Popular edition getting everything topsy-turvy (9)
I believe the answer is:
inversion
'getting everything topsy-turvy' is the definition.
(the process of inverting or turning upside down)
'popular edition' is the wordplay.
'popular' becomes 'in'.
'edition' becomes 'version'.
'in'+'version'='INVERSION'
(Other definitions for inversion that I've seen before include "turning around" , "The opposite of" , "upsetting change" .)