Phenol Neurolysis Versus Local Anesthetic Plus Steroid Genicular Nerve Block in Knee Osteoarthritis

NCT07267039 | Active Not Recruiting

• 2 other identifiers: OMU-FTR-2025/44OMU-EC-2025-44
• Study Type: observational
• Target: 42
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Knee Osteoarthritis; Genicular Nerve Block

Keywords

Knee Osteoarthritis; Gonarthrosis; Genicular Nerve Block; Genicular Nerve Neurolysis; Phenol; Bupivacaine; Triamcinolone Acetonide

Outcome Measures

Primary Outcomes (1)

• 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.

  Baseline, 2 weeks, and 3 months after the intervention

Secondary Outcomes (5)

• Change in Function and Symptoms Measured by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)

  Baseline, 2 weeks, 3 months, and 6 months after the intervention

• Change in Knee Function Measured by Oxford Knee Score (OKS)

  Baseline, 2 weeks, 3 months, and 6 months after the intervention

• Change in Knee Range of Motion (ROM)

  Baseline, 2 weeks, 3 months, and 6 months after the intervention

• Change in Nonsteroidal Anti-inflammatory Drug (NSAID) Consumption

  Baseline to 2 weeks, 2 weeks to 3 months, and 3 to 6 months after the intervention

• Adverse Events Related to the Intervention

  Baseline through 6 months after the intervention

Study Arms (2)

Phenol Neurolysis

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

Local Anesthetic + Triamcinolone Acetonide Block

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

Interventions

Phenol Injection DRUG

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

Phenol Neurolysis

Bupivacaine + Triamcinolone Acetonide Injection DRUG

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

Local Anesthetic + Triamcinolone Acetonide Block

Eligibility Criteria

• Age: 40 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

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.

You may qualify if:

• Age ≥ 40 years
• Diagnosis of knee osteoarthritis (Kellgren-Lawrence grade 3-4) confirmed by radiographic evaluation
• Moderate to severe knee pain for at least 3 months (VAS ≥ 4)
• Inadequate response to conservative treatments (e.g., medications, physical therapy, exercise)
• Ability to provide informed consent

You may not qualify if:

• History of knee surgery (e.g., total knee arthroplasty) on the affected side
• Intra-articular injection (hyaluronic acid, corticosteroid, PRP, etc.) within the last 6 months
• Secondary arthritis (e.g., rheumatoid arthritis, gout, septic arthritis, trauma-related arthritis)
• Severe coagulopathy or current use of anticoagulant therapy contraindicating injection
• Local skin infection at the injection site
• Known allergy or contraindication to phenol, bupivacaine, or triamcinolone acetonide
• Severe uncontrolled systemic disease (e.g., advanced cardiac, hepatic, or renal failure)
• Pregnancy or breastfeeding

Sponsors & Collaborators

• Salim Sencar: lead

Study Sites (1)

Ondokuz Mayis University, Faculty of Medicine, Department of Physical Medicine and Rehabilitation

Samsun, 55139, Turkey (Türkiye)

Location

Related Publications (2)

• Risso RC, Ferraro LHC, Nouer Frederico T, Peng PWH, Luzo MV, Debieux P, Sakata RK. Chemical Ablation of Genicular Nerve with Phenol for Pain Relief in Patients with Knee Osteoarthritis: A Prospective Study. Pain Pract. 2021 Apr;21(4):438-444. doi: 10.1111/papr.12972. Epub 2020 Dec 29.

  PMID: 33277760 RESULT

• Shanahan EM, Robinson L, Lyne S, Woodman R, Cai F, Dissanayake K, Paddick K, Cheung G, Voyvodic F. Genicular Nerve Block for Pain Management in Patients With Knee Osteoarthritis: A Randomized Placebo-Controlled Trial. Arthritis Rheumatol. 2023 Feb;75(2):201-209. doi: 10.1002/art.42384. Epub 2022 Nov 11.

  PMID: 36369781 RESULT

Related Links

• American College of Rheumatology (ACR) Guideline for the Management of Osteoarthritis of the Knee
• National Institute for Health and Care Excellence (NICE) Guideline for Osteoarthritis: Care and Management

MeSH Terms

Conditions

Osteoarthritis, Knee

Interventions

Phenol; Bupivacaine; Triamcinolone Acetonide; Anesthetics, Local

Condition Hierarchy (Ancestors)

Osteoarthritis; Arthritis; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases

Intervention Hierarchy (Ancestors)

Phenols; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons; Organic Chemicals; Anilides; Amides; Aniline Compounds; Amines; Triamcinolone; Pregnadienes; Pregnanes; Steroids; Fused-Ring Compounds; Polycyclic Compounds; Steroids, Fluorinated; Anesthetics; Central Nervous System Depressants; Physiological Effects of Drugs; Pharmacologic Actions; Chemical Actions and Uses; Sensory System Agents; Peripheral Nervous System Agents; Central Nervous System Agents; Therapeutic Uses

Study Officials

• Bora UZUNER, MD (Medical Doctor)

  Ondokuz Mayis University, Faculty of Medicine, Department of Physical Medicine and Rehabilitation

  PRINCIPAL INVESTIGATOR

• Salim SENCAR, MD (Medical Doctor)

  Ondokuz Mayis University, Faculty of Medicine, Department of Physical Medicine and Rehabilitation

  STUDY DIRECTOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Resident Physician (Research Assistant), Department of Physical Medicine and Rehabilitation, Ondokuz Mayıs University Faculty of Medicine

Study Record Dates

• First Submitted: November 24, 2025
• First Posted: December 5, 2025
• Study Start: May 1, 2025
• Primary Completion: September 1, 2025
• Study Completion: January 1, 2026
• Last Updated: December 5, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)