Phenol Neurolysis of Genicular Nerves for Osteoarthritic Knee Pain

As the aging and obese populations continue to increase, there is a rapidly growing number of people at risk for knee osteoarthritis. Treatment typically starts conservatively with analgesics, physical therapy, and bracing. Intra-articular injections with corticosteroids and/or viscosupplementation may also be utilized in those with persistent knee pain. Genicular nerve radiofrequency ablation (GNRFA) is an increasingly employed procedure for refractory osteoarthritic knee pain with promising efficacy for pain relief. However, due to its reliance on expensive equipment, additional staff, and need for specialized rooms (eg. fluoroscopy suite), GNRFA is a costly procedure with limited availability. Chemical neurolysis is an alternative method of nerve ablation using alcohol or phenol utilized in the management of pain. Recent literature has demonstrated good efficacy for pain relief and function with chemical ablation of the genicular nerves using both alcohol and phenol.

This study is a double-blind, randomized, placebo-controlled pilot study to assess the efficacy of phenol neurolysis of the genicular nerves for pain and function due to refractory osteoarthritic knee pain. We hypothesize that a significant improvement in both pain and function will be observed with chemical neurolysis of the genicular nerves using 6% phenol compared to placebo.

Study Overview

• Status: Recruiting
• Conditions: Osteoarthritis, Knee; Knee Pain Chronic
• Intervention / Treatment: Drug: 6% aqueous phenol; Drug: Isotonic saline

• Study Type: Interventional
• Enrollment (Anticipated): 30
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Paul So, MD; Phone Number: 973-972-3606; Email: ibaool@gmail.com

Study Locations

• United States
  • New Jersey
    • West Orange, New Jersey, United States, 07052
      • Recruiting
      • Kessler Institute for Rehabilitation
      • Contact: Paul So, MD
      • Sub-Investigator: Matthew Delbert, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Radiographic knee osteoarthritis (Kellgren-Lawrence grade 2-4)
• Knee pain of moderate intensity or greater (NRS of 4 or greater)
• Knee pain for 3 months or longer
• Persistent knee pain despite conservative treatment including oral/topical analgesics, physiotherapy, intra-articular injection with corticosteroid and/or hyaluronic acid

Exclusion Criteria:

• Prior total or partial knee arthroplasty in the knee(s) to be treated
• Prior radiofrequency ablation treatment in the affected knee
• Other rheumatological or connective tissue disease(s) affecting the knee to be treated
• History of bleeding disorder
• Any psychiatric or neurologic disease (eg. dementia, brain injury, etc.) that may preclude reliable reporting of symptoms and response to treatment
• Pregnancy
• Recent treatment with intraarticular hyaluronic acid, platelet-rich plasma, or corticosteroid injections to the affected knee in the past 3 months
• Skin or joint infection in the knee(s) to be treated
• Concomitant radicular pain

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment Group; 6% aqueous phenol, 1.5 mL per target site	Drug: 6% aqueous phenol; 1.5 mL of 6% aqueous phenol will be injected at each target genicular nerve under ultrasound guidance.; Other Names: Phenol
Placebo Comparator: Placebo Group; Isotonic saline, 1.5 mL per target site	Drug: Isotonic saline; 1.5 mL of isotonic saline will be injected at each target genicular nerve under ultrasound guidance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in NRS pain score from baseline	Participants' pain will be measured using the numeric rating scale (0-10) prior to the intervention and at 1 month, 3 months, and 6 months after the intervention. Numeric rating scale ranges from 0 (no pain) to 10 (worst pain).	Baseline, 1 month, 3 months, 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in WOMAC score from baseline	Participants' function as measured by WOMAC will be measured prior to the intervention and at 1 month, 3 months, and 6 months after the intervention. WOMAC score ranges from 0 (best) to 100 (worst).	Baseline, 1 month, 3 months, 6 months

Collaborators and Investigators

• Sponsor: Kessler Foundation
• Investigators: Principal Investigator: Paul So, MD, Kessler Institute for Rehabilitation

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2021
• Primary Completion (Anticipated): August 1, 2023
• Study Completion (Anticipated): October 1, 2023

Study Registration Dates

• First Submitted: July 27, 2021
• First Submitted That Met QC Criteria: July 27, 2021
• First Posted (Actual): August 4, 2021

Study Record Updates

• Last Update Posted (Actual): March 31, 2022
• Last Update Submitted That Met QC Criteria: March 30, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Osteoarthritis, Knee; Anti-Infective Agents, Local; Anti-Infective Agents; Pharmaceutical Solutions; Disinfectants; Sclerosing Solutions; Phenol
• Other Study ID Numbers: R-1154-21

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No