Certain about you French Germany stitched up (7)
I believe the answer is:
sutured
'stitched up' is the definition.
(I've seen this before)
'certain about you french germany' is the wordplay.
'certain' becomes 'sure' ('sure' can be a synonym of 'certain').
'about' is an insertion indicator.
'you french' becomes 'tu' (I've seen this in other clues).
'germany' becomes 'd' (international vehicle registration code).
'sure' enclosing 'tu' is 'suture'.
'suture'+'d'='SUTURED'
(Other definitions for sutured that I've seen before include "stitched up" , "Rust due {anag.)" .)