Efficacy of Cooled and Monopolar Radiofrequency Ablation of the Geniculate Nerves for the Treatment of Chronic Osteoarthritic Knee Pain

Study Overview
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Brief Summary
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This is a single center randomized controlled trial. Approximately 102 patients will be randomized to one of two treatment groups: cooled radiofrequency or conventional monopolar radiofrequency ablation. Patients with chronic knee pain, with moderate to severe osteoarthritis according to the Kellgren-Lawrence scale for at least 6 months who have failed conservative therapy will be screened for the study. Then, patients will be enrolled based on reporting ≥50% pain relief after a fluoroscopic guided single diagnostic block of the geniculate nerves (superior medial, superior lateral, and inferior medial) with 0.5 ml of local anesthetic (2% Lidocaine). Baseline data will be collected for all enrolled patients. Outcomes will be measured at 1, 4, 12, 24 and 52 weeks. Outcome measures will be: Visual analogue scale (VAS) both while at rest and during ambulation, Oxford knee scores, WOMAC, and global perceived effect.

Official Title
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A Prospective Double Blind, Randomized Control Trial to Compare the Efficacy of Cool Radiofrequency Ablation vs. Conventional Monopolar Radiofrequency Ablation of the Geniculate Nerves for the Treatment of Chronic Osteoarthritic Knee Pain

Conditions
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Osteoarthritis, Knee

Intervention / Treatment
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* Procedure: Genicular nerve radiofrequency ablation
* Device: Pain Management Radiofrequency Kit


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who have given their written informed consent to participate in this clinical study based on voluntary agreement after a thorough explanation of the patient's participation is provided to them. Female patients who are not pregnant and do not plan to become pregnant during the study. Females of child bearing potential must provide a negative pregnancy test provided by the study physician and must be using reliable contraception and must continue to use reliable contraception until study completion at 52 weeks. Non-childbearing potential is defined as postmenopausal for at least 2 years or surgical sterilization or hysterectomy at least 3 months before study start. Must be older than 18 years old.. Must have chronic knee pain for at least 6 months. Must have radiologic evidence of OA of the knee, grade 2-4 based on the Kellgreen-Lawrence scale. Persistent pain despite the use of conservative treatment (physical therapy, oral analgesic, steroid injections). Must have a VAS score of at least 5 with ambulation. Subjects must be on a stable dose of pain medication regimen for at least 2 months. Greater than or equal to 50% improvement from blocks in target knee for duration of the anesthetic. Exclusion Criteria: Knee pain must not be acute. Previous total knee replacement. Evidence of connective tissue disease. Patients who have a BMI greater than 40. Evidence of serious neurological or psychiatric disorders. Current opioid use must not be greater than or equal to 90 mg morphine equivalent per 24 hour period. Must not have radicular pain in the affected limb. Patients with uncorrected coagulation disorders or who are on anticoagulation therapy and cannot interrupt the therapy. Patients who have pacemakers or generators. Patient who are pregnant, breast-feeding or women of childbearing potential with positive pregnancy tests. Sexually active female patients of childbearing potential who are not willing to use adequate contraceptive measures to avoid pregnancy until week 52 of the study. Sexually active male patients who are not willing to use adequate contraceptive measures until week 52 of the study. Adequate methods of birth control include the following: Hormonal contraception (female patients) or use of at least one acceptable double-barrier method (for example: diaphragm plus spermicidal agent or condoms (male or female) plus spermicidal agent.), vasectomy, intrauterine device, and/or exclusive sexual partner for whom one of the above acceptable methods applies. Patients who have cancer or a past history of any cancer within 5 years prior to the time of informed consent, with the exception of basal cell or squamous cell carcinoma of the skin. Human immunodeficiency virus (HIV) infection or a clinically significant infection. A clinically significant disorder such as cerebrovascular disease, pulmonary infarction, ischemic heart disease, cardiac dysrhythmia, myocardial infarction, or congestive heart failure. Uncontrolled diabetes, uncontrolled pulmonary disease, or uncontrolled hypertension. Patients who have evidence of major psychiatric disease, mental disorder, drug dependency, alcohol dependency, or substance abuse disorders. Any patient with a medical condition and/or disease that the Investigator believes could affect the study results or the safe conduct of the study. Patients who are receiving compensation according to Workers' Compensation Act or are involved in personal injury litigation. Patients who participated in another clinical study within 3 months prior to the time of informed consent, or who are expected to participate in another study during the period of this study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Cooled radiofrequency ablation<br>Patient is placed in supine position on a fluoroscopic table with a pillow under the popliteal fossa. An anterio-posterior fluoroscopic view of the tibio-femoral joint is obtained. Skin and subcutaneous tissues are anesthetized and a 17 g introducer needle is advanced percutaneously towards the junction of shaft with epicondyle until bone contact is made. The needle is then laterally displaced away from the bone. This process is performed at the superior medial and superior lateral aspects of the femur, and the inferior medial aspect of the tibia. The fluoroscope is placed in lateral view to guide the needle depth to be at the medial third of the femur or tibia. A cooled radiofrequency probe from a Pain Management Radiofrequency kit is advanced through the introducer. Following sensory and motor stimulation, cooled genicular nerve radiofrequency ablation is carried out at 60 Celsius for 150 seconds. | Procedure: Genicular nerve radiofrequency ablation<br>* Radiofrequency ablation uses the electrical field generated by a radiofrequency probe inserted near a nerve responsible for pain. Chronic pain sensation in the knee is generated at the genicular nerves. The physician locates the affected genicular nerve by injecting an anesthetic (lidocaine) that produces a sensory nerve block (i.e. anesthetic pain relief). A radiofrequency probe is inserted percutaneously near the affected nerve using a cannula/introducer and is then connected to a radiofrequency generator. This is set to stimulate sensory and motor response, which allows the physician to adjust the probe position for effective and safe treatment. Then radiofrequency is applied to the tissue for a short time (up to 150 seconds) in order to generate a target temperature (no more than 80 degrees Celsius). The increase in the temperature of the tissue ablates the affected nerve producing pain relief.<br>* Other names: genicular neurotomy using radiofrequency;Device: Pain Management Radiofrequency Kit<br>* The pain management radiofrequency consists of a radiofrequency generator, a radiofrequency probe and an introducer/cannula. The introducer cannula is used to percutaneously position the probe in the appropriate location for treatment. The radiofrequency probe is an electrode that delivers the electric field that heats up the tissue. In cooled radiofrequency the electrode is surrounded by a water jacket that cools it while heat is generated. The generator is the instrument that provides the radiofrequency according to a particular temperature and time program. Temperature, tissue impedance and radiofrequency power are lalso monitored by the generator.<br>|
| Active Comparator: Monopolar radiofrequency ablation<br>Patient is placed in supine position on a fluoroscopic table with a pillow under the popliteal fossa. An anterio-posterior fluoroscopic view of the tibio-femoral joint is obtained. Skin and subcutaneous tissues are anesthetized and a 16 g introducer needle is advanced percutaneously towards the junction of shaft with epicondyle until bone contact is made. The needle is then laterally displaced away from the bone. This process is performed at the superior medial and superior lateral aspects of the femur, and the inferior medial aspect of the tibia. The fluoroscope is placed in lateral view to guide the needle depth to be at the medial third of the femur or tibia. A conventional radiofrequency probe from a Pain Management Radiofrequency kit is advanced through the introducer. Following sensory and motor stimulation, genicular nerve radiofrequency ablation will be carried out at 80 Celsius for 90 seconds. | Procedure: Genicular nerve radiofrequency ablation<br>* Radiofrequency ablation uses the electrical field generated by a radiofrequency probe inserted near a nerve responsible for pain. Chronic pain sensation in the knee is generated at the genicular nerves. The physician locates the affected genicular nerve by injecting an anesthetic (lidocaine) that produces a sensory nerve block (i.e. anesthetic pain relief). A radiofrequency probe is inserted percutaneously near the affected nerve using a cannula/introducer and is then connected to a radiofrequency generator. This is set to stimulate sensory and motor response, which allows the physician to adjust the probe position for effective and safe treatment. Then radiofrequency is applied to the tissue for a short time (up to 150 seconds) in order to generate a target temperature (no more than 80 degrees Celsius). The increase in the temperature of the tissue ablates the affected nerve producing pain relief.<br>* Other names: genicular neurotomy using radiofrequency;Device: Pain Management Radiofrequency Kit<br>* The pain management radiofrequency consists of a radiofrequency generator, a radiofrequency probe and an introducer/cannula. The introducer cannula is used to percutaneously position the probe in the appropriate location for treatment. The radiofrequency probe is an electrode that delivers the electric field that heats up the tissue. In cooled radiofrequency the electrode is surrounded by a water jacket that cools it while heat is generated. The generator is the instrument that provides the radiofrequency according to a particular temperature and time program. Temperature, tissue impedance and radiofrequency power are lalso monitored by the generator.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evidence of Change in Knee Pain | A 100mm visual analog scale (VAS) score at 24 weeks post-treatment will be compared to baseline score to measure change in pain level. Change in Pain = (VAS at 24 weeks) - (VAS at baseline) The VAS consists of a 100 mm long line without marks between the 0 and 100 mm edges. Range of scale is 0 to 100 mm, where 0 means no pain and 100 mm means the worst pain imaginable. A negative change in VAS means a reduction in pain level after 24-weeks of treatment. | 24 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evidence of Functional Changes | Standard score system (Oxford Knee Score) was used to assess functional changes at 24 weeks of treatment relative to baseline. The Oxford Knee Score (OKS) measures the level of function, activities of daily living and how they have been affected by knee pain. The OKS is a obtained from a 12-item patient reported questionnaire. Each item has 5 categories, scored from 0 to 4, with 0 being the worst outcome and 4 the best outcome of each item. The OKS is the sum of all item scores. Therefore, it ranges from 0 to 48, with 0 being the worst functional outcome possible and 48 is the best functional outcome possible. Change in OKS = (OKS at 24 weeks) - (OKS at baseline) A positive Change in OKS indicates an improvement in extent of function. | 24 weeks |