Well that was part of the explanation AGENTS OF S.H.I.E.L.D the T.V show gave for his resurrection.
Coulson: The surgeries worked Steve I’m alive.
Everyone: COULSON YOUR ALIVE!!(Massive Group huge, everyone lets go but Steve.)
Coulson: (to Steve) Lunch?
Steve: Sure (they go off chatting about baseball)
Natasha: Come on Clint we’re going to Vegas!
Clint: Yeah (they go both smiling)
Tony: Wait for us!! (Grabs Bruce they follow Clint and Natasha)
Thor: I think we need to talk to mother about this
Loki: Agreed (both leave for Asgard)
Fury: Well that worked out.
Maria Hill: DEAR!!
Fury: Coming! (Leaves)