Systematic Review of Radiofrequency Ablation for Management of Knee Pain

Efficacy of Cooled-Radiofrequency Ablation of the Genicular Nerve as Treatment for Chronic Knee Pain: A Retrospective Study

INTRODUCTION

Chronic pain is one of the leading causes of reduced quality of life in the USA, with knee pain commonly reported. Multiple therapeutic modalities are traditionally utilized for pain management; however, some patients may have pain refractory to these techniques. Cooled radiofrequency ablation (c-RFA) of the geniculate nerve is a growing and promising therapy offering a potentially long-term solution to chronic knee pain.

METHODS

This study assessed the efficacy, average duration of relief, and potential adverse events using a retrospective chart review of 406 procedures. A two-tailed paired t test was used to assess the statistical significance between pre-RFA vs. post-RFA visual analog scale (VAS) pain scores self-reported by patients. An analysis of variance (ANOVA) test was used to evaluate for statistical differences in pre-RFA pain scores and post-RFA pain scores among the categories of age, sex, body mass index (BMI), and diagnosis group.

RESULTS

The mean percent in pain improvement calculated was 65.5% with an average duration of relief of 7.20 months. The average pre-RFA pain score on the VAS was 6.26 out of 10 and 2.59 out of 10 post-RFA. The ANOVA post-RFA pain scores demonstrated statistically significant differences among the categories of age and sex. A total of 54 adverse events were reported, including worsening pain, numbness, paresthesia, and knee swelling.

CONCLUSION

The study demonstrated that c-RFA can potentially be utilized as an alternative safe therapy for chronic knee pain, providing pain relief with a relatively prolonged duration. Inherent challenges of retrospective studies remain a part of the limitations of this study.

Infrapatellar Branch of the Saphenous Nerve: Therapeutic Approaches to Chronic Knee Pain

PURPOSE OF REVIEW

The infrapatellar branch of the saphenous nerve (IPS) is an under-investigated nerve that can be a source of chronic knee pain. This literature review aims to deliver an up-to-date review of chronic pain transmitted via the IPS along with therapeutic approaches available for pain refractory to conservative measures.

RECENT FINDINGS

Knee pain transmitted via the IPS can arise from several etiologies. Damage to the IPS is often iatrogenic and develops following total knee arthroplasty, anterior cruciate ligament reconstruction, and other knee surgical procedures. Other causes of IPS-derived pain include entrapment of the nerve, neuromas, Schwannomas, and pain from knee osteoarthritis transmitted through the IPS.This article investigated therapeutic approaches to pain derived from the IPS. Common approaches included radiofrequency ablation, neuroma excisions, Schwannoma excision, nerve blocks, surgical exploration, surgical release of an entrapped nerve, cryoablation, and peripheral nerve stimulation. Pain scores, duration of pain relief, adverse events, and secondary outcomes were all included in this review. A subset of the patient population experiences chronic pain deriving from the IPS that is refractory to conservative treatment measures. This review aims to evaluate the etiologies and therapeutic approaches for chronic pain arising from the IPS refractory to conservative treatments.

The effects of radiofrequency electromagnetic fields exposure on tinnitus, migraine and non-specific symptoms in the general and working population: A systematic review and meta-analysis on human observational studies

BACKGROUND

Applications emitting radiofrequency electromagnetic fields (RF-EMF; 100 kHz to 300 GHz) are widely used for communication (e.g. mobile phones), in medicine (diathermy) and in industry (RF heaters).

OBJECTIVES

The objective is to systematically review the effects of longer-term or repeated local and whole human body radiofrequency electromagnetic field (RF-EMF) exposure on the occurrence of symptoms. Primary hypotheses were tinnitus, migraine and headaches in relation to RF-EMF exposure of the brain, sleep disturbances and composite symptom scores in relation to whole-body RF-EMF exposure.

METHODS

Eligibility criteria: We included case-control and prospective cohort studies in the general population or workers estimating local or whole-body RF-EMF exposure for at least one week.

INFORMATION SOURCES

We conducted a systematic literature search in various databases including Web of Science and Medline. Risk of bias: We used the Risk of Bias (RoB) tool developed by OHAT adapted to the topic of this review.

SYNTHESIS OF RESULTS

We synthesized studies using random effects meta-analysis.

RESULTS

Included studies: We included 13 papers from eight distinct cohort and one case-control studies with a total of 486,558 participants conducted exclusively in Europe. Tinnitus is addressed in three papers, migraine in one, headaches in six, sleep disturbances in five, and composite symptom scores in five papers. Only one study addressed occupational exposure.

SYNTHESIS OF RESULTS

For all five priority hypotheses, available research suggests that RF-EMF exposure below guideline values does not cause symptoms, but the evidence is very uncertain. The very low certainty evidence is due the low number of studies, possible risk of bias in some studies, inconsistencies, indirectness, and imprecision. In terms of non-priority hypotheses numerous exposure-outcome combinations were addressed in the 13 eligible papers without indication for an association related to a specific symptom or exposure source.

DISCUSSION

Limitations of evidence: This review topic includes various challenges related to confounding control and exposure assessment. Many of these aspects are inherently present and not easy to be solved in future research. Since near-field exposure from wireless communication devices is related to lifestyle, a particular challenge is to differentiate between potential biophysical effects and other potential effects from extensive use of wireless communication devices that may compete with healthy behaviour such as sleeping or physical activity. Future research needs novel and innovative methods to differentiate between these two hypothetical mechanisms.

INTERPRETATION

This is currently the best available evidence to underpin safety of RF-EMF. There is no indication that RF-EMF below guideline values causes symptoms. However, inherent limitations of the research results in substantial uncertainty.

OTHER

Funding: This review was partially funded by the WHO radioprotection programme.

REGISTRATION

The protocol for this review has been registered in Prospero (reg no CRD42021239432) and published in Environment International (Röösli et al., 2021).

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.

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.

[Interdisciplinary position paper: the value of radiofrequency denervation in the treatment of chronic pain]

Radiofrequency denervation has been established for many years as an important minimally invasive procedure for the treatment of chronic pain conditions. Positive experiences of many users for various indications are contrasted by a nonuniform evidence. With meticulous patient selection and correct assessment of the indications a longer term reduction of pain, a reduced need for analgesics and an improvement in the quality of life can be achieved. The aim of this interdisciplinary position paper is to present the value of radiofrequency denervation in the treatment of chronic pain. The summarized recommendations of the expert group are based on the available evidence and on the clinical experiences of Austrian centers that frequently implement the procedure. The position paper contains recommendations on patient selection and proven indications. We discribe safety aspects, complications, side effects and contraindications.

Domain Heterogeneity in Radiofrequency Therapies for Pain Relief: A Computational Study with Coupled Models

The objective of the current research work is to study the differences between the predicted ablation volume in homogeneous and heterogeneous models of typical radiofrequency (RF) procedures for pain relief. A three-dimensional computational domain comprising of the realistic anatomy of the target tissue was considered in the present study. A comparative analysis was conducted for three different scenarios: (a) a completely homogeneous domain comprising of only muscle tissue, (b) a heterogeneous domain comprising of nerve and muscle tissues, and (c) a heterogeneous domain comprising of bone, nerve and muscle tissues. Finite-element-based simulations were performed to compute the temperature and electrical field distribution during conventional RF procedures for treating pain, and exemplified here for the continuous case. The predicted results reveal that the consideration of heterogeneity within the computational domain results in distorted electric field distribution and leads to a significant reduction in the attained ablation volume during the continuous RF application for pain relief. The findings of this study could provide first-hand quantitative information to clinical practitioners about the impact of such heterogeneities on the efficacy of RF procedures, thereby assisting them in developing standardized optimal protocols for different cases of interest.