This study is testing a treatment called Allocetra-OTS for people with severe knee osteoarthritis, a condition where the knee joint wears down, causing pain and difficulty moving. We want to see if Allocetra-OTS is safe and if it might help. If you join, you must be 18 or older, have knee osteoarthritis confirmed by X-ray, and be scheduled for or offered surgery. You also need to have good blood tests and be able to follow the study rules. If you have an infection near your knee, had knee replacement surgery, or have other major health problems, you cannot participate. You also cannot join if you're in another study or if your doctor advises against it. If you are pregnant or have certain other health issues, you cannot take part.

• The study is a pilot, meaning it’s a small and first-time test.
• You must be willing to follow study procedures and attend follow-ups.
• Participants cannot have had recent knee surgery or other major health issues.