What is the best medicine or injection for restoring joint function and relief pain of knee osteoarthritis?

Cortisone: Cortisone is the "gold standard". Other types of injections of forms of hyaluronic acid (the building block of joint cartilage) for "visco-supplementation" can be helpful. It is an "artificial joint juice".

Supplements: Start with good nutrition and try: glucosamine (500 mg 3x/ day), same (don't take if bipolar or with prostate cancer) 400 mg on empty stomach (may eventually take up to 800 mg 2x/ day) and must have b-complex with the same, and wait 2-3 months to see if these are helping. Both have good evidence for treating osteoarthritis and are safe. Physical therapy can help any misalignment in muscles.

Nutrition, supplem't: Start with good nutrition and try: glucosamine (500 mg 3x/ day), same (don't take if bipolar or with prostate cancer) 400 mg on empty stomach (may eventually take up to 800 mg 2x/ day) and must have b-complex with the same, and wait 2-3 months to see if these are helping. Both have good evidence for treating osteoarthritis and are safe. Physical therapy can help any misalignment in muscles.