The goal of this clinical trial is to evaluate the effectiveness of Neural Ice for pain management associated with knee osteoarthritis in adults aged 22-80 years. Participants will attend study visits and complete subject diaries. Participants will be followed for 6 months after study procedure.

Inclusion Criteria:

1. Age 22 to 80, inclusive of any gender
2. Baseline pain intensity of >/= 5 of the Numeric Rating Scale (NRS) despite current treatment Confidential Brixton Biosciences Inc. Page 12 of 53 Version: 1.1, 30 August 2024
3. Chronic symptomatic osteoarthritis of the knee (K-L stage 2, 3, or 4) on plain x-rays obtained within the previous 12 months
4. At least 3 months of previous conservative treatments (NSAID, acetaminophen, physical therapy, cortisone injections) that are not currently providing relief
5. Agree to see one doctor (study investigator) for knee pain during the study period
6. Willing/able to understand the informed consent form and provide written informed consent
7. Able to complete outcome measures (including electronic patient reported outcome measures)

Exclusion Criteria:

1. Known allergy to glycerol, hyaluronic acid, poloxamer 407, or phosphate buffered saline
2. History of cryoglobulinemia
3. History of cold-induced auto-immune hemolytic anemia (e.g. paroxysmal cold hemoglobinuria or cold agglutinin disease)
4. History of cold urticaria
5. History of Chilblain's (pernio) disease in the lower extremities
6. History of Raynaud's disease
7. Open and/or infected wounds or active tumor at or near the treatment site
8. History of vascular surgery involving femoral vessels on the injection side
9. History of surgical procedures to affected limb that, in the opinion of the investigator, could have impacted the integrity of the genicular nerves or blood vessels
10. Active bacterial or fungal infection that at the discretion of the investigator would preclude study participation
11. Currently taking >60 MME/day, as determined per MDcalc.com (opioid conversion calculator)
12. History of History of systemic inflammatory conditions such as rheumatoid arthritis
13. Bleeding disorders anticoagulant therapy, unless appropriately stopped or reversed for the procedure
14. Any condition or circumstance that would impact or confound assessment of safety and/or pain. For example, comorbid or concomitant pain conditions, pre-existing lower limb neurologic deficits, any psychiatric or neurologic disease
15. Cryoneurolysis, thermal or pulsed radiofrequency ablation, or phenol injection for the index knee within the past 12 months
16. Use of intra-articular injection of corticosteroid within the previous 3 months, or hyaluronic acid, prolotherapy, Confidential Brixton Biosciences Inc. Page 13 of 53 Version: 1.1, 30 August 2024 autologous blood, or platelet rich plasma injections for the index knee within the previous 6 months
17. Known contraindication to use of a regional anesthetic block
18. Pregnant, nursing or intent of becoming pregnant during the study period
19. Any condition (such as history of significant cardiovascular, renal failure/dialysis, hepatic or other systemic comorbidity/chronic pain condition) or circumstance that, in the opinion of the investigator, would compromise the safety of the subject or the quality of study data
20. Body habitus/knee anatomy that would preclude the use of the product injection needle size
21. Participation in any clinical study of a therapeutic investigational product within 30 days prior to enrollment
22. Unwilling to refrain from participation in any other clinical study through the duration of this study
23. Unwilling to refrain from any scheduled surgeries during the duration of this study