Unipolar Versus Bipolar Radiofrequency Ablation in Knee Osteoarthritis Pain

Osteoarthritis (OA) is one of the most common underlying causes of chronic knee pain resulting in loss of ability. Chronic knee pain due to OA is a debilitating disease. Many therapeutic options have been used to manage this pain such as physical therapy, non-steroid anti-inflammatory drugs (NSAIDs), tramadol, opioids, intraarticular hyaluronic acid, and steroids.

Radiofrequency ablation (RFA) appears to be effective for treatment of knee pain. It acts by interrupting the pain conduction through production of a thermal lesion to interrupt nociceptive signals.

A diagnostic genicular nerve block with local anesthetic is performed before genicular nerve RFA, and a positive result indicates the need for genicular RFA In conventional monopolar RFA (MRFA) technique, the localization of genicular nerves is one through sensory stimulation at the junction of epicondyle with the shaft of femur bone (near periosteum).

Inclusion criteria

• Age > 50 years.
• Both genders.
• Diagnosed with chronic knee osteoarthritis (KOA) according to the American College of Rheumatology (ACR) criteria and confirmed with plain radiography as the gold standard for the diagnosis of KOA.
• One chronic KOA pain not responding to other treatments as physiotherapy, oral analgesics, and intraarticular injection with hyaluronic acids or steroids.
• Kellgren-Lawrence grade (II-IV).

Exclusion criteria

• Chronic knee pain induced by infection, inflammation, tumors, and fractures.
• Prior knee surgery.
• Acute knee pain.
• Connective tissue diseases.
• Neurologic or psychiatric disorders.
• Intra-articular knee corticosteroid or hyaluronic acids in the past 3 months.
• Anticoagulant medication.
• Local infection of the site of intervention.
• Cognitive impairment.