This is an injection of medicine into the knee joint. It lubricates your knee so the bones can glide smoothly. It can help lessen the pain of arthritis.
To begin, the doctor numbs your knee with local anesthetic. Then, a needle is inserted through the numbed area. The doctor guides the needle with a video x-ray device called a "fluoroscope."
When the needle is inside the joint, the doctor injects the medicine. It's a gel-like fluid. It supplements your synovial fluid. That's the natural fluid in your knee that lubricates the joint. The medicine will help your joint move more smoothly. And that should reduce your pain.
When the injection is done, the needle is removed and your knee is bandaged. You may not feel relief for a few weeks. You may need to have more than one injection over series of visits to get the full benefit of the medicine.