GonarthrosisNCT07805161
Bipolar RFA Versus Phenol Neurolysis for Knee Osteoarthritis Pain
A study testing Phenol Chemical Neurolysis and Ultrasound-Guided Bipolar Radiofrequency Ablation in people with Gonarthrosis, run by Saglik Bilimleri Universitesi at 1 site in Turkey (Türkiye).
Trial summary
This prospective observational comparative study evaluates the analgesic efficacy and safety of ultrasound-guided bipolar radiofrequency ablation (BPRFA) versus phenol chemical neurolysis (PCN) of the genicular nerves in patients with chronic knee osteoarthritis (gonarthrosis) refractory to conservative treatment. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Gonarthrosis
- What is being tested?
- Phenol Chemical Neurolysis and Ultrasound-Guided Bipolar Radiofrequency Ablation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 69 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Aug 2024to 1 Jun 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18 to 75 years
- Unilateral moderate-to-severe knee pain due to gonarthrosis
- Numeric Rating Scale (NRS) score ≥6
- Knee pain lasting longer than 6 months
- Radiological diagnosis of knee osteoarthritis, Kellgren-Lawrence grade 2-4
- Failure of conservative treatments, including analgesic medications, physical therapy, or intra-articular injections
- At least 50% pain relief after diagnostic genicular nerve block
- Ability to provide written informed consent
Who cannot join
- Knee pain due to causes other than osteoarthritis, such as fracture, trauma, spinal disorder, or inflammatory arthritis
- Previous knee surgery
- Knee joint effusion detected on physical examination or ultrasound
- Cognitive impairment
- Hepatic or renal failure
- Severe psychiatric disorder
Show all 11Show fewer
- Local or systemic infection
- Coagulopathy
- Current use of antiplatelet or anticoagulant therapy
- Presence of a pacemaker
- Intra-articular injection or interventional knee procedure within the previous 6 months
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
University Of Health Sciences, Gulhane School Of Medicine, Department Of Algology
Ankara, Etlik, 06010
About this study
Official title: Observational Comparative Study on the Analgesic Outcomes of Bipolar Radiofrequency Ablation Versus Phenol Neurolysis of the Genicular Nerves in Gonarthrosis
This prospective observational comparative study evaluates the analgesic efficacy and safety of ultrasound-guided bipolar radiofrequency ablation (BPRFA) versus phenol chemical neurolysis (PCN) of the genicular nerves in patients with chronic knee osteoarthritis (gonarthrosis) refractory to conservative treatment.
Patients with moderate-to-severe chronic knee pain who demonstrate significant pain relief following diagnostic genicular nerve block undergo either BPRFA or PCN targeting the superior medial, superior lateral, and inferior medial genicular nerves under ultrasound guidance. Pain intensity and functional outcomes are assessed using the Numeric Rating Scale (NRS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and during follow-up evaluations at 4, 12, and 24 weeks after treatment.
The study aims to compare pain reduction, functional improvement, responder rates, and procedure-related adverse events between the two treatment modalities.
Read the detailed description
Knee osteoarthritis (gonarthrosis) is a common cause of chronic knee pain and functional limitation, especially in older adults. Although conservative treatments such as physical therapy, oral analgesics, and intra-articular injections are commonly used, many patients continue to experience persistent pain and reduced quality of life. In recent years, minimally invasive genicular nerve interventions have become important alternatives for patients who do not achieve adequate benefit from conservative management or are not suitable candidates for surgery.
Radiofrequency ablation (RFA) of the genicular nerves has been shown to reduce pain and improve function in patients with chronic knee osteoarthritis. Bipolar radiofrequency ablation (BPRFA), which uses two closely positioned radiofrequency cannulas, may create larger lesions and provide broader denervation compared with conventional monopolar techniques. Phenol chemical neurolysis (PCN) is another minimally invasive treatment option that provides chemical denervation of the genicular nerves and may represent a simpler and more cost-effective alternative. However, concerns remain regarding the potential for unintended spread of phenol and procedure-related complications.
The aim of this prospective observational comparative study is to compare the analgesic efficacy, functional outcomes, and safety profiles of ultrasound-guided BPRFA and PCN in patients with chronic knee osteoarthritis who are refractory to conservative treatment. Patients with chronic moderate-to-severe unilateral knee pain and radiologically confirmed osteoarthritis first undergo diagnostic genicular nerve block under ultrasound guidance. Patients who achieve significant pain relief after the diagnostic block subsequently receive either BPRFA or PCN as part of routine clinical practice.
Pain severity and functional status are evaluated using the Numeric Rating Scale (NRS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and during follow-up visits at 4, 12, and 24 weeks after treatment. The study also compares treatment response rates and procedure-related adverse events between the two interventions.
- Conditions
- Gonarthrosis
- Being tested
- Phenol Chemical Neurolysis, Ultrasound-Guided Bipolar Radiofrequency Ablation
- Keywords
- knee, gonarthrosis, radiofrequency ablation, phenol, ultrasound, genicular nerves
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Phenol Chemical NeurolysisProcedure or surgery
Ultrasound-guided phenol neurolysis was performed targeting the superior medial, superior lateral, and inferior medial genicular nerves. Following confirmation of needle placement, 2 mL of 8% phenol was injected around each targeted genicular nerve.
Ultrasound-Guided Bipolar Radiofrequency AblationProcedure or surgery
Ultrasound-guided bipolar radiofrequency ablation was performed using two parallel radiofrequency cannulas placed within 1 cm of each other targeting the superior medial, superior lateral, and inferior medial genicular nerves. Radiofrequency ablation was applied at 80°C for 90 seconds following sensory and motor stimulation testing.
| Study group | Role | What they receive |
|---|---|---|
| Phenol Chemical Neurolysis | Active comparator | Patients undergo ultrasound-guided phenol chemical neurolysis of the superior medial, superior lateral, and inferior medial genicular nerves following a positive diagnostic genicular nerve block. Receives: Procedure: Phenol Chemical Neurolysis |
| Bipolar Radiofrequency Ablation | Active comparator | Patients undergo ultrasound-guided bipolar radiofrequency ablation of the superior medial, superior lateral, and inferior medial genicular nerves following a positive diagnostic genicular nerve block. Receives: Procedure: Ultrasound-Guided Bipolar Radiofrequency Ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Pain Intensity
Pain intensity was assessed using the Numeric Rating Scale (NRS). Changes in NRS scores from baseline were evaluated after ultrasound-guided bipolar radiofrequency ablation and phenol chemical neurolysis of the genicular nerves.
Measured: Baseline, 4 weeks, 12 weeks, and 24 weeks
Secondary outcomes (3)
Functional improvement
Functional outcomes and quality of life were evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), including total, pain, stiffness, and function subscale scores.
Measured: Baseline, 4 weeks, 12 weeks, and 24 weeks
Proportion of Patients Achieving ≥50% Reduction in NRS Scores
Treatment response was defined as a reduction of at least 50% in Numeric Rating Scale (NRS) scores compared with baseline values following treatment.
Measured: 12 weeks and 24 weeks
Procedure-related complications
The incidence of procedure-related adverse events and complications was recorded throughout the follow-up period.
Measured: Up to 24 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Sep 2026
- Study start1 Aug 2024
- Primary completion1 Jun 2025
- Study completion1 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for GonarthrosisStudies of the same condition, open and under way.
- More trials run by Saglik Bilimleri UniversitesiThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 69 participants (actual)
Sponsor and investigators
- Lead sponsor
- Saglik Bilimleri Universitesi
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Alp Eren Celenlioglu, MD./Assoc. Prof., Study director, Department of Algology, University of Health Sciences Gulhane Training and Research Hospital, Ankara, Turkiye
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07805161
- Sponsor's protocol ID
- GEAH-ALGO-GENI-FEN-BRF-2025-02
- Other IDs
- AES-EK1-2024-0046
- Status last verified
- May 2026
- First submitted
- 5 May 2026
- Last updated
- 4 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Observational Comparative Study on the Analgesic Outcomes of Bipolar Radiofrequency Ablation Versus Phenol Neurolysis of the Genicular Nerves in Gonarthrosis
- ClinicalTrials.gov ID
- NCT07805161
- Acronym / sponsor ID
- GEAH-ALGO-GENI-FEN-BRF-2025-02
- Conditions
- Gonarthrosis
- Keywords
- knee, gonarthrosis, radiofrequency ablation, phenol, ultrasound, genicular nerves
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 69 participants (actual)
- Lead sponsor
- Saglik Bilimleri UniversitesiUniversity, hospital or other
- Study start
- 1 Aug 2024 (actual)
- Primary completion
- 1 Jun 2025 (actual)
- Study completion
- 1 Jun 2025 (actual)
- First posted
- 4 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective observational comparative study evaluates the analgesic efficacy and safety of ultrasound-guided bipolar radiofrequency ablation (BPRFA) versus phenol chemical neurolysis (PCN) of the genicular nerves in patients with chronic knee osteoarthritis (gonarthrosis) refractory to conservative treatment.
Patients with moderate-to-severe chronic knee pain who demonstrate significant pain relief following diagnostic genicular nerve block undergo either BPRFA or PCN targeting the superior medial, superior lateral, and inferior medial genicular nerves under ultrasound guidance. Pain intensity and functional outcomes are assessed using the Numeric Rating Scale (NRS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and during follow-up evaluations at 4, 12, and 24 weeks after treatment.
The study aims to compare pain reduction, functional improvement, responder rates, and procedure-related adverse events between the two treatment modalities.
Detailed description
Knee osteoarthritis (gonarthrosis) is a common cause of chronic knee pain and functional limitation, especially in older adults. Although conservative treatments such as physical therapy, oral analgesics, and intra-articular injections are commonly used, many patients continue to experience persistent pain and reduced quality of life. In recent years, minimally invasive genicular nerve interventions have become important alternatives for patients who do not achieve adequate benefit from conservative management or are not suitable candidates for surgery.
Radiofrequency ablation (RFA) of the genicular nerves has been shown to reduce pain and improve function in patients with chronic knee osteoarthritis. Bipolar radiofrequency ablation (BPRFA), which uses two closely positioned radiofrequency cannulas, may create larger lesions and provide broader denervation compared with conventional monopolar techniques. Phenol chemical neurolysis (PCN) is another minimally invasive treatment option that provides chemical denervation of the genicular nerves and may represent a simpler and more cost-effective alternative. However, concerns remain regarding the potential for unintended spread of phenol and procedure-related complications.
The aim of this prospective observational comparative study is to compare the analgesic efficacy, functional outcomes, and safety profiles of ultrasound-guided BPRFA and PCN in patients with chronic knee osteoarthritis who are refractory to conservative treatment. Patients with chronic moderate-to-severe unilateral knee pain and radiologically confirmed osteoarthritis first undergo diagnostic genicular nerve block under ultrasound guidance. Patients who achieve significant pain relief after the diagnostic block subsequently receive either BPRFA or PCN as part of routine clinical practice.
Pain severity and functional status are evaluated using the Numeric Rating Scale (NRS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and during follow-up visits at 4, 12, and 24 weeks after treatment. The study also compares treatment response rates and procedure-related adverse events between the two interventions.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Phenol Chemical Neurolysis | Active comparator | Procedure: Phenol Chemical NeurolysisPatients undergo ultrasound-guided phenol chemical neurolysis of the superior medial, superior lateral, and inferior medial genicular nerves following a positive diagnostic genicular nerve block. |
| Bipolar Radiofrequency Ablation | Active comparator | Procedure: Ultrasound-Guided Bipolar Radiofrequency AblationPatients undergo ultrasound-guided bipolar radiofrequency ablation of the superior medial, superior lateral, and inferior medial genicular nerves following a positive diagnostic genicular nerve block. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Adults aged 18 to 75 years
- Unilateral moderate-to-severe knee pain due to gonarthrosis
- Numeric Rating Scale (NRS) score ≥6
- Knee pain lasting longer than 6 months
- Radiological diagnosis of knee osteoarthritis, Kellgren-Lawrence grade 2-4
Key exclusion criteria (11 listed)
- Knee pain due to causes other than osteoarthritis, such as fracture, trauma, spinal disorder, or inflammatory arthritis
- Previous knee surgery
- Knee joint effusion detected on physical examination or ultrasound
- Cognitive impairment
- Hepatic or renal failure
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Phenol Chemical NeurolysisUltrasound-guided phenol neurolysis was performed targeting the superior medial, superior lateral, and inferior medial genicular nerves. Following confirmation of needle placement, 2 mL of 8% phenol was injected around each targeted genicular nerve. | Procedure or surgery | Phenol Chemical Neurolysis |
| Ultrasound-Guided Bipolar Radiofrequency AblationUltrasound-guided bipolar radiofrequency ablation was performed using two parallel radiofrequency cannulas placed within 1 cm of each other targeting the superior medial, superior lateral, and inferior medial genicular nerves. Radiofrequency ablation was applied at 80°C for 90 seconds following sensory and motor stimulation testing. | Procedure or surgery | Bipolar Radiofrequency Ablation |
Primary outcome
Change in Pain Intensity
Time frame: Baseline, 4 weeks, 12 weeks, and 24 weeks
Pain intensity was assessed using the Numeric Rating Scale (NRS). Changes in NRS scores from baseline were evaluated after ultrasound-guided bipolar radiofrequency ablation and phenol chemical neurolysis of the genicular nerves.
3 secondary outcomes
Functional improvement
Time frame: Baseline, 4 weeks, 12 weeks, and 24 weeks
Proportion of Patients Achieving ≥50% Reduction in NRS Scores
Time frame: 12 weeks and 24 weeks
Procedure-related complications
Time frame: Up to 24 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Sep 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Alp Eren Celenlioglu, MD./Assoc. Prof. study director
Department of Algology, University of Health Sciences Gulhane Training and Research Hospital, Ankara, Turkiye
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Phenol Chemical Neurolysis and Ultrasound-Guided Bipolar Radiofrequency Ablation in people with Gonarthrosis, run by Saglik Bilimleri Universitesi at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Pain Intensity (time frame: Baseline, 4 weeks, 12 weeks, and 24 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Sep 2026.