Knee Osteoartritis Genicular Nerve RF Ablation vs Alcohol Neurolysis

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.

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.

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).