Genicular Artery Embolization for Reducing Pain in Medically Refractory Symptomatic Knee Osteoarthritis

Inclusion Criteria:

* Patients aged 40-80
* Bilateral or unilateral knee pain attributed to osteoarthritis (treat the knee with greater pain-if equal, patient chooses)
* Grade 2-4 osteoarthritis on standing weight-bearing knee radiographs per the Kellgren-Lawrence grading scale
* Knee pain \> 6 months, refractory to conservative non-operative management, and scored ≥ 4 on Visual Analog Scale (VAS) (e.g., rest, activity modification, weight control, bracing, supervised physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, oral opiates, intra-articular hyaluronic acid, PRP, stem cells, and/or oral/injectable corticosteroids)
* Refusal of intra-articular corticosteroid injection

Exclusion Criteria:

* Active malignancy
* Active infection of the affected knee
* Corticosteroid injection of the affected knee within 3 months of enrollment
* Rheumatoid arthritis or other seronegative arthropathy
* Previous surgery of the affected knee (e.g., meniscus repair, meniscectomy, anterior cruciate ligament (ACL)/posterior cruciate ligament (PCL) reconstruction, chondroplasty, microfracture, loose-body removal, synovectomy, lateral release, patellar/quadriceps tendon repair, total or partial knee replacement, osteotomy, cartilage transplant), except diagnostic arthroscopy
* Grade 0-1 osteoarthritis per Kellgren-Lawrence grading scale of the affected knee
* Pregnancy or expected pregnancy
* GFR \< 60 mL/min/1.73 m²
* Anaphylactic reaction to iodinated contrast
* Moderate to severe pain in other ipsilateral lower-limb joints (ankle, hip) with VAS \> 4
* Body weight \> 400 lbs (unsafe for angiography)
* Peripheral arterial disease of the treated extremity (Rutherford Grade 2 or greater)
* Type 1 diabetes mellitus
* Long-acting corticosteroid use within 6 months (3 months for short-acting)
* History or other evidence of acute kidney injury (AKI)
* History of reaction to contrast media, bronchial asthma, or allergic disorders
* History of hypersensitivity to gadolinium-based contrast agents (GBCAs)
* Chronic widespread generalized pain \>4 on VAS pain scale, including neuropathic pain
* Major depressive disorder within 2 years before screening
* Other severe psychiatric disorder (e.g., schizophrenia, bipolar disorder)
* Suicide attempt or suicidal behavior within 30 days before screening
* Diagnosis of fibromyalgia
* Considering total knee replacement in the next year
* Any other condition, unwillingness, or inability that, in the investigator's opinion, could jeopardize the subject's safety or protocol compliance