The genicular artery embolization vs nerve ablation intervention (GENI) knee OA study is a three-arm randomized controlled trial to evaluate symptoms of knee osteoarthritis (OA) in patients after receiving one of three interventions: sham procedure, geniculate artery embolization (GAE) or genicular nerve phenol nerve ablation (PNA).

The main question[s] the study aims to answer are:

• Does GAE or genicular nerve PNA result in OA symptom alleviation compared to sham procedure?
• Are there molecular or imaging biomarkers that aid in predicting treatment response for GAE or genicular nerve PNA?

Subjects (N=150) patients with knee OA, resistant to non-surgical treatment for at least 3 months will be randomized 1:1:1 to either after GAE, genicular nerve PNA or sham procedure. Clinical outcomes will be measured using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and 11-point numerical rating scale (NRS) for pain completed at baseline, 1 month, 3 months, and 6 months and then every 6 months for either two years or until the time of total knee arthroplasty (TKA) surgery.

Osteoarthritis (OA) of the knee is a common and debilitating disease. Advanced disease can be treated with total knee arthroplasty (TKA), however knee OA that is either resistant to non-surgical options, or where surgical options are not available, represents a specific management challenge. Genicular artery embolization (GAE) and genicular nerve phenol nerve ablation (PNA) have emerged as potentially successful treatments to reduce knee OA symptoms, however, to date no randomized controlled trials have been completed comparing the two procedures.

The purpose of this study is to compare the clinical outcomes of GAE to genicular nerve PNA for chronic knee pain in patients with knee OA. Further, molecular biomarkers and imaging will be taken pre- and post-procedure to evaluate if immune-mediated neuroinflammation and angiogenesis can be helpful in predicting treatment response.

This single center randomized controlled trial will be conducted to determine if GAE, genicular nerve PNA, or sham procedure is associated with a clinically significant alleviation of knee OA symptoms. The investigators aim to include 150 participants in this study over the course of 24 months randomized 1:1:1 to receive either GAE, genicular nerve PNA, or sham procedure.

After eligibility is confirmed and consent is obtained, a baseline assessment will be conducted including baseline Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and 11-point numerical rating scale (NRS) for pain scores. Participants will receive a knee 3T MRI with gadolinium contrast and 0.5 - 5 mL of synovial fluid will be aspirated for baseline analysis. Participants will receive Fitbit motion trackers to quantify activity levels throughout the study.

Study procedures will be performed by either a qualified Interventional Radiologist or fellowship-trained Anesthesiologist, depending on which study arm subjects randomized to.

Approximately 3 months after the procedure, repeat WOMAC and NRS scores will be obtained, in addition to repeat 3T MRI with gadolinium contrast and knee aspirate of 0.5 - 5 mL of synovial fluid. Additional questions pertaining to knee-specific analgesia use, adverse events from the procedure, or any concerns will be addressed and noted at this time.

Participants will be followed up by phone by a blinded member of the research team 6 months after the procedure and every 6 months thereafter for 2 years or until the time of TKA surgery (if applicable). During phone calls, questions relating to knee-specific analgesia use will be asked and repeat WOMAC and NRS scores will be acquired.

Data for this study includes: demographic information, knee-specific analgesia use, which procedure was performed, knee 3T MRI with gadolinium contrast, WOMAC scores, NRS pain scores, knee synovial fluid cytokine/chemokine biomarker analysis, and procedure-specific adverse events.

Inclusion Criteria:

• Age > 40 years
• Able to provide informed consent
• Knee pain due to osteoarthritis for at least 6 months
• Pain refractory to conservative therapies (oral medication, or physical therapy, or activity modification) for at least 3 months with a desire for TKA
• Candidate for TKA at Hotel Dieu Hospital Site
• Able to comply with all treatments and protocol follow-up visits

Exclusion Criteria:

• Current local infection
• Systemic or joint centered inflammatory disease (ie rheumatoid arthritis, Lupus, multiple sclerosis or other autoimmune diseases)
• Current use of systemic immunosuppression therapy
• Known lower extremity vascular disease or lower extremity symptoms thought to be secondary to arterial vascular disease (eg claudication, ischemic rest pain)
• Irreversible coagulopathy
• Renal dysfunction as defined by GFR (eGFR) of <30 obtained within the past 60 days
• Contraindication for MR Imaging (such as claustrophobia, metallic fragment or foreign bones, implants or prosthesis)
• IV CT and/or MRI contrast allergy characterized by anaphylaxis or anaphylactoid reactions
• Pregnancy or women of childbearing potential not currently on a medically acceptable method of birth control