Knee Osteoartritis Genicular Nerve RF Ablation vs Alcohol Neurolysis (GEN-AL-RF)

Comparison of Genicular Nerve Radiofrequency Ablation and Neurolytic Alcohol Injection for Chronic Knee Osteoarthritis Pain: A Randomized Controlled Trial

The GEN-AL-RF study is a randomized controlled trial designed to compare the clinical efficacy of two interventional techniques for managing chronic knee pain due to osteoarthritis. The study focuses on genicular nerve radiofrequency (RF) ablation versus neurolytic alcohol injection for pain blockade.

Patients diagnosed with knee osteoarthritis are randomly assigned to either the RF ablation group or the neurolytic alcohol group. The primary objective is to evaluate the superiority and duration of analgesic effects between these two methods. Clinical outcomes are assessed at baseline and at 1, 3, and 6 months post-procedure using the Numeric Rating Scale (NRS) for pain intensity, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for physical function, and the Short Form-12 (SF-12) for health-related quality of life.

The results of this study aim to provide high-quality evidence regarding the comparative effectiveness and long-term outcomes of genicular nerve RF and alcohol neurolysis in the clinical management of chronic knee osteoarthritis pain.

Study Overview

• Status: Not yet recruiting
• Conditions: Radiofrequency Ablation; Knee Osteoarthristis; NEUROLYSIS
• Intervention / Treatment: Other: genicular nerve block

Detailed Description

The GEN-AL-RF study investigates the clinical outcomes of two ultrasound-guided genicular nerve procedures in patients with Grade 3-4 knee osteoarthritis according to Kellgren-Lawrence criteria. Patients who have failed conservative treatment options are enrolled and randomly assigned to one of two intervention groups.

Under real-time ultrasound guidance, the superior medial, superior lateral, and inferior medial genicular nerves are targeted. In the Thermal Radiofrequency (RF) group, patients receive RF ablation at 75°C for 90 seconds per target nerve. In the Neurolytic Alcohol group, 1 mL of absolute ethanol is injected at each of the three anatomical targets. Both procedures are performed by experienced physicians using standardized needle placement techniques.

Clinical assessments are conducted at baseline and at follow-up intervals of 1, 3, and 6 months. The primary outcome is pain intensity measured by the Numeric Rating Scale (NRS). Secondary outcomes include physical function measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and health-related quality of life measured by the Short Form-12 (SF-12) survey. Safety is monitored throughout the study period by documenting any procedure-related adverse events.

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: murat erten; Phone Number: +905435118202; Email: muraterten37@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age: Patients aged 45 to 85 years.
• Diagnosis: Chronic knee pain for at least 6 months diagnosed with knee osteoarthritis according to American College of Rheumatology (ACR) criteria.
• Radiological Grade: Grade 3 or 4 according to the Kellgren-Lawrence (K-L) classification.
• Pain Severity: Baseline Numerical Rating Scale (NRS) score of 5 or higher.
• Failure of Conservative Treatment: Inadequate response to conservative treatments (e.g., physical therapy, NSAIDs, or intra-articular injections) for at least 3 months.
• Positive Diagnostic Block: At least 50% reduction in pain for minimum 24 hours following a prognostic genicular nerve block with local anesthetic.

Exclusion Criteria:

• Previous Surgery: History of knee arthroplasty or major knee surgery on the affected side.
• Specific Conditions: Presence of inflammatory arthritis (e.g., rheumatoid arthritis), gouty arthritis, or active infection at the injection site.
• Neurological Deficit: Severe neurological or psychiatric disorders that may interfere with pain assessment.
• Coagulopathy: Uncontrolled bleeding disorders or use of anticoagulant therapy that cannot be temporarily discontinued.
• Recent Injections: Intra-articular steroid or hyaluronic acid injection within the last 3 months.
• Allergy: Known allergy to local anesthetics, contrast agents, or ethyl alcohol.
• Pacemaker: Presence of a cardiac pacemaker or implanted electronic device (specifically for the RFA group).

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Genicular Nerve Thermal Radiofrequency Ablation; Patients in this group will receive conventional thermal radiofrequency ablation of the superior medial, superior lateral, and inferior medial genicular nerves. The procedure will be performed at 80°C for 90 seconds per site under ultrasound guidance to achieve thermal neurocoagulation.	Other: genicular nerve block; Genicular nerve radiofrequency ablation : Patients will undergo ultrasound or fluoroscopy-guided radiofrequency ablation of the genicular nerves (superior medial, superior lateral, and inferior medial). The procedure involves placing RF cannulas at the target neural sites. Once the position is confirmed by sensory and motor stimulation, thermal radiofrequency lesioning will be performed to disrupt pain signal transmission. Genicular nerve chemichal neurolysis: Patients will receive ultrasound or fluoroscopy-guided chemical neurolysis of the genicular nerves (superior medial, superior lateral, and inferior medial). Following correct needle placement confirmed by contrast spread or local anesthetic test block, a specific volume (1 mL per nerve) of ethyl alcohol (95-96% concentration) will be injected to achieve long-term neurolytic blockade of the target nerves.; Other Names: genicular nerve chemical neurolysis; genicular nerve radiofrequency ablation
Experimental: Genicular Nerve Chemical Neurolysis (Alcohol); Patients will receive chemical neurolysis of the superior medial, superior lateral, and inferior medial genicular nerves. 95% ethyl alcohol (1mL per site) will be injected at the target locations to achieve chemical neurodestruction of the sensory nerves.	Other: genicular nerve block; Genicular nerve radiofrequency ablation : Patients will undergo ultrasound or fluoroscopy-guided radiofrequency ablation of the genicular nerves (superior medial, superior lateral, and inferior medial). The procedure involves placing RF cannulas at the target neural sites. Once the position is confirmed by sensory and motor stimulation, thermal radiofrequency lesioning will be performed to disrupt pain signal transmission. Genicular nerve chemichal neurolysis: Patients will receive ultrasound or fluoroscopy-guided chemical neurolysis of the genicular nerves (superior medial, superior lateral, and inferior medial). Following correct needle placement confirmed by contrast spread or local anesthetic test block, a specific volume (1 mL per nerve) of ethyl alcohol (95-96% concentration) will be injected to achieve long-term neurolytic blockade of the target nerves.; Other Names: genicular nerve chemical neurolysis; genicular nerve radiofrequency ablation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline in Numeric Rating Scale (NRS) Score at 6 Months.	The Numeric Rating Scale (NRS) is a segmented numerical version of the visual analog scale in which a respondent selects a whole number (0-10 integers) that best reflects the intensity of their pain. The score ranges from 0 (no pain) to 10 (worst possible pain). A decrease in score indicates pain relief.	1 month, 3 months, and 6 months.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Score	The WOMAC is a proprietary set of standardized questionnaires used to evaluate the condition of patients with osteoarthritis of the knee and hip, including segments for pain, stiffness, and physical function. Higher scores indicate worse outcomes.	1 month, 3 months, and 6 months post-procedure.
Change from Baseline in 12-Item Short Form Health Survey (SF-12) Score.	The SF-12 is a self-reported outcome measure assessing health-related quality of life. It yields two summary scores: the Physical Component Summary (PCS) and the Mental Component Summary (MCS). Higher scores indicate better physical and mental health.	1 month, 3 months, and 6 months post-procedure

Collaborators and Investigators

• Sponsor: Sakarya University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 30, 2026

Study Registration Dates

• First Submitted: April 10, 2026
• First Submitted That Met QC Criteria: April 10, 2026
• First Posted (Actual): April 17, 2026

Study Record Updates

• Last Update Posted (Actual): April 17, 2026
• Last Update Submitted That Met QC Criteria: April 10, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: E.567659-139

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No