An observational study in Knee Osteoarthritis and Genicular Nerve Block, sponsored by Salim Sencar. Completed at 1 site in Turkey (Türkiye). Open to participants aged 40 Years and older. Per ClinicalTrials.gov, last updated 2026-08-18.
Sponsored by Salim Sencar · Observational
This study aims to evaluate two different ultrasound-guided procedures for patients with knee osteoarthritis (gonarthrosis) who did not benefit from conservative treatments. The first method is genicular nerve neurolysis with phenol, a chemical agent that blocks nerve signals and may reduce pain for a longer period. The second method is a genicular nerve block with local anesthetic (bupivacaine) and corticosteroid (triamcinolone acetonide), which is commonly used to relieve pain and inflammation.
A total of 42 patients are followed prospectively. Pain intensity is measured using the Visual Analog Scale (VAS), and functional outcomes are assessed with the WOMAC Index and Oxford Knee Score (OKS). Joint range of motion, need for pain medications, and possible side effects are also monitored.
The results will help to compare the effectiveness and safety of phenol neurolysis and triamcinolone acetonide-local anesthetic nerve block, and may guide future treatment choices for patients with knee osteoarthritis.
Knee osteoarthritis (gonarthrosis) is a major cause of chronic pain and disability. Patients who fail to respond to conservative treatments such as medications, physical therapy, and exercise often require interventional options for pain relief.
This prospective observational cohort study compares two ultrasound-guided procedures targeting the genicular nerves of the knee:
Genicular nerve neurolysis with phenol - phenol induces protein denaturation and Wallerian degeneration in nerve fibers, providing long-term analgesia.
Genicular nerve block with local anesthetic (bupivacaine) and corticosteroid (triamcinolone acetonide) - this combination offers immediate pain reduction from nerve blockade and potential prolonged relief due to the anti-inflammatory action of the steroid.
A total of 42 patients with Kellgren-Lawrence grade 3-4 knee osteoarthritis and moderate-to-severe pain (VAS ≥ 4 for ≥ 3 months) are prospectively followed. Interventions are performed under ultrasound guidance at the superomedial, superolateral, and inferomedial genicular nerves.
The primary outcome is change in pain severity (VAS). Secondary outcomes include functional improvement assessed by the WOMAC Index and Oxford Knee Score (OKS), joint range of motion, need for nonsteroidal anti-inflammatory drugs (NSAIDs), and procedure-related adverse events. Assessments are performed at baseline, 2 weeks, and 3 months post-procedure.
The study aims to provide comparative evidence on the effectiveness and safety of phenol neurolysis versus triamcinolone acetonide-local anesthetic block, helping to guide clinical practice in the management of knee osteoarthritis.
3,302 studies on the registry are indexed under Osteoarthritis, Knee; 608 are open to participants now.
This study's enrollment of 42 is below the median of 100 across 472 observational studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →This is the only study on the registry with Salim Sencar as lead sponsor.
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The study population consists of adult patients (≥40 years) diagnosed with moderate to severe knee osteoarthritis (Kellgren-Lawrence grade 3-4) who did not benefit from conservative treatments such as medications and physical therapy. A total of 42 patients are enrolled and treated at the Physical Medicine and Rehabilitation Department, Ondokuz Mayis University, Faculty of Medicine, Samsun, Turkey.
Exclusion Criteria:
Patients in this group receive ultrasound-guided genicular nerve neurolysis. Using a 22G, 50 mm needle under ultrasound guidance, injections are performed at the superomedial, superolateral, and inferomedial genicular nerves. At each site, 2 mL of 6% phenol is injected to achieve chemical neurolysis and long-term pain relief.
Drug: Phenol Injection
Patients in this group receive ultrasound-guided genicular nerve block. At the same three target nerves (superomedial, superolateral, inferomedial), 2 mL of a mixture containing 0.25% bupivacaine and 20 mg triamcinolone acetonide is injected at each site. This combination provides nerve blockade with additional anti-inflammatory effect from the corticosteroid.
Drug: Bupivacaine + Triamcinolone Acetonide Injection
Ultrasound-guided genicular nerve neurolysis performed at the superomedial, superolateral, and inferomedial genicular nerves. A 22G, 50 mm insulated needle is placed under ultrasound guidance, and 2 mL of 6% phenol is injected at each target site for chemical neurolysis.
Also known as: Phenol Neurolysis
Ultrasound-guided genicular nerve block performed at the superomedial, superolateral, and inferomedial genicular nerves. At each site, 2 mL of a solution containing 0.25% bupivacaine and 20 mg triamcinolone acetonide is injected using a 22G, 50 mm insulated needle. This provides both local anesthetic and anti-inflammatory effects.
Also known as: Local Anesthetic + Steroid Block
Change in Pain Intensity Measured by Visual Analog Scale (VAS)
Pain severity will be evaluated using the Visual Analog Scale (VAS; 0-10 cm), where 0 indicates no pain and 10 indicates the worst imaginable pain. Patients will rate their knee pain at rest and during activity. The main outcome is the change in VAS score from baseline to follow-up assessments.
Time frame: Baseline, 2 weeks, and 3 months after the intervention
Change in Function and Symptoms Measured by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
The WOMAC Index will be used to assess three domains: pain, stiffness, and physical function in patients with knee osteoarthritis. Scores will be calculated according to the standard WOMAC scoring system, with higher scores indicating worse symptoms. The outcome is the change in WOMAC score from baseline to follow-up.
Time frame: Baseline, 2 weeks, 3 months, and 6 months after the intervention
Change in Knee Function Measured by Oxford Knee Score (OKS)
he Oxford Knee Score (OKS) is a 12-item patient-reported outcome measure evaluating pain and physical function related to the knee. Scores range from 0 to 48, with higher scores indicating better function. The outcome is the change in OKS from baseline to follow-up.
Time frame: Baseline, 2 weeks, 3 months, and 6 months after the intervention
Change in Knee Range of Motion (ROM)
Knee joint range of motion, including flexion and extension, will be measured using a goniometer by a blinded assessor. Both active and passive ROM will be recorded. The outcome is the change in degrees of movement compared to baseline.
Time frame: Baseline, 2 weeks, 3 months, and 6 months after the intervention
Change in Nonsteroidal Anti-inflammatory Drug (NSAID) Consumption
The number of NSAID doses consumed by participants will be recorded throughout the follow-up period. The outcome measure is the total NSAID use and change compared to baseline.
Time frame: Baseline to 2 weeks, 2 weeks to 3 months, and 3 to 6 months after the intervention
Adverse Events Related to the Intervention
Any adverse events possibly or probably related to the intervention will be recorded, including local complications (infection, bleeding, hematoma, skin changes) or systemic side effects.
Time frame: Baseline through 6 months after the intervention
Plan to share: No — Individual participant data (IPD) will not be shared because this is a single-center thesis study with a small number of patients, and data are not intended for public repositories. Only aggregated, anonymized results will be published.
This study is completed, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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