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

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

Interventional

Enrollment (Estimated)

44

Phase

  • 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 Locations

    • 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

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
Intervention / Treatment
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.
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.
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

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

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.

Investigators

  • 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)

May 11, 2022

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

February 18, 2022

First Submitted That Met QC Criteria

March 8, 2022

First Posted (Actual)

March 17, 2022

Study Record Updates

Last Update Posted (Actual)

February 5, 2026

Last Update Submitted That Met QC Criteria

February 2, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

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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