Are injections for arthritis good?

I have steroid injections for my arthritis in my knee and shoulder. The problem is that the will only inject you once every six to twelve months or so. The injections work on some people but not on others, similarly it works on some arthritis but not others. It can take up to six weeks for the injection to "take". Speak to your GP or Consultant they are in the best position to guide you. I have had my injections on the NHS.