Intervention: Kenalog
Trial phase: Phase 4
SMILES: CC1(C)OC2CC3C4CCC5=CC(=O)C=CC5(C)C4(F)C(O)CC3(C)C2(C(=O)CO)O1
Sex: All
Age groups: Adult | Older Adult
Healthy volunteers: No
Participants at risk: 70
Group description: 32 mg Zilretta in a 5ml diluent for each knee, per manufacturer guidelines

Zilretta: Zilretta (triamcinolone acetonide extended-release injectable suspension) is indicated as an intra-articular injection for the management of pain due to knee osteoarthritis.
Eligibility criteria:
Inclusion Criteria:

Men and women age 30 years or older with symptomatic bilateral knee OA
Symptomatic knee OA will be defined as the presence of a definite osteophyte or joint space narrowing (KL Grade ≥2) on posteroanterior (PA) fixed flexion knee radiographs in subjects limited by bilateral pain rated on a Numerical Rating Scale as ≥ 4/10 on more than half of the days over the past month. Radiographic change must be visible at standard image size, irrespective of capability to detect more subtle changes through digital enhancement.
Bilateral knee symptoms for ≥ 3 months prior to screening
Has undergone at least one prior conservative osteoarthritis treatment (e.g. Physical therapy, analgesics)
Body Mass Index ≤ 41 kg/m2
Ambulatory
Willing and able to comply with the study procedures and visit schedules and ability to follow verbal and written instructions.
Willingness to abstain from the use of protocol-restricted medications during the study after signing informed consent and also willing to abstain from use of all analgesics other than acetaminophen 1 week prior to beginning of treatment.

Exclusion Criteria:

Current consumption of more than 14 alcoholic drinks per week
Clinical signs and symptoms of active knee infection or crystal disease of either knee within 1 month of screening
Diagnosed with rheumatoid arthritis, Reiter's syndrome, psoriatic arthritis, gout, ankylosing spondylitis, or arthritis secondary to other inflammatory diseases; HIV, viral hepatitis; chondrocalcinosis, Paget's disease, or villonodular synovitis
Diagnosed with leukemia, known presence of metastatic malignant cells, or ongoing or planned chemotherapeutic treatment.
A gout attack in the past 2 years.
Diseases of the spine, hip or other lower extremity joints judged by the investigator to be contributing to the pain in either knee (i.e. sciatica, nerve pain, hip OA). Note: Patients with hip replacement in either hip may be enrolled provided there is sufficient pain relief after hip replacement that analgesics are not required.
Untreated symptomatic injury of either knee (e.g., acute traumatic injury, anterior cruciate ligament injury, clinically symptomatic meniscus injury characterized by a mechanical issue such as locking or catching).
Uncontrolled diabetes (HbA1c >7.2)
Women who report pregnancy or childbearing potential and not using acceptable contraceptive measures (oral contraceptive, long acting reversible contraceptive therapy) (due to the potential for change in body mass and distribution to alter knee symptoms over the period of follow-up).
Presence of surgical hardware or other foreign body intended to treat arthritis or cartilage-related pathology in either knee.
Arthroscopy or open surgery of either knee within 6 months of screening.
Planned/anticipated surgery of either knee during the study period.
Use of systemic immunosuppressant within 6 weeks of screening.
Oral corticosteroids (investigational or marketed) within 2 weeks of screening (unless on chronic stable dose for >3 months).
IA corticosteroid (investigational or marketed) in either knee within 3 months of screening.
IV or IM (Intramuscular) Corticosteroid injection (investigational or marketed) within 3 months of screening.
Any other IA drug/biologic use within 6 months of screening or 5 half-lives (whichever is longer) (e.g., hyaluronic acid, platelet-rich plasma (PRP) injection, stem cells, prolotherapy and amniotic fluid injection).
Any documented clinically significant degree of cognitive impairment or other condition, finding, or psychiatric illness at screening which, in the opinion of the investigator, could compromise subject safety.
Any condition other than OA of the knee which, in the opinion of the investigator, affects the ability to ambulate to a sufficient degree to interfere with the assessment of the safety and treatment effects of the study injection.
Participated in any interventional drug or device trial within 30 days prior to screening or concurrent participation in another research study that could complicate interpretation of the study findings.