How is the best way to treat bursitis in ac joint?

Anti-inflammatories : Ac joint pain is usually due to inflammation, either due to trauma or arthritis. Oral and/or injectable steroids are the fastest way to treat inflammation. Ice, rest and nsaid's ate also very helpful treatments, but may take a little longer to work. Sometimes therapy or even surgery may be needed. See a board certified orthopaedic surgeon for evaluation and treatment.

Bursitis: Try a nsaids drug. If no improvement a cortisone injection can help.