Htc evo 3d

I have a question, sprint will be discontinuing the evo 3d soon and will be sending it here to vm. My question is when and if vm actually get the evo would i be able to use an old evo 3d that i have from sprint or would i have to buy the vm one. what i really trying to say, is sprint just sending the evo to vm as is or are they revamping it. where as you cannot buy a used one like say of ebay and use it on vm. i don't know just was thinking about it and decided to ask here.