An interventional study of Thermal Radiofrequency Ablation of the Genicular Nerves and Intra-articular Hyaluronic Acid in Knee Osteoarthritis and Chronic Knee Pain, sponsored by Hospital Universitari Joan XXIII de Tarragona.. Not yet recruiting at 1 site in Spain. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by Hospital Universitari Joan XXIII de Tarragona. · Not applicable, Interventional, and Treatment
Among 100 studies in Osteoarthritis, Knee with a site in Spain — 16 open to participants now, 19 under way, 3 of them phase 3. Osteoarthritis, Knee · Spain.
Among the 100 studies in Osteoarthritis, Knee with a site in Spain, this one is the 55th largest by planned enrollment of the 86 interventional ones, is one of 9 that started in 2026, is one of 47 with no phase, reaches primary completion later than 13 of the 18 other live ones, and was the 100th registered.
3,292 studies on the registry are indexed under Osteoarthritis, Knee; 623 are open to participants now.
This study's planned enrollment of 70 is close to the median of 68 across 2,714 interventional studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →16 of the 100 studies in Osteoarthritis, Knee with a site in Spain are open now, in 12 countries. Each count lists the studies.
Of the 382 Osteoarthritis, Knee studies recruiting now, 176 (46%) set no upper age limit and 113 (30%) stop at 75 or younger; 19 take children under 18; 39 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →100 studies; the count open now beside each. This study's row is marked.
First in 2000; this study’s year is marked. 9 started in 2026.
Median enrollment 100 across the 86 interventional studies, 153 across the 14 observational. Of the 71 that completed or were terminated, 19 (27%) have results posted.
43 of 100 have an industry lead sponsor. The 10 most frequent:
Hospital Universitari Joan XXIII de Tarragona. is the lead sponsor of 8 studies on the registry; 2 are open to participants now.
Hospital Universitari Joan XXIII de Tarragona. has 1 study filed under Osteoarthritis, Knee — fewer than ten, so there is no comparison to draw.
4 of the studies in Osteoarthritis, Knee with a site in Spain that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT06721897University of JaénEffectiveness of a Prehabilitation Program for Hip or Knee Arthroplasty Surgery. | 2026-11-30 |
| NCT07434011Universidad Complutense de MadridEfficacy of Artificial Intelligence-Assisted Therapeutic Exercise in Patients With Knee Osteoarthritis | 2027-03-15 |
| NCT07886697Universidad Rey Juan CarlosLow-Dose Radiotherapy for Painful Knee Osteoarthritis | 2027-06-30 |
| NCT07870967Universidad Católica San Antonio de MurciaUndenatured Type II Collagen for Knee Osteoarthritis Pain | 2027-07 |
Among the 100 studies in Osteoarthritis, Knee with a site in Spain, from their registry updates:
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:
Researchers will compare radiofrequency ablation with hyaluronic acid injection to see which treatment gives greater and longer-lasting pain relief.
Participants will:
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.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
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
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).
Single 6 ml intra-articular injection of high molecular weight hyaluronic acid into the index knee.
Change in Knee Pain During Movement (Visual Analogue Scale)
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.
Time frame: Baseline, 1, 3, 6 and 12 months after the intervention
Change in Knee Pain at Rest (Visual Analogue Scale)
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.
Time frame: Baseline, 1, 3, 6 and 12 months after the intervention
Change in Knee Function (WOMAC)
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.
Time frame: Baseline, 1, 3, 6 and 12 months after the intervention
Proportion of Participants Achieving the Minimal Clinically Important Difference in Pain
Percentage of participants with a reduction of at least 2 points from baseline in pain during movement (visual analogue scale, 0-10).
Time frame: 1, 3, 6 and 12 months after the intervention
Analgesic Consumption
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).
Time frame: Baseline, 1, 3, 6 and 12 months after the intervention
Number of Participants With Adverse Events
Adverse events related to the diagnostic block, radiofrequency ablation or hyaluronic acid injection, systematically recorded at each visit.
Time frame: Up to 12 months after the intervention
Retreatment or Rescue Treatment
Proportion of participants requiring retreatment, rescue treatment (including corticosteroid injection) or indication of total knee arthroplasty, and time to first retreatment or rescue treatment.
Time frame: Up to 12 months after the intervention
Health-Related Quality of Life (EQ-5D-5L)
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).
Time frame: Baseline, 6 and 12 months after the intervention
Rate of Negative Diagnostic Genicular Nerve Blocks
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.
Time frame: 4 hours after the diagnostic block
Patient Global Assessment
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.
Time frame: Baseline, 1, 3, 6 and 12 months after the intervention
Patient Global Impression of Change (PGIC)
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".
Time frame: 1, 3, 6 and 12 months after the intervention
Proportion of OMERACT-OARSI Responders
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.
Time frame: 1, 3, 6 and 12 months after the intervention
Plan to share: No — 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.
No publications or documents are linked to this record.
Start is estimated for Oct 2026; primary completion for May 2028, 19 months later.
Of 1,111 non-industry interventional studies with no phase under Osteoarthritis, Knee, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 36. This study's planned 19 months is close to that.
Counting every sponsor, half of 1,251 studies reached it within 18 months; a quarter within 8 and three quarters within 36.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Hospital Universitari Joan XXIII de Tarragona.