How do I know if joint fluid therapy may be a good option to treat my arthritis?

Get evaluated. In my practice. A patient that does not respond to corticosteroid injections in the knees and is not a candidate for arthroscopy or joint replacement of the knees due to age or health, may be a candidate for synvisc (hylan g-f 20) or similar injections. Properly performed, and assuming no allergy to the product contents, the injections may provide substantial improvement in symptom and activity levels.
See a Doc. I assume you are talking about hyaluronic acid injections which is a jelly like clear substance that is approved for moderate osteoarthritis. The only way to tell is to have an evaluation with a physician who administers these shots and they will be able to tell you if you are a good candidate for them.
Exercise caution. Our joint spaces are closed spaces: sequestered, hidden from "view" from even our own bloodstream (much like a similar closed space: the eyeball). A certain amount of caution is warranted so as not to create openings to these joint spaces. Certain types of arthritis are "autoimmune", and represent the "foreign" nature of joint spaces even to our own immune systems. Best to leave them alone.