TcPRF for Knee Osteoarthritis

January 10, 2026 updated by: Martina Rekatsina, National and Kapodistrian University of Athens

Randomized Double-Blind Study to Evaluate the Efficacy of Transcutaneous Pulsed Radiofrequency (PRF) Treatment for Knee Pain

Objectives

  • Primary Objective: To evaluate the efficacy of transcutaneous PRF treatment in reducing knee pain compared to a sham intervention
  • Secondary Objectives: To assess the improvement in functional outcomes and patient satisfaction following PRF treatment.

Study Design

  • Type: Randomized, double-blind, sham-controlled study.
  • Duration: 6 months
  • Study Population: Adults aged 40-75 years with chronic knee pain (lasting ≥ 6 months) due to osteoarthritis (OA).
  • How many patients in each group: 25 patients in each group (according to Janssens et al, 2024) Inclusion Criteria
  • Diagnosed with knee osteoarthritis according to NICE criteria.
  • Chronic knee pain (Visual Analogue Scale [VAS] ≥ 4).
  • Failure to respond adequately to conventional treatments (e.g., NSAIDs, physical therapy).
  • Willingness to comply with study procedures. Exclusion Criteria
  • Previous PRF/RF treatment for knee pain.
  • Hyaluronic acid injection for knee pain in the past 6 months
  • Knee surgery within the last 6 months.
  • Severe cardiovascular, neurological, or psychiatric conditions.
  • Active systemic infections or local skin infections at the knee.
  • Pregnancy or lactation.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

Randomization and Blinding

  • Randomization: Participants will be randomly assigned to one of two groups: PRF treatment or sham.
  • Blinding: Both participants and investigators will be blinded to the treatment allocation. The device used for PRF treatment will have an identical appearance for both the active and sham groups, but the sham electrode will not deliver active treatment.

Intervention Both groups will receive disposable electrodes on either side of the knee: one skin electrode on the inside and one on the outside of the knee.

  • PRF Group: Participants will receive PRF treatment using a specific protocol (e.g., 3 Hz, 5 ms, 15 minutes, 3 sessions with 1 week and 3 weeks interval). The output will be adjusted according to the distance between electrodes in cm. This will be between 0.7A (circumference 23cm) and 1.4A for 38cm (Spring 2, Clinical Guidelines, Table 1)
  • Sham Group: Participants will receive a sham treatment using a device identical in appearance but without delivering the actual PRF therapy.

Outcome Measures Primary Outcome • Pain Reduction: Measured using the NRS (numerical rating scale) at baseline, immediately after treatment, and at follow-up intervals (2 weeks, 4 weeks, 8 weeks, 12 weeks).

Secondary Outcomes

  • Functional Improvement: Assessed using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores.
  • Patient Satisfaction: Measured using a Likert scale for overall satisfaction with treatment.
  • Global Assessment: Patient's global assessment of change in pain and function.
  • Medication reduction Sample Size Calculation
  • Estimate: Based on previous studies and expected effect size, calculate the necessary sample size to achieve a power of 80% and a significance level of 0.05. The sample size must account for potential dropouts.

Data Collection and Management

  • Data will be collected at baseline, post-treatment, and during follow-up visits.
  • Use electronic case report forms (eCRFs) for data entry.
  • Ensure the security and confidentiality of participant data. Statistical Analysis
  • Primary Analysis: Compare the mean change in VAS scores between the PRF and sham groups using an independent t-test or ANCOVA, adjusting for baseline values.
  • Secondary Analysis: Compare changes in WOMAC scores and patient satisfaction between groups using similar statistical methods.
  • Responder Analysis: Define responders as those with ≥30% reduction in VAS scores from baseline and compare proportions between groups using a chi-square test.
  • Intention-to-Treat (ITT) Analysis: Include all randomized participants in the analysis based on the treatment they were allocated, regardless of whether they completed the study.

Ethical Considerations

  • Obtain informed consent from all participants.
  • Ethical approval from a recognized Institutional Review Board (IRB) is required.
  • Ensure that participants can withdraw at any time without affecting their standard care.

Monitoring and Safety

  • Adverse Events: Monitor and record all adverse events during the study.
  • Data Safety Monitoring Board (DSMB): Establish a DSMB to review safety data periodically.

Dissemination of Results

• Results will be published in a peer-reviewed journal and presented at relevant conferences within a year after results are known. Data will be reported according to CONSORT guidelines.

Timeline

  • Recruitment Period: 3 months
  • Intervention Period: 4 weeks
  • Follow-up Period: 3 and 6 months
  • Data Analysis and Reporting: 3 months after study completion.

Study Type

Interventional

Enrollment (Estimated)

50

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

  • Greece
      • Athens, Greece
        • ARETAIEION University Hospital

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria

  • Diagnosed with knee osteoarthritis according to NICE criteria.
  • Chronic knee pain (Visual Analogue Scale [VAS] ≥ 4).
  • Failure to respond adequately to conventional treatments (e.g., NSAIDs, physical therapy).
  • Willingness to comply with study procedures. Exclusion Criteria
  • Previous PRF/RF treatment for knee pain.
  • Hyaluronic acid injection for knee pain in the past 6 months
  • Knee surgery within the last 6 months.
  • Severe cardiovascular, neurological, or psychiatric conditions.
  • Active systemic infections or local skin infections at the knee.
  • Pregnancy or lactation.

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: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: TcPRF
Transcutaneous pulsed RF -connected to treatment mode of the spring pulsed rf generator
Device: Transcutaneous Pulsed Radiofrequency (PRF) Treatment for Knee Pain
application of TcPRF patches
Sham Comparator: TcPRF sham
sham of transcutaneus pRF- connected to demo mode of the spring pulsed rf generator
Device: sham treatment of pulsed rf on knee
Transdermal patch will be connected to demo mode of the spring pulsed rf generator. no treatment will be given

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pain Reduction
Time Frame: 12 weeks
Measured using the NRS (numerical rating scale) at baseline, immediately after treatment, and at follow-up intervals (2 weeks, 4 weeks, 8 weeks, 12 weeks).
12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Functional Improvement
Time Frame: 12 weeks
Assessed using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores.
12 weeks
• Patient Satisfaction
Time Frame: 12 weeks
Measured using a Likert scale for overall satisfaction with treatment.
12 weeks

Collaborators and Investigators

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

Sponsor

National and Kapodistrian University of Athens

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)

January 15, 2026

Primary Completion (Estimated)

March 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

January 10, 2026

First Submitted That Met QC Criteria

January 10, 2026

First Posted (Actual)

January 20, 2026

Study Record Updates

Last Update Posted (Actual)

January 20, 2026

Last Update Submitted That Met QC Criteria

January 10, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 695/24-07-2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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