Genicular Nerve Radiofrequency Ablation Versus Hyaluronic Acid Injection for Knee Osteoarthritis Pain (RF-PROSPECTIU)

November 11, 2026 updated by: Laura Pallarès Valls, Hospital Universitari Joan XXIII de Tarragona.

A Prospective Comparative Study of Conventional Conservative Treatment Versus Genicular Radiofrequency Ablation in Non-Surgical Knee Osteoarthritis: A Randomized Controlled Trial of Thermal Radiofrequency of the Genicular Nerves Versus Intra-Articular Hyaluronic Acid

The goal of this clinical trial is to learn if thermal radiofrequency ablation of the genicular nerves (the nerves that carry pain signals from the knee) works better than a single injection of hyaluronic acid into the knee to relieve pain in adults with knee osteoarthritis who have not improved with conservative treatment. The study also includes patients with severe knee osteoarthritis who are not candidates for knee replacement surgery.

The main questions it aims to answer are:

  • Does genicular nerve radiofrequency reduce knee pain during movement more than hyaluronic acid over 12 months?
  • Does it improve knee function and quality of life, and does its effect last longer?

Researchers will compare radiofrequency ablation with hyaluronic acid injection to see which treatment gives greater and longer-lasting pain relief.

Participants will:

  • Be randomly assigned to one of the two treatments.
  • If assigned to radiofrequency, first receive a diagnostic nerve block with local anesthetic. Only those whose pain decreases by at least 50% will then receive radiofrequency ablation, in a single ultrasound-guided session.
  • If assigned to hyaluronic acid, receive a single injection of hyaluronic acid into the knee.
  • Attend follow-up visits at 1, 3, 6 and 12 months, where they will rate their pain and answer questionnaires about knee function, overall status and quality of life.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Knee osteoarthritis is a leading cause of chronic pain and disability. Conventional conservative treatments, such as non-steroidal anti-inflammatory drugs and intra-articular hyaluronic acid, provide partial and time-limited relief. Thermal radiofrequency ablation of the genicular nerves is a minimally invasive technique that interrupts pain transmission from the knee joint. Most published studies have short follow-up (3-6 months), and evidence is scarce in patients with advanced osteoarthritis (Kellgren-Lawrence grade IV) who are not candidates for total knee arthroplasty because of severe comorbidity, morbid obesity or a documented multidisciplinary decision.

Design: single-center, randomized, parallel-group (1:1) controlled trial conducted at Hospital Universitari Joan XXIII de Tarragona (Spain). Patients and clinicians are not blinded; the outcome assessor and the statistician are blinded to treatment allocation.

Randomization: computer-generated sequence (sealedenvelope.com) with variable block sizes, stratified by Kellgren-Lawrence grade (II-III vs IV) and body mass index (<40 vs >=40 kg/m2).

Interventions: in the radiofrequency group, an ultrasound-guided diagnostic block of the superomedial, superolateral and inferomedial genicular nerves (1 ml of 1% lidocaine per nerve) is performed first. Patients with at least 50% pain reduction within 4 hours undergo ultrasound-guided thermal radiofrequency ablation of the same nerves (80 C for 90 seconds per nerve). Patients with a negative block do not receive radiofrequency, are withdrawn from the study and are reported in the CONSORT flow diagram. In the hyaluronic acid group, patients receive a single 6 ml intra-articular injection of high molecular weight hyaluronic acid (hylan G-F 20 or similar).

Sample size: 25 patients per group are required to detect a minimal clinically important difference of 2 points in the visual analogue scale (standard deviation 2.5, power 80%, two-sided alpha 0.05). Allowing for 20% losses over 12 months, 35 patients per group (70 in total) will be included.

A pre-specified subgroup analysis will compare treatment response in Kellgren-Lawrence grade II-III versus grade IV patients, and according to comorbidity (Charlson Comorbidity Index) and body mass index. Health-related quality of life data will be collected for a potential cost-effectiveness analysis.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
70

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Spain
    • Tarragona
      • Tarragona, Tarragona, Spain, 43005
        • Hospital Universitari Joan XXIII de Tarragona
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Adults (18 years or older) with symptomatic knee osteoarthritis of more than 6 months' duration.
  • Pain during movement >4 on a 0-10 visual analogue scale.
  • Failure of conservative treatment: pain during movement >4 despite at least 3 months of NSAIDs and/or rehabilitation (physical therapy), documented in the medical record. Patients with a documented contraindication to NSAIDs may be included if they have undergone rehabilitation.
  • Radiographic Kellgren-Lawrence grade II or III, or
  • Kellgren-Lawrence grade IV in patients who are not candidates for total knee arthroplasty because of at least one of the following: body mass index >39.9 kg/m2; Charlson Comorbidity Index >=5 (original, not age-adjusted); or a documented multidisciplinary decision of the Orthopaedic Surgery Department.
  • Signed informed consent.

Exclusion Criteria:

  • Acute or chronic knee joint infection.
  • Intra-articular hyaluronic acid or corticosteroid injection in the previous 6 months.
  • Coagulopathy or anticoagulant treatment that does not allow a safe therapeutic window for the procedure.
  • Major lower limb surgery in the previous 6 months that may affect function or pain of the index knee (including contralateral total or partial knee arthroplasty, hip arthroplasty, or tibial or femoral osteotomy).
  • Cardiac pacemaker or metallic implant (contraindication for radiofrequency).
  • Known allergy to hyaluronic acid.
  • Severe dementia.
  • Institutionalized patients.
  • Decompensated systemic disease.
  • Active neurological or inflammatory rheumatological disease.
  • Terminal oncological disease.
  • Inability to understand the study questionnaires.
  • Radiofrequency arm only: negative diagnostic genicular nerve block (<50% pain reduction within 4 hours).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Genicular Nerve Radiofrequency Ablation

Ultrasound-guided diagnostic block of the superomedial, superolateral and inferomedial genicular nerves with 1 ml of 1% lidocaine per nerve. Participants with at least 50% pain reduction within 4 hours undergo ultrasound-guided thermal radiofrequency ablation of the same three nerves (80 C for 90 seconds per nerve) in a single session. Participants with a negative block do not receive radiofrequency and are withdrawn from the study.
Procedure: Thermal Radiofrequency Ablation of the Genicular Nerves

Ultrasound-guided thermal radiofrequency ablation (80 C, 90 seconds per nerve) of the superomedial, superolateral and inferomedial genicular nerves, performed only after a positive diagnostic block (>=50% pain reduction within 4 hours after 1 ml of 1% lidocaine per nerve).
Active Comparator: Intra-articular Hyaluronic Acid

Single intra-articular injection of 6 ml of high molecular weight hyaluronic acid (hylan G-F 20, Synvisc-One, or similar) into the index knee.
Device: Intra-articular Hyaluronic Acid

Single 6 ml intra-articular injection of high molecular weight hyaluronic acid into the index knee.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Knee Pain During Movement (Visual Analogue Scale)
Time Frame: Baseline, 1, 3, 6 and 12 months after the intervention

Pain during movement (walking or climbing stairs) in the index knee, measured on a 100 mm visual analogue scale and recorded in cm with one decimal (0 = no pain, 10 = worst imaginable pain). Higher scores indicate worse pain.
Baseline, 1, 3, 6 and 12 months after the intervention

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Knee Pain at Rest (Visual Analogue Scale)
Time Frame: Baseline, 1, 3, 6 and 12 months after the intervention

Pain at rest in the index knee, measured on a 100 mm visual analogue scale and recorded in cm with one decimal (0 = no pain, 10 = worst imaginable pain). Higher scores indicate worse pain.
Baseline, 1, 3, 6 and 12 months after the intervention
Change in Knee Function (WOMAC)
Time Frame: Baseline, 1, 3, 6 and 12 months after the intervention

Western Ontario and McMaster Universities Osteoarthritis Index (Likert 3.1). Total score 0-96 and subscales for pain (0-20), stiffness (0-8) and physical function (0-68). Higher scores indicate worse symptoms and function.
Baseline, 1, 3, 6 and 12 months after the intervention
Proportion of Participants Achieving the Minimal Clinically Important Difference in Pain
Time Frame: 1, 3, 6 and 12 months after the intervention

Percentage of participants with a reduction of at least 2 points from baseline in pain during movement (visual analogue scale, 0-10).
1, 3, 6 and 12 months after the intervention
Analgesic Consumption
Time Frame: Baseline, 1, 3, 6 and 12 months after the intervention

Number of days with analgesic use in the previous 4 weeks (0-28) and most potent analgesic used (none, paracetamol, NSAID, weak opioid, strong opioid).
Baseline, 1, 3, 6 and 12 months after the intervention
Number of Participants With Adverse Events
Time Frame: Up to 12 months after the intervention

Adverse events related to the diagnostic block, radiofrequency ablation or hyaluronic acid injection, systematically recorded at each visit.
Up to 12 months after the intervention
Retreatment or Rescue Treatment
Time Frame: Up to 12 months after the intervention

Proportion of participants requiring retreatment, rescue treatment (including corticosteroid injection) or indication of total knee arthroplasty, and time to first retreatment or rescue treatment.
Up to 12 months after the intervention
Health-Related Quality of Life (EQ-5D-5L)
Time Frame: Baseline, 6 and 12 months after the intervention

EQ-5D-5L descriptive system (5 dimensions, 5 levels; utility index calculated with the Spanish value set, where 1 = full health and higher values indicate better health) and EQ-VAS (0-100, higher scores indicate better health).
Baseline, 6 and 12 months after the intervention
Rate of Negative Diagnostic Genicular Nerve Blocks
Time Frame: 4 hours after the diagnostic block

Percentage of participants allocated to the radiofrequency arm with less than 50% pain reduction within 4 hours after the diagnostic block, who therefore do not receive radiofrequency ablation.
4 hours after the diagnostic block
Patient Global Assessment
Time Frame: Baseline, 1, 3, 6 and 12 months after the intervention

Patient global assessment of the impact of knee osteoarthritis, measured on a 100 mm visual analogue scale (0 = very well, 100 = very poor). Higher scores indicate worse status.
Baseline, 1, 3, 6 and 12 months after the intervention
Patient Global Impression of Change (PGIC)
Time Frame: 1, 3, 6 and 12 months after the intervention

Single 7-point item from "very much better" to "very much worse" compared with before the study treatment. Responders are participants reporting "much better" or "very much better".
1, 3, 6 and 12 months after the intervention
Proportion of OMERACT-OARSI Responders
Time Frame: 1, 3, 6 and 12 months after the intervention

Responder according to OMERACT-OARSI criteria, based on pain during movement, WOMAC physical function and patient global assessment, each expressed on a 0-100 scale: improvement in pain or function >=50% and >=20 points, or improvement >=20% and >=10 points in at least two of the three domains.
1, 3, 6 and 12 months after the intervention

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hospital Universitari Joan XXIII de Tarragona.

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Institut Investigacio Sanitaria Pere Virgili

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Laura Pallarès Valls, MD, Hospital Universitari Joan XXIII de Tarragona.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 21, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 21, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 28, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 13, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 11, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Ceim-116/2026
  • 116/2026 (Other Identifier: CEIm IISPV (Research Ethics Committee) reference number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared publicly, as participant consent for data sharing was not obtained and data are protected under the EU General Data Protection Regulation (GDPR). Data will be pseudonymized using participant codes and entered into REDCap, where the statistical analysis will be performed. Aggregated results will be published in peer-reviewed journals.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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