How To Reduce Painful Arthritis In Collar Bone?

hi, my mum suffers from realy bad arthritis in her collar bone after it was broken many years ago but nothin seems to help the pain she has had antiflamatory tablets which help for a while but nothing long term. she has been offered an injection into the bone but she doesnt like the idea of it is there anything else she can try. no pain relif is strong enough please help