Cooled Radiofrequency vs. Hyaluronic Acid to Manage Knee Pain


About this study

This is a prospective, randomized, multicenter comparison study examining the outcomes of subjects with osteoarthritis and knee pain undergoing a procedure to create a radiofrequency lesion of the genicular nerves with the Cooled Radiofrequency Ablation (CRFA) system compared to subjects receiving Hyaluronic Acid (HA). Approximately 168 subjects will be enrolled into this study, with subjects undergoing either CRFA or HA injection in a 1:1 randomization scheme. Follow-up will be conducted for 12 months post-CRFA, with the primary endpoint being completed at month 6. Subjects randomized to the comparison (HA) group will have the option to cross-over to the neurotomy group after completing the 6-month endpoint assessment. They will be followed for an additional 6 months. Pain, overall outcome, quality of life, pain medication use, and adverse events will be compared between the two treatment groups to determine success.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  1. Age ≥ 21 years
  2. Able to understand the informed consent form and provide written informed consent and able to complete outcome measures
  3. Chronic knee pain for longer than 6 months that interferes with functional activities (for example, ambulation, prolonged standing, etc.)
  4. Continued pain in the target knee despite at least 3 months of conservative treatments, including activity modification, home exercise, protective weight bearing, and/or analgesics (for example, acetaminophen or non-steroidal anti-inflammatory drugs [NSAIDs])
  5. Positive response (defined as a decrease in numeric pain scores of at least 50%) to a single genicular nerve block of the index knee
  6. Pain on NRS ≥ 6 on a 10-point scale for the index knee
  7. Radiologic confirmation of arthritis (x-ray/MRI/CT) of OA grade of 2 (mild), 3 (moderate) or 4 (severe) noted within 6 months for the index knee
  8. An intra-articular hyaluronic acid injection is indicated as an appropriate treatment option
  9. WOMAC Knee Score group at baseline of Score of ≥ 2 (0 to 4 scale) on WOMAC question 1 (Pain) and a mean score of ≥ 1.5 on all five questions of the WOMAC pain subscale.
  10. Analgesics including membrane stabilizers such as Neurontin/gabapentin and antidepressants for pain such as Cymbalta duloxetine must be clinically stable (defined as stable dosage for ≥ 6 weeks prior to the screening visit) and shall not change during the course of the study without approval of the investigator
  11. Agree to see one physician (study investigator) for knee pain during the study period
  12. Willing to utilize double barrier contraceptive method if of child bearing potential
  13. Willing to delay any surgical intervention for the index knee for the period of the study follow up
  14. Willingness to provide informed consent and to comply with the requirements of this protocol for the full duration of the study

Exclusion Criteria:

  1. Evidence of inflammatory arthritis (for example, rheumatoid arthritis) or other systemic inflammatory condition (for example, gout) that could cause knee pain
  2. Evidence of neuropathic pain affecting the index knee
  3. Previous or pending lower limb amputation
  4. Intra-articular steroid, platelet rich plasma (PRP), stem cell, or arthroscopic debridement/lavage injection into the index knee within 180 days from informed consent
  5. Previous hyaluronic acid injection in the index knee
  6. Prior radiofrequency ablation of the genicular nerves of the index knee
  7. Prior partial, resurfacing, or total knee arthroplasty of the index knee (residual hardware)
  8. Clinically significant ligamentous laxity of the index knee
  9. Clinically significant valgus/varus deformities or evidence of pathology (other than osteoarthritis of knee) that materially affects gait or function of the knee or is the underlying cause of the knee pain and/or functional limitations
  10. Body mass index (BMI) > 40 kg/m2
  11. Extremely thin patients and those with minimal subcutaneous tissue thickness that would not accommodate a radiofrequency lesion of up to 14 mm in diameter to limit the risk of skin burns
  12. Pending or active compensation claim, litigation, or disability remuneration (secondary gain)
  13. Pregnant, nursing or intent of becoming pregnant during the study period
  14. Chronic pain associated with significant psychosocial dysfunction
  15. Beck's Depression Index score of > 22 (indicates clinically depressed state)
  16. Allergies to any of the medications to be used during the procedures, including known hypersensitivity (allergy) to hyaluronate preparations or allergies to avian or avian-derived products (including eggs, feathers, or poultry)
  17. Active joint infection or systemic or localized infection at needle entry sites (subject may be considered for inclusion once infection is resolved)
  18. History of uncontrolled coagulopathy, ongoing coagulation treatment that cannot be safely interrupted for procedure, or unexplained or uncontrollable bleeding that is uncorrectable
  19. Identifiable anatomical variability that would materially alter the procedure as described in the protocol
  20. Within the preceding 2 years, subject has suffered from active narcotic addiction, substance, or alcohol abuse
  21. Current prescribed opioid medications greater than 60 morphine equivalent daily opioid dose
  22. Uncontrolled immunosuppression (e.g. AIDS, cancer, diabetes, etc.)
  23. Subject currently implanted with pacemaker, stimulator or defibrillator.
  24. Participating in another clinical trial/investigation within 30 days prior to signing informed consent
  25. Subject unwilling or unable to comply with follow up schedule or protocol requirements

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Matthew Pingree, M.D.

Closed for enrollment

Contact information:

Midhat Mujic R.R.T., L.R.T.


More information


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