Western Ontario and McMaster universities osteoarthritis index (WOMAC index), opioid and nonsteroidal antiinflammatory drug (NSAID) use score, quality of life score, and treatment satisfaction score were examined at 1, 3, and 6 months after the procedure.

Results

The mean VAS scores were significantly lower at the 1-, 3-, and 6-month evaluations compared with the preoperative values (P < 0.001). A significant decrease was observed in the WOMAC index compared with preoperative values (P < 0.001). It was found that 66.7% of opioid users and 56.3% of NSAID users stopped using medication. No serious complications were encountered during or after the procedure.

Conclusion

In chronic refractory knee pain due to OA, the application of RF ablation to the genicular nerve is an effective and safe treatment option in the medium to long term.

Radiofrequency Procedures for the Treatment of Symptomatic Knee Osteoarthritis: A Systematic Review

OBJECTIVE

To evaluate the effectiveness and safety of radiofrequency (RF) ablation and neuromodulation modalities for knee osteoarthritis (OA).

METHODS

The Pubmed, Medline, Embase, and Cochrane Library databases were searched from inception to August 2018. All comparative and noncomparative studies that reported clinical outcome measures and adverse events related to RF modalities for knee OA were included. Pain scores, physical function measures, quality of life (QOL), patient satisfaction, and adverse events for three months and beyond of postprocedure follow-up were analyzed qualitatively.

RESULTS

Thirty-three studies, including 13 randomized controlled trials (RCTs), two nonrandomized comparative studies, and 18 noncomparative cohort studies, were identified, with 1,512 patients (mean age = 64.3 years, 32.5% males). All 33 studies were considered to be of moderate or high methodological quality. All 33/33 (100%) studies reported alleviation of OA-related knee pain from baseline until three to 12 months with RF modalities, with six comparative studies reporting 194/296 (65.5%) and 29/150 (19.3%) RF and control patients achieving >50% pain relief, respectively. Three of the 33 studies reported QOL, with three of three studies (100%) achieving improvements in disease-specific QOL from baseline until three to 12 months. Twenty-eight of the 33 studies reported functional outcomes, with 27/28 (96%) studies obtaining enhanced functionality from baseline up until three to 12 months. Ten of the 33 studies reported patient satisfaction, with eight of 10 studies (80%) indicating that patients were significantly satisfied after RF procedures, and from these eight studies, four were comparative studies that indicated that 86/154 (56%) and 33/104 (32%) RF and control patients were extremely satisfied or satisfied, respectively. Regarding adverse events (AEs), 29 of the 33 studies reported AEs, with 20/29 (69%) studies indicating no AEs related to the RF modalities and the remaining nine studies only indicating minor localized AEs. Twenty-nine of the 33 studies indicated no serious knee-related AEs pertaining to RF modalities.

CONCLUSIONS

Current evidence substantiates that RF modalities for knee OA potentially improve pain, functionality, and disease-specific QOL for up to three to 12 months with minimal localized complications. This suggests that RF modalities are perhaps an effective adjunct therapy for patients with knee OA who are unresponsive to conservative therapies. Further RCTs with larger sample sizes and long-term follow-up that directly compare the three primary RF modalities are warranted to confirm the clinical efficaciousness and superiority of these RF modalities for knee OA.

Cooled Radiofrequency Ablation Treatment of the Genicular Nerves in the Treatment of Osteoarthritic Knee Pain: 18- and 24-Month Results

Objective

The primary objective of this observational, prospective, multicenter study was to evaluate the long‐term outcomes, including pain, function, and perceived effect of treatment, in subjects undergoing cooled radiofrequency ablation (CRFA) who have pain due to osteoarthritis (OA) of the knee.

Methods

This analysis included a subset of subjects previously enrolled in a prospective, multicenter randomized study comparing the safety and effectiveness of CRFA and intra‐articular steroid injection in patients with knee OA through 12 months who were contacted to participate in this extension study. Subjects were enrolled if they agreed to participate in up to 2 additional follow‐ups, at 18 and 24 months.

Results

Eighty‐three subjects from the 5 participating sites underwent CRFA during the original study and were contacted for this extension study. Of the 33 subjects enrolled, 25 were evaluated at 18 months after CRFA treatment, and their mean numeric rating scale (NRS) score was 3.1 ± 2.7, with 12 subjects reporting ≥50% pain relief compared to baseline. At 24 months, 18 subjects reported a mean NRS score of 3.6 ± 2.8, with 11 demonstrating ≥50% pain relief. Functional improvement as measured by the Oxford Knee Score continued to be present, with an overall mean change from baseline of 26.0 ± 9.6 points at 18 months and 29.9 ± 10.4 points at 24 months.

Conclusion

In this subset of subjects from a randomized controlled trial, CRFA provided sustained pain relief, improved function, and perceived positive effect through 24 months for subjects with OA knee pain with no safety concerns identified.

Review of Knee Joint Innervation: Implications for Diagnostic Blocks and Radiofrequency Ablation

Objective

To determine if commonly used knee radiofrequency ablation (RFA) techniques would be able to completely denervate the knee joint.

Methods

A comprehensive search of the literature on knee joint innervation was conducted using the databases Medline, Embase, and PubMed from inception through February 1, 2019. Google Scholar was also searched. Data on the origin, number of articular branches, course, distribution, and frequency of each nerve innervating the knee joint were extracted from the included studies and compared in order to identify variations.

Results

Twelve studies of anterior knee joint innervation and six studies of posterior knee joint innervation were included. The anterior knee joint was innervated by 10 nerves and further subdivided into two parts (anteromedial and anterolateral) or four quadrants (superomedial, inferomedial, superolateral, and inferolateral) based on innervation patterns; the posterior knee joint was innervated by two or three nerves, most commonly via the popliteal plexus. There is a lack of precise, validated anatomic targets identifiable with fluoroscopy and ultrasound for knee diagnostic blocks and RFA. Only three of the 12 or potentially 13 nerves innervating the knee joint are targeted by commonly used knee RFA techniques.

Conclusions

Commonly used knee RFA techniques would not be able to completely denervate the knee joint. It may not be necessary to capture all of the nerves, but only the nerves mediating a patient’s pain. Further clinical studies are required to validate specific diagnostic blocks and evaluate clinical outcomes using rigorous diagnostic blocks and anatomically specific knee RFA techniques.

Feasibility of an ultrasound-guided approach to radiofrequency ablation of the superolateral, superomedial and inferomedial genicular nerves: a cadaveric study

INTRODUCTION

Genicular nerve radiofrequency (RF)denervation appears to be a promising treatment for knee pain in patients with degenerative osteoarthritis of the knee, when candidates are not suitable for arthroplasty. This study aimed to assess the accuracy and reliability of ultrasound-guided placement of RF cannulas in cadavers for genicular nerve treatment, by measuringthe needle-to-nerve proximity.

MATERIALS AND METHODS

Five soft-fix human cadavers were included in this study, totaling 10 knees (meanage 93.8 years). Using the ultrasound-guided technique,which we have described previously, RF cannulas were directed toward the superolateral genicular nerve(SLGN), the superomedial genicular nerve (SMGN) and the inferomedial genicular nerve (IMGN). Indocyaninegreen (ICG) dye (0.1 mL) was infiltrated. An anatomical dissection was performed and the distance from the center of the ICG mark to the genicular nerve concerned was measured.

RESULTS

The mean distances from the center of the ICG mark to the SLGN, SMGN and IMGN were 2.33 mm(range 0.00-6.05 mm), 3.44 mm (range 0.00-10.59mm) and 1.32 mm (range 0.00-2.99 mm), respectively. There was no statistical difference in distances from the center of the ICG mark to the targeted nerve between the different nerves (p=0.18).

CONCLUSION

The results of this study demonstrate that ultrasound-guided treatment of the genicular nerves is feasible. However, for RF ablations, there are some limitations, which mostly can be overcome by using appropriate RF ablation settings.

Indications of the Neurotomy of Genicular Nerves by Radiofrequency for the Treatment of Knee Osteoarthritis: A Literature Review

Osteoarthritis (OA) is one of the most frequent and incapacitating pathologies today, especially of the knee. Among the possible approaches for knee OA, the neurotomy of the genicular nerves by radiofrequency (RF) has been gaining prominence. However, as this is a relatively new procedure, indications for its implementation are still unclear. The objective of the present review is to identify the main indications of the use of RF for the treatment of knee OA in the medical literature. A review of the literature was performed in January 2018 through a search in the PubMed, ClinicalKey and Google Scholar databases. After reviewing the main articles on the subject, it was concluded that the main indications of the use of RF for the treatment of knee OA were: OA Kellgren-Lawrence grades 3 and 4, with moderate to severe pain and failure of conservative treatment, mainly in elderly people; persistence of pain even after total knee arthroplasty (TKA); patients with an indication for TKA who refuse to undergo surgical treatment.

Can recent chronic pain techniques help with acute perioperative pain?

PURPOSE OF REVIEW

This article discussed how the knowledge and technique of a few chronic pain procedures benefited the perioperative clinicians in their care of patients receiving specific orthopaedic surgical procedures.

RECENT FINDINGS

Recent emerging interest in hip and knee denervation for chronic pain management secondary to osteoarthritis stimulates publications on the new understanding of hip and knee joint innervation. The improved understanding of the anatomy allows better precision in targeting the articular branches. The procedures for chronic joint pain such as radiofrequency ablation, chemical neurolysis and neuromodulation procedure have recently been applied to the perioperative care in orthopaedic procedures because of the potential long-lasting analgesia, opioid-sparing effect and consequent improvement in physical function and health-related quality of life after surgery.

SUMMARY

Despite the widespread use of regional anaesthesia and multimodal analgesia in the perioperative pain management, more than two-third of the patients reported severe postoperative pain. Therefore, other therapeutic strategies used in chronic pain management such as radiofrequency ablation and neuromodulation have been proposed to optimize acute postsurgical pain. The early experience with those techniques is encouraging, and more studies are required to explore the incorporation of these procedures in the perioperative care.

Cooled radiofrequency ablation of the genicular nerves for chronic pain due to osteoarthritis of the knee: a cost-effectiveness analysis based on trial data

BACKGROUND

For patients with painful knee osteoarthritis, long-term symptomatic relief may improve quality of life. Cooled radiofrequency ablation (CRFA) has demonstrated significant improvements in pain, physical function and health-related quality of life compared with conservative therapy with intra-articular steroid (IAS) injections. This study aimed to establish the cost-effectiveness of CRFA compared with IAS for managing moderate to severe osteoarthritis-related knee pain, from the US Medicare system perspective.

METHODS

We conducted a cost-effectiveness analysis utilizing efficacy data (Oxford Knee Scores) from a randomized, crossover trial on CRFA (NCT02343003), which compared CRFA with IAS out to 6 and 12 months, and with IAS patients who subsequently crossed over to receive CRFA after 6 months. Outcomes included health benefits (quality-adjusted life-years [QALYs]), costs and cost-effectiveness (expressed as cost per QALY gained). QALYs were estimated by mapping Oxford Knee Scores to the EQ-5D generic utility measure using a validated algorithm. Secondary analyses explored differences in the settings of care and procedures used in-trial versus real-world clinical practice.

RESULTS

CRFA resulted in an incremental QALY gain of 0.091 at an incremental cost of $1711, equating to a cost of US$18,773 per QALY gained over a 6-month time horizon versus IAS. Over a 12-month time horizon, the incremental QALY gain was 0.229 at the same incremental cost, equating to a cost of US$7462 per QALY gained versus IAS. Real-world cost assumptions resulted in modest increases in the cost per QALY gained to a maximum of US$21,166 and US$8296 at 6 and 12 months, respectively. Sensitivity analyses demonstrated that findings were robust to variations in efficacy and cost parameters.

CONCLUSIONS

CRFA is a highly cost-effective treatment option for patients with osteoarthritis-related knee pain, compared with the US$100,000/QALY threshold typically used in the US.