Knee Osteoarthritis, Genicular Nerve Block
Conditions
Keywords
Knee Osteoarthritis, Gonarthrosis, Genicular Nerve Block, Genicular Nerve Neurolysis, Phenol, Bupivacaine, Triamcinolone Acetonide
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.
Detailed description
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.
Interventions
DRUGBupivacaine + Triamcinolone Acetonide Injection
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.
DRUGPhenol 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.
Sponsors
Salim Sencar
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
40 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 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
Exclusion criteria
* 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Pain Intensity Measured by Visual Analog Scale (VAS) | Baseline, 2 weeks, and 3 months after the intervention | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 | 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. |
| Change in Knee Function Measured by Oxford Knee Score (OKS) | Baseline, 2 weeks, 3 months, and 6 months after the intervention | 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. |
| Change in Knee Range of Motion (ROM) | Baseline, 2 weeks, 3 months, and 6 months after the intervention | 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. |
| 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 | 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. |
| Adverse Events Related to the Intervention | Baseline through 6 months after 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. |
Countries
Turkey (Türkiye)
Outcome results
None listed