Evaluating Changes in Synovial Fluid Before and After GAE for Knee Osteoarthritis (GAE-KOA)

Genicular Artery Embolization for Knee Osteoarthritis: Evaluation of the Correlation Between Subjective Symptom Response and Objective Measures of Inflammation

The goal of this clinical trial is to learn if genicular artery embolization (GAE) can improve knee pain and decrease inflammation in adults with knee osteoarthritis. The main question it aims to answer is:

- Does the GAE procedure improve knee pain and decrease inflammation?

Researchers will compare synovial fluid samples taken from the knee before and after the procedure.

Participants will:

• Have a contrast enhanced MRI before and after the procedure
• Complete performance-based measures before and after the procedure
• Complete questionnaires before and after the procedure

Study Overview

• Status: Recruiting
• Conditions: Knee Osteoarthritis
• Intervention / Treatment: Procedure: GAE procedure

• Study Type: Interventional
• Enrollment (Estimated): 46
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Shireen Shikak, BS; Phone Number: 720.848.6618; Email: shireen.shikak@cuanschutz.edu
• Study Contact Backup: Name: Tricia Luna, MS, RN; Phone Number: 720.848.6610; Email: patricia.luna@cuanschutz.edu

Study Locations

• United States
  • Colorado
    • Aurora, Colorado, United States, 80045
      • Recruiting
      • University of Colorado Anschutz Medical Campus
      • Contact: Shireen Shikak, BS; Phone Number: 720-848-6767
      • Principal Investigator: Leigh Casadaban, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 18 years
• Planned to undergo genicular artery embolization to treat knee osteoarthritis.
• Osteoarthritis on knee radiograph (Kellgren-Lawrence score 1-3) within the last 6 months
• Persistent moderate to severe knee pain (visual analog scale [VAS] >3) for at least 6 months
• Pain refractory or intolerant to conservative therapies (e.g. analgesia, exercise, weight-loss, joint injections, physical therapy)
• BMI < 35 kg / m2
• Stated willingness to comply with study procedures and availability for the duration of the study

Exclusion Criteria:

• Coagulation disturbances not normalized by medical treatment (INR >1.8 and platelets <50 x 10^9/L)
• Receiving medications for anticoagulation which cannot safely be held for the procedure (e.g ASA for 5 days, Lovenox for 24 hours, Eliquis for 4-6 days depending on creatinine clearance
• Allergy to iodinated contrast agents not responsive to steroid premedication regimen
• Active knee joint infection
• Acute knee injury with surgical indication (MRI evidence of acute fracture or ligamentous injury of the knee)
• Prior total or partial knee replacement in the subject knee
• Intra-articular steroid injection within 2 months
• Untreated lower extremity vascular arterial disease
• Untreated venous insufficiency
• Presence of medical condition with life expectancy less than 6 months
• Patients who have undergone previous lower extremity embolization
• Patients with renal insufficiency based on an estimated GFR<45 ml/min who are not already on hemodialysis
• Patients who are pregnant or intend to become pregnant within 6 months of the procedure
• American Society of Anesthesiologists classification > 3
• Less than 3 mm of synovial fluid in the lateral suprapatellar recess on MRI or US

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: GAE procedure; Participants undergoing the GAE procedure will have synovial fluid sampling, performance-based measures and contrast-enhanced MRI before and after the procedure.	Procedure: GAE procedure; Genicular artery embolization

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measure changes in KOOS score and synovial fluid biomarkers	To estimate the correlation between objective changes in synovial fluid biomarkers (IL-6, VEGF and MCP-1) and changes in subjective symptomatic response (KOOS) 3 months after treatment of knee osteoarthritis with GAE. KOOS is a validated knee osteoarthritis scoring system that involves five subscales: pain (9 questions), symptoms (7 questions), activities of daily living (17 questions), sport/recreation (5 questions), knee-related quality of life (4 questions). Trials demonstrate maximum symptomatic response to GAE at 3 months, and sustained improvement for at least 1-2 years. Improvement in KOOS reflects symptomatic response to treatment. This will determine whether changes in the local inflammatory environment in the knee synovium correlate with symptomatic response to GAE. This would also help elucidate whether the mechanism of action of GAE is likely attributable to inflammation.	3 months after GAE procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measure changes in synovial enhancement with contrast-enhanced MRI according to WORMS synovitis scores	The WORMS scoring system is a semi-quantitative assessment of 14 features found on knee MRI. The WORMS synovitis subscale is scored based on the distension of the joint capsule and is graded from 0 to 3 in terms of the estimated maximal distention of the synovial cavity with 0=normal, grade 1=<33% of maximum potential distention grade 2=33%-66% of maximum potential distention and grade 3=>66% of maximum potential distention WORMS will be used to determine changes in synovial fluid biomarkers pre-treatment and 3 months after treatment of knee osteoarthritis with GAE.	3 months after GAE procedure
Measure changes in synovial enhancement with contrast-enhanced MRI according to MOST grading system	The MRI will also be evaluated using the Multicenter Osteoarthritis Study grading system for synovitis. The Multicenter Osteoarthritis Study (MOST) grading system for knee synovitis is an alternative to the WORMS synovitis score and incorporates a larger range of grading. The higher the score, the worse the synovial inflammation. The scoring ranges from 0-13, with 0-4 for normal or equivocal synovitis, 5-8 for mild synovitis, 9-12 for moderate synovitis, and 13 or greater for severe synovitis.	3 months after GAE procedure
Measure changes in VAS scores	Patients will be given VAS questionnaires to give subjective responses to changes in pain levels and its effect on activities of daily living. VAS is calculated by scoring pain level between 0-100. This is asked verbally "How would you rate your pain in the affected knee?" These questionnaires will be given at time points: screening, 1 month after GAE, 3 months, 6 months and 12 months.	12 months after procedure
Measure changes in KOOS scores	The Knee Injury and Osteoarthritis Outcome Score involves five subscales: pain (9 questions), symptoms (7 questions), activities of daily living (17 questions), sport/recreation (5 questions), knee-related quality of life (4 questions). Patients will be given KOOS questionnaires to give subjective responses to changes in pain levels and its effect on activities of daily living. These questionnaires will be given at time points: screening, 1 month after GAE, 3 months, 6 months and 12 months.	12 months after procedure
Estimate correlation between objective measures to symptomatic response	To estimate the correlation between objective measures of knee pain or inflammation (performance-based measures, contrast-enhanced MRI synovitis scores) to symptomatic response (KOOS) 3 months after treatment of knee osteoarthritis with GAE. This may provide additional assurance in the form of objective measures of response in a disease that is known to have a strong placebo effect.	3 months after GAE procedure
Estimate correlation between changes in a larger set of synovial fluid biomarkers and changes in subjective scores	To estimate the correlation between changes in a larger set of synovial fluid biomarkers (54markers across inflammation, chemotaxis, angiogenesis, and immune system regulation pathways) and changes in subjective scores (KOOS) 3 months after treatment. This will further develop the interrogation of which microenvironment pathways in the knee synovium correlate with symptomatic response to GAE.	3 months after GAE procedure

Collaborators and Investigators

• Sponsor: University of Colorado, Denver
• Investigators: Principal Investigator: Leigh Casadaban, MD, University of Colorado, Denver

Study record dates

Study Major Dates

• Study Start (Actual): July 16, 2025
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): July 1, 2028

Study Registration Dates

• First Submitted: April 7, 2025
• First Submitted That Met QC Criteria: April 15, 2025
• First Posted (Actual): April 23, 2025

Study Record Updates

• Last Update Posted (Actual): March 24, 2026
• Last Update Submitted That Met QC Criteria: March 19, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: 24-1048

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No