Comparison of Heated vs. Pulsed Radiofrequency Treatment of the Genicular Nerves for Osteoarthritis Knee Pain
Comparison of Heated vs. Pulsed Radiofrequency Treatment of the Genicular Nerves for Osteoarthritis Knee Pain
This is a prospective, randomised, interventional, double blinded study to compare the
 clinical outcomes of thermal vs. pulsed radiofrequency (RF) treatment of the genicular nerves
 in patients with painful osteoarthritis (OA) of the knee.

 Population: 60 patients, aged 50 and above, with painful OA of the knee. Interventional
 measures: Pulsed or heated RF treatment of the genicular nerves of the involved knee.

 Outcome measures: primary - fraction of patients experiencing improvement of 50% or higher in
 their average pain rating during stair climbing.

 secondary - improved quality of life

 -  improved functional capacity

 -  comparison of side effects and adverse events

 -  change in the consumption of analgesic medications
Pre-intervention assessment Pain intensity during stairs climbing using VAS 1-100 numerical
 rating scale. Analgesics consumption. Quality of life using WOMAC questionaires. A physician
 will further examine them and will enroll them signing an informed concent.

 A diagnostic block with lidocaine 2% (2ml for each nerve - total volume of 6ml per knee) of 3
 genicular nerves (upper medial and lateral and lower medial branches) will be performed,
 guided either by ultrasound or by fluoroscopy.

 Participants will be asked to fill in a VAS questionnaire shortly (up to one hour) after
 undergoing the diagnostic blocks.

 Participants achieving a relief of >50% in pain intensity during stairs climbing will be
 considered to have responded to the diagnostic block and will be randomized.

 Randomization

 Recruited participants will be randomized into two groups:

 1. Heated RF ablation

 2. Pulsed RF ablation

 Blinding Both the patient and the assessing physician will be blinded to the group to which
 the patient has been allocated. The physicians performing the treatment will be blinded as
 well.

 Intervention

 Heated RF ablation of the genicular nerves will be performed as follows:

 1. In the supine position, aseptic preparation of the skin and sterile coverage of the
 procedure area will take place.

 2. After the administration of local anesthesia to the skin with lidocain 2% (1-1.5cc for
 each injection site, fluoroscopy guided placement of three 22 gauge 50mm or 100mm
 straight RF cannulas in the proximity of 3 of the genicular nerves: 2 on both sides of
 the distal femoral shaft-epiphysis border and one on the medial proximal tibial
 epiphyseal-shaft border.

 3. Sensory stimulation at 50 Hertz will be used to test the proper position of the needle,
 expected to generate paresthesia in the distribution of the affected nerve, at a voltage
 in the range of 0.3-0.8 Volts. Motor stimulation at 2 Hz will be used to exclude
 proximity of the cannula to motor nerves.

 4. 1 ml of 2% lidocaine will be injected into each cannula.

 5. 180 sec 80 degrees heated RF ablation of the nerves will be performed. Needles will be
 left in place for additional 420 seconds to match the treatment duration of the pulsed
 RF group.

 6. Injection of a total amount of 80 mg methylprednisolone and lidocaine 2% 2cc to the 3
 intervention sites.

 Pulsed RF ablation of the genicular nerves will be performed similarly to the heated RF
 ablation with the only difference being that the treatment will include a 600 sec of 42
 degrees heating of the three-genicular nerves.

 Blinding Both the patient the assessing and performing physicians will be blinded to the
 group to which the patient has been allocated.

 Post-procedural assessment Participants will be assessed 3 days and 30 days after the
 procedure (phone questionnaires) and a clinical follow-up visits in 3 and 6 months after the
 procedure.

 The assessment will include:

 1. Two telephone interviews, in which the patient will report the average severity of pain
 on a 1 to 100 numerical rating scale and will fill up a WOMAC questionnaire regarding
 the treated knee in the prior 24 hours.

 2. Two clinic follow-up visit, during which the patients will fill-in a questionnaire of
 pain intensity after stairs climbing using VAS 1-100 numerical rating, analgesic
 consumption, quality of life measures using the WOMAC questionaire. Questionnaires
 filling-in will be aided and supervised by research assistants blinded to the
 intervention the participants have received.
Inclusion Criteria:

 -  Radiologically proven OA of knee with a 2. Kellgren-Lawrence scale (K-L score) of 3 to
 4.

 -  Clinically proven OA of knee with an Oxford knee score of 0 to 30 (representing
 moderate to severe OA).

 -  Chronic knee pain due to the OA of knee (>3 months) of at least moderate severity by a
 Visual Analogue Scale (VAS) 4 and above.

 -  Signed informed consent

 Exclusion Criteria:

 -  Acute knee pain

 -  Disease that preclude per clinician decision interventional treatment.

 -  Allergic reaction to the injected substances (triamcinolone, lidocaine)

 -  Injections to the knee during the 3 months preceding recruitment

 -  Distorted knee intervention due to any cause, which interferes with the radiological
 identification of targeted RF sites.

 -  Anticoagulation treatment that cannot be stopped.