The Effectiveness of Fluoroscopically Guided Genicular Nerve Radiofrequency Ablation for the Treatment of Chronic Knee Pain Due to Osteoarthritis: A Systematic Review

Efficacy and Safety of Cryoablation Compared with Cooled Radiofrequency Ablation of Genicular Nerves in Advanced Osteoarthritis of the Knee: A Study Protocol of Single-Centric, Assessor-Blinded, Randomized, Parallel-Group, Non-inferiority Study

PURPOSE

In patients with symptomatic osteoarthritis knee (OAK), cryoneurolysis (CRYO) and cooled radiofrequency ablation (C-RFA) are reported to be effective and safe; however, they have not been compared directly. The objective of this study is to compare CRYO and C-RFA of the genicular nerve (GN) in terms of efficacy and safety profile in patients with Kellgren and Lawrence (KL) grade ≥ 3 OAK.

METHODS

This single-centric, assessor-blinded, randomized, parallel-group, non-inferiority study will include 80 patients with KL grade ≥ 3 OAK. The patients with ≥ 50% pain relief on diagnostic block of three GNs will be randomized to one of the two groups, i.e., CRYO (n = 40) or C-RFA (n = 40). The three target GNs for the interventions will include: superior medial, superior lateral, and inferior medial. The primary outcome will be efficacy of CRYO or C-RFA at 2, 12, and 24 weeks post-procedure based on the 11-point Numerical Pain Rating Scale. The secondary outcomes will be functional improvement based on 12-item Oxford Knee Score and safety of both the procedures. The study is registered in the Clinical Trials Registry-India.

CONCLUSION

CRYO and C-RFA provide pain relief and improve functional outcome by preventing transmission of pain signals, though by distinct mechanisms. While C-RFA is an established treatment modality, recent evidence supports CRYO in patients with OAK. This study intends to demonstrate non-inferiority of CRYO against C-RFA, thereby supporting the use of CRYO as an additional treatment modality in patients with KL grade ≥ 3 OAK.

Complications and opioid-prescribing patterns following genicular nerve radiofrequency ablation versus intra-articular injection: a matched cohort study

BACKGROUND AND OBJECTIVES

Genicular nerve radiofrequency ablation (GNRFA) is an emerging procedure used to relieve pain from severe knee osteoarthritis. While there have been rare reports of significant complications, their incidence has not been well established. The objective of this study was to examine complication rates at 30 and 90 days post treatment as well as characterize opioid-prescribing patterns before and after treatment.

METHODS

A large national database was queried to identify patients undergoing GNRFA from 2015 to 2022 and matched to control cohorts composed of patients receiving either intra-articular corticosteroid (CSI) or hyaluronic acid injection (HAI) of the knee. Complication rates at 30 and 90 days were analyzed. Opioid utilization was assessed in the 6 months before and after treatment.

RESULTS

Rates of infection (0.1%, CI 0.02% to 0.5% vs 0.2%, CI 0.05% to 0.6%), septic arthritis (<0.1%, CI 0.003% to 0.4% vs 0.1%, CI 0.02% to 0.5%), deep vein thrombosis (2.0%, CI 1.3% to 2.7% vs 1.6%, CI 1.0% to 2.2%), pulmonary embolism (1.2%, CI 0.6% to 1.7% vs 1.3%, CI 1.1% to 2.5%), bleeding (<0.1%, CI 0.003% to 0.4% vs 0%, CI 0% to 0.3%), seroma (<0.1%, CI 0.003% to 0.4% vs 0.2%, CI 0.05% to 0.6%), nerve injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%) and thermal injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%) were not different between CSI and GNRFA cohorts at 30 days. Rate of swelling was significantly greater in the GNRFA cohort (9.4%, CI 7.6% to 10.4% vs 6.4%, CI 4.8% to 7.2%, p=0.003) at 30 days. At 90 days, rates of septic arthritis (0.1%, CI 0.02% to 0.5% vs 0.3%, CI 0.08% to 0.7%), deep vein thrombosis (3.1%, CI 2.1% to 3.8% vs 3.1%, CI 2.2% to 3.9%), pulmonary embolism (1.5%, CI 0.9% to 2.1% vs 1.8%, CI 1.2% to 2.5%), and nerve injury (0%, CI 0% to 0.3% vs <0.1%, CI 0.003% to 0.4%) were not significantly different.Between HAI versus GNRFA cohorts, no significant differences were seen in rates of infection (0.3%, CI 0.08% to 0.07% vs 0.7%, CI 0.3% to 1.2%), septic arthritis (0.2%, CI 0.05% to 0.6% vs 0.4%, CI 0.2% to 0.9%), deep vein thrombosis (2.0%, CI 1.3% to 2.7% vs 1.9%, CI 1.2% to 2.7%), pulmonary embolism (1.5%, CI 0.9% to 2.2% vs 1.7%, CI 1.1% to 2.5%), bleeding (0.1%, CI 0.02% to 0.5% vs 0.2%, CI 0.05% to 0.6%), seroma (<0.1%, CI 0.03% to 0.4% vs 0%, CI 0% to 0.3%), nerve injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%), swelling (14.0%, CI 11.6% to 15.1% vs 12.0%, CI 10.3% to 13.6%), and thermal injury (<0.1%, CI 0.03% to 0.4% vs <0.01%, CI 0.3% to 0.4%) at 30 days. Rates of infection (0.7%, CI 0.3% to 1.2% vs 1.4%, CI 0.9% to 2.1%), septic arthritis (0.3%, CI 0.1% to 0.8% vs 0.5%, CI 0.2% to 1.1%), deep vein thrombosis (3.6%, CI 2.6% to 4.4% vs 3.1%, CI 2.2% to 4.0%), pulmonary embolism (2.3%, CI 1.5% to 3.0% vs 2.1%, CI 1.4% to 3.0%) and nerve injury (0%, CI 0% to 0.3% vs 0.1%, CI 0.02% to 0.5%) were not significantly different at 90 days.There were no significant differences in level of pretreatment opioid utilization although overall consumption in mean daily morphine equivalents was greater in the GNRFA cohort. Opioid utilization significantly increased in the first 30 days after ablation in patients with no prior opioid use compared to controls. In patients with some and chronic prior opioid use, opioid requirements were generally decreased in all treatment groups at 6 months with no clearly superior treatment in reducing opioid consumption.

CONCLUSION

Our study demonstrated that GNRFA possesses a safety profile similar to that of intra-articular injections although significant adverse events such as venous thromboembolism and septic arthritis may occur rarely. Although opioid utilization generally increased in the 30 days after ablation compared with intra-articular injection, similar reduction in opioid consumption at 6 months was seen in patients with prior opioid use in the ablation and control cohorts.

Bipolar radiofrequency ablation of genicular nerves in chronic knee pain: A novel technique for more complete sensory denervation

BACKGROUND

Monopolar radiofrequency ablation (MRFA) of the genicular nerves has been considered the main interventional treatment for chronic knee pain. However, the variable locations of these nerves could suggest that traditional MRFA of genicular nerves may be insufficient to cover the area needed to provide complete sensory denervation. For these reasons, some alternatives have been proposed to achieve an increase in the lesion area that offers better outcomes such a bipolar radiofrequency ablation (BRFA).

OBJECTIVE

To describe the efficacy and safety of the bipolar radiofrequency ablation (BRFA) of the genicular nerves in the patients with chronic knee pain.

METHODS

A retrospective study was conducted in the Pain Medicine Department. Institutional review board approval from the Hospital Ethical Committee and informed consent were obtained. We reviewed our database for BRFA of genicular nerves from January 2018 to December 2021 for patients with chronic knee pain. The cannulas were placed using ultrasound guidance (10 cm, 22-gauge and 10 mm active curved tip), and each pair of cannulas were subjected to BRFA for 90 seconds at 80∘C. Data analysis was conducted using T-test for paired variables (Visual analogue scale and EuroQol, an instrument intended to complement other forms of quality-of-life measures).

RESULTS

Twenty-five patients met inclusion criteria after excluding 7 based on the study design. The mean improvement of our patients according to the VAS was -3.98 (95%CI: -4.37 to -3.59) p< 0.0001 and EuroQol +0.416 (95%CI: 0.364 to 0.468) p< 0.0001. The mean duration of improvement was 8 (6-11) months after BRFA. There were no reported serious adverse events related to the procedure, only local pain for 24 to 48 hours in 3 patients.

CONCLUSIONS

We can conclude that BRFA reduces procedural pain and increases the treatment area, providing more complete sensory denervation and improved clinical outcomes.

Genicular nerve radiofrequency ablation for the treatment of chronic knee joint pain: a real-world cohort study with evaluation of prognostic factors

BACKGROUND

Genicular nerve radiofrequency ablation (GNRFA) is an effective treatment for chronic knee pain. However, there has been minimal investigation of real-world, long-term outcomes and factors that predict treatment success after GNRFA.

OBJECTIVES

To evaluate the effectiveness of GNRFA for chronic knee pain in a real-world population and identify predictive factors.

METHODS

Consecutive patients who underwent GNRFA at a tertiary academic center were identified. Demographic, clinical, and procedural characteristics were collected from the medical record. Outcome data were numeric rating scale (NRS) pain reduction and Patient Global Impression of Change (PGIC). Data were collected by standardized telephone survey. Predictors of success were evaluated with logistic and Poisson regression analyses.

RESULTS

Of the 226 total patients identified, 134 (65.6 ± 12.7; 59.7% female) were successfully contacted and analyzed, with a mean follow-up time of 23.3 ± 11.0 months. Of those, 47.8% (n = 64; 95% CI: 39.5%-56.2%) and 61.2% (n = 82; 95% CI: 52.7%-69.0%) reported ≥50% NRS score reduction and ≥2-point NRS score reduction, respectively, and 59.0% (n = 79; 95% CI: 50.5%-66.9%) reported "much improved" on the PGIC questionnaire. Factors associated with a greater likelihood of treatment success (P < .05) were higher Kellgren-Lawrence osteoarthritis grade (2-4 vs 0-1); no baseline opioid, antidepressant, or anxiolytic medication use; and >3 nerves targeted.

CONCLUSION

In this real-world cohort, approximately half of the participants experienced clinically meaningful improvements in knee pain after GNRFA at an average follow-up time of nearly 2 years. Factors associated with higher likelihood of treatment success were more advanced osteoarthritis (Kellgren-Lawrence Grade 2-4); no opioid, antidepressant, or anxiolytic medication use; and >3 nerves targeted.

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.

Neurological pain relief interventional radiology procedures

Neurological interventions have taken on a significant role in interventional radiology (IR) practice. Indications fall under three main categories: (1) intraprocedural pain management, (2) cancer pain palliation, and (3) chronic non-cancer pain control. Short-term regional anaesthesia can be achieved with local anaesthetics, while longer-term pain control can be attained with radiofrequency neuromodulation (pulsed or otherwise) or thermal/chemical neurolysis. This review article summarises the therapeutic options, applications, and techniques of commonly used peripheral nerve and plexus interventions in IR.

Genicular nerve and fracture site chemical neurolysis for distal femoral fracture: a case report

BACKGROUND

Distal femur fractures account for approximately 3%-6% of all femoral fractures. Non-operative management may be an attractive option for the elderly with significant perioperative mortality risk. Adequate pain control is a major barrier to non-operative fracture management. Chemical neurolysis has been described for analgesic management of proximal hip fractures, however no description of interventional management of distal femur fracture exists in literature. We describe a case of phenol chemical neurolysis of genicular nerves in addition to injection at the site of fracture to provide effective analgesia for distal femur fracture.

CASE PRESENTATION

A patient in their 90s with a witnessed mechanical fall sustained an intra-articular displaced fracture of the distal right femur shaft with extension into the distal femoral condyle. The patient elected to undergo non-surgical management given the high perioperative mortality risk. Acute pain service was involved and multimodal oral analgesics including opioids were insufficient in managing the patient's pain. The addition of femoral nerve catheter local anesthetic infusion did not sufficiently improve analgesia. Phenol chemical neurolysis of the superolateral, superomedial, inferomedial genicular nerves and of the fracture site was offered and performed. Resting pain decreased from Numerical Rating Scale 5/10 to 0/10 on postprocedure day 1. This was sustained at the 2-month timepoint.

CONCLUSIONS

We report the successful use of phenol neurolysis of genicular nerves and the fracture site in an elderly patient with a conservatively managed distal femur fracture. These interventions resulted in improved analgesia and achieved prolonged duration of effect.

Radiofrequency Ablation of the Infrapatellar Branch of the Saphenous Nerve for the Treatment of Chronic Anterior Inferomedial Knee Pain

INTRO

Genicular nerve radiofrequency ablation (GNRFA) is an effective treatment for chronic knee pain related to osteoarthritis. It is often utilized when conservative management has failed and patients wish to avoid arthroplasty, are poor surgical candidates due to comorbid medical conditions, or in those suffering from persistent pain after arthroplasty. The classic targets for GNRFA include the superior lateral genicular nerve, superior medial genicular nerve, and inferior medial genicular nerve but multiple anatomic studies have demonstrated additional sensory innervation to the knee.

OBJECTIVE

In this research article, we propose an image-guided technique that can safely target the infrapatellar branch of the saphenous nerve which also provides sensory innervation to the anterior capsule.

PROPOSAL

The proposed technique includes variations for conventional bipolar radiofrequency ablation, cooled radiofrequency ablation, dual-tined bipolar radiofrequency ablation, and monopolar radiofrequency ablation using a long axis approach. The described technique is based on updated anatomic studies and takes into account safety concerns such as thermal risk to the skin and/or pes anserine tendons and breaching of the synovial cavity.

CONCLUSION

Future clinical research should be performed to confirm the safety and effectiveness of this specific approach.