Representing transactional integrity in state diagram


I hope you can help. I need to model a system in which there is a “replaceable” object; i.e. an object where a new version can be created at a point in time (regardless of the state of the original) which supercedes the original object. It is important that the transition of the original to the final (immutable) state occurs within the same transaction as the creation of the replacement object. How can I represent this transactional integrity within a state chart? Is this even possible? Or should this be done using an activity diagram supporting the state charts?