Genicular Radiofrequency Ablation Following Total Knee Arthroplasty (GRATKA)

February 2, 2026 updated by: University of Calgary

The Safety and Efficacy of Genicular Radiofrequency Ablation for Patients With Persistent Knee Pain Following Total Knee Arthroplasty - A Triple Blinded Randomized Sham-Controlled Trial

Currently, nearly 1 million total knee arthroplasties (TKA) are performed yearly in the United States. Three million are projected to be performed in 2040. Between 15-30% of all patients who undergo TKA have continued pain, reduced quality of life and functional impairments that cannot be attributed to hardware failure/loosening or infection. Treatment options for persistent post TKA pain (failed TKA) are limited. There is a need for minimally invasive, and effective pain and disability modulating interventions for patients with failed TKA. Genicular radiofrequency ablation (GRFA) has been described, refined, and validated as an effective minimally invasive intervention to control refractory knee pain secondary to knee osteoarthritis (OA) as evidenced by three favorable meta-analyses published in 2021 alone.3-5 GRFA is a minimally invasive percutaneous procedure that utilizes thermal energy to coagulate nerves from the knee. Though sometimes used in practice, there is limited research describing and evaluating GRFA for patients with failed TKA. This will be the first trial to evaluate the safety and efficacy of GRFA in patients with failed TKA using a robust study design and up-to-date, evidence-based selection criteria and technique.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not 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

The general objective of this study is to determine the safety and efficacy of GRFA in patients with failed TKA. The central hypothesis is that GRFA is safe and more efficacious in improving pain and function than sham GRFA. A triple blinded randomized sham-controlled trial design will be used. Patients with failed TKA will be recruited and randomized into either a thermal or sham GRFA group. Patient selection criteria and GRFA procedural technique will incorporate refinements based on expanded understanding from recent research. Outcomes will be assessed prior to and at 3, 6 and 12 months post-GRFA. The primary outcome measures will be between group difference in the change in pain (NRS) between pre- and 6 months post. Secondary outcomes will include safety and changes in function (WOMAC; sit-stand test; strength; range of motion & balance), participants' impression of change, perceived need for revision arthroplasty, analgesic use, and quality-of-life. Crossover will be offered to participants in the sham group at 6 months post-treatment. Data will be analyzed using descriptive, linear mixed-effects model and Kaplan-Meier Survival Curve statistics. The proposed research is innovative and important as it uses a robust study design to evaluate the safety and efficacy of an emerging RFA intervention in a prevalent suffering patient population.

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.
44

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

  • Canada
    • Alberta
      • Calgary, Alberta, Canada, T2E2P5
        • Vivo Cura Health

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

50 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • >1 year post TKA
  • persistent knee pain > 4/10 in intensity on average over the prior week of one of the post-TKA knees
  • refractory to conventional treatment (i.e., physiotherapy, medication, etc.)
  • ≥80% pain relief with a single fluoroscopically guided local anesthetic block using 0.5 mL of 2% lidocaine for the medial and lateral branches of the nerve to the vastus intermedialis, nerve to the vastus lateralis*, inferior medial genicular nerve, infrapatellar branch of the saphenous nerve, and the recurrent fibular nerve. 0.5 mL will be injected over 2 spots (1.5 cm apart) for each of the superior medial and lateral genicular nerves corresponding to the sites of the RF cannulae for the bipolar strip lesions. *Blocks will be combined fluoroscopy/ultrasound guided.

Exclusion Criteria:

  • Infection (peri-prosthetic, joint, systemic, skin/soft tissue overlying the knee to be treated)
  • Prosthetic loosening or failure, periprosthetic fracture
  • Severe psychiatric disorder
  • Non-genicular lower extremity pain source from the spine (i.e., radiculopathy or neurogenic claudication) or peripheral joints (i.e., hip osteoarthritis)
  • Peripheral vascular disease causing vascular claudication
  • Connective tissue/inflammatory joint disease/widespread soft tissue pain disorder
  • Poor tolerance of injection procedures (as observed from the prognostic local anesthetic blocks)
  • Allergy to local anesthetic, synovial expansion into the anticipated path(s) of the local anesthetic needle/RF cannula as determined by ultrasound scanning
  • Uncontrolled bleeding diathesis
  • Pregnancy
  • Pacemaker or neurostimulator
  • Inability to complete Patient-Reported Outcome Measures due to cognitive or language limitations.

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: Crossover Assignment
  • Masking: Triple

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: Group 1 (GRFA)
After the cannulae are placed and tines deployed, a single lesion (30 second ramp-up time; 80C x 2 minutes) will be made at each of the medial and lateral branches of the nerve to the vastus intermedialis, nerves to the vastus lateralis and medialis, recurrent fibular nerve, inferior medial genicular nerve. One bipolar strip lesion (intercannula distance 1.5 cm; anticipated strip lesion length 2.0 cm) at the superior medial and lateral genicular nerves will be made to accommodate anatomical variability.
Procedure: Genicular Radiofrequency Ablation
After the cannulae are placed and tines deployed, a single lesion (30 second ramp-up time; 80C x 2 minutes) will be made at each of the medial and lateral branches of the nerve to the vastus intermedialis, nerves to the vastus lateralis and medialis, recurrent fibular nerve, inferior medial genicular nerve. One bipolar strip lesion (intercannula distance 1.5 cm; anticipated strip lesion length 2.0 cm) at the superior medial and lateral genicular nerves will be made to accommodate anatomical variability.
Active Comparator: Group 2 (Sham)
The same procedure will be employed as per Group 1 - However, the sham procedure will involve no electrical signal applied to the participant.
Procedure: Sham Genicular Radiofrequency Ablation
After the cannulae are placed and tines deployed, a single lesion (no electrical signal applied to patient) will be made at each of the medial and lateral branches of the nerve to the vastus intermedialis, nerves to the vastus lateralis and medialis, recurrent fibular nerve, inferior medial genicular nerve. One bipolar strip lesion (intercannula distance 1.5 cm; anticipated strip lesion length 2.0 cm) at the superior medial and lateral genicular nerves will be made to accommodate anatomical variability.

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
Average Pain Intensity Over the Prior week (0 - 10)
Time Frame: 6 months
Numerical pain rating scale (0 - 10) with higher scores indicating a worse outcome
6 months
Change in pain intensity between pre- and 6-months post-intervention
Time Frame: 6 months
Numerical Pain rating scale (NPRS) 6 month minus NPRS pre-intervention, with increased negative scores indicating a better outcome
6 months

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
Proportion of participants exceeding 50% pain relief
Time Frame: 6 months
Proportion of participants that experience ≥ 50% pain relief
6 months
Proportion of participants exceeding Minimal Clinically Important Difference (MCID) pain relief
Time Frame: 6 months
Proportion of participants that experience MCID knee pain relief
6 months
Safety - Adverse Events
Time Frame: 1-week, 3, 6 and 12-months post-intervention
Presence of self-reported complications
1-week, 3, 6 and 12-months post-intervention
Average Pain Intensity Over the Prior Week (0 - 10)
Time Frame: 3 and 12-months post-intervention
Numerical pain rating scale (0 - 10) with higher scores indicating worse outcomes
3 and 12-months post-intervention
Western Ontario and McMaster Universities Arthritis Index (WOMAC)
Time Frame: 3, 6 and 12-months post-intervention
Measure of pain (0 - 20), stiffness (0 - 8) and physical function (0 - 68) with higher scores indicating wore pain, stiffness and functional limitations
3, 6 and 12-months post-intervention
The Clinical Global Impressions Scale (CGI)
Time Frame: 3, 6 and 12-months post-intervention
Patient reported global impression of change (1 = Very Much Improved to 7 = Very Much Worse)
3, 6 and 12-months post-intervention
Perceived Need for Revision Arthroplasty
Time Frame: Baseline (Prior to), 3, 6 and 12-months post-intervention
"If revision surgery of your knee replacement was available to you, how interested would you be in having it at this time?" Y or N
Baseline (Prior to), 3, 6 and 12-months post-intervention
Analgesic Use
Time Frame: Baseline (Prior to), 3, 6 and 12-months post-intervention
Quantitative Analgesic Questionnaire
Baseline (Prior to), 3, 6 and 12-months post-intervention
Health-related Quality of Life
Time Frame: Baseline (Prior to), 3, 6 and 12-months post-intervention
EQ-5D-5L
Baseline (Prior to), 3, 6 and 12-months post-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.
University of Calgary

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: Ashley Smith, PhD, University Of Calgary

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Actual)

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.
May 11, 2022

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.
December 1, 2026

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.
December 1, 2026

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).
February 18, 2022

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.
March 8, 2022

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.
March 17, 2022

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.
February 5, 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.
February 2, 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.
January 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.
  • REB21-2105

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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