Comparison Between Ultrasound-Guided Genicular Nerve Phenol Neurolysis and Intra-articular Steroid Injections

Study Overview
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Brief Summary
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Genicular nerve neurolysis (GN) constitutes a relatively novel technique, whereby different chemical compounds (i.e. alcohol, phenol) are injected in close proximity to the genicular nerves of the knee joint, with the intention to exert a neurolytic effect by denaturing proteins resulting in Wallerian degeneration distal to the lesion. Based on the preliminary evidence and considering the potential benefits of the technique, we hypothesized that ultrasound-guided genicular chemical neurolysis with phenol is superior in terms of pain relief at 3 months, when compared to intra-articular steroid (IAS) injection.

Detailed Description
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This study will allow us to determine if ultrasound-guided phenol genicular neurolys is superior to intra-articular steroid injection in terms of analgesia and functional outcomes, providing a more effective and long-lasting alternative for patients with chronic knee pain secondary to osteoarthritis

Official Title
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Randomized, Double-blinded, Comparison Between Ultrasound-Guided Genicular Nerve Phenol Neurolysis and Intra-articular Steroid Injections

Conditions
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Osteoarthritis, Knee, Chronic Knee Pain

Intervention / Treatment
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* Drug: 6% aqueous phenol
* Drug: MethylPREDNISolone 40 MG
* Drug: Intraarticular Knee Placebo
* Drug: Genicular Nerve Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Severe knee pain for more than 6 months, defined as Numeric rating scale (NRS) score of 6 and greater, unresponsive to conservative medical treatment Radiological OA grade 2 to 4 (Kellgren-Lawrence scale) Exclusion Criteria: Previous total knee replacement on the index knee Prior knee radiofrequency ablation on the index knee Connective tissue diseases with knee involvement (e.g. rheumatoid arthritis) Body mass index ≥ 40 kg/m2 Uncontrolled coagulopathy, defined as supratherapeutic dose of anticoagulation medication Allergy to local anesthetics Unstable opioid consumption, defined as an increase >10% in dosage during the last 3 months prior to recruitment.

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ultrasound-guided Genicular Nerve Phenol Neurolysis<br>One time injection of 1.5 mL of phenol 6% at 3 target locations: superomedial, superolateral and inferomedial genicular nerves | Drug: 6% aqueous phenol<br>* 1.5 mL of aqueous phenol will be injected at each target genicular nerve under ultrasound guidance<br>Drug: Intraarticular Knee Placebo<br>* Single injection 1.5 mL of 0.9% normal saline outside the knee joint capsule under ultrasound guidance<br>* Other names: 0.9% normal saline;|
| Active Comparator: Ultrasound-guided Intraarticular Steroid Injection<br>Intraarticular knee injection of 40 mg of methylprednisolone acetate in a volume of 5 mL of saline | Drug: MethylPREDNISolone 40 MG<br>* 40 mg of methylprednisolone diluted in 5 mL of 0.9% normal saline will be injected inside the knee joint capsule under ultrasound guidance<br>Drug: Genicular Nerve Placebo<br>* 1.5 mL of 0.9% normal saline will be injected subcutaneously at each target genicular nerve under ultrasound guidance<br>* Other names: 0.9% normal saline;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain scores (Numeric Rating Scale) at 3 months | Knee pain intensity using Numeric Rating Scale ranging from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain scores (Numeric Rating Scale) at baseline, 1 and 6 months | Knee pain intensity using Numeric Rating Scale ranging from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | baseline, 1 month, 6 months | 
| Proportion of patients experiencing a 50% or greater decrease in baseline knee pain scores (NRS) | Knee pain intensity using Numeric Rating Scale ranging from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 1 months, 3 months, 6 months | 
| Brief Pain Inventory Score (BPI) | Functional activity measurement using the Brief Pain Inventory (short form) | baseline, 1 month, 3 months, 6 months | 
| WOMAC index | The WOMAC index consists of three subscales: pain, stiffness, and physical function (17 questions overall) | baseline, 1 month, 3 months, 6 months | 
| Incidence of adverse events | Determined by the presence of hypoesthesia, paresthesia, puncture site hematoma, and worsening pain or infection | from injection up to 1 month after intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Phenol, Injections, Intra-Articular, Steroids, Nerve Block