Terminal state of a work item..

I am interested in a terminal state of a work item after which no changes are allowed to the work item. For example, no one should be able to add comments... change attributes.. attach change set..etc. In order to do any of that, I would expect the user to reopen the work item first and then be able to carry out what they are trying to do. I have been looking at triggers..etc. but nothing jump at me directly.

any suggestions?

Thanks.