Surgery twisted bones to save pair of joints (4,3)
I believe the answer is:
nose job
'surgery' is the definition.
(nose job is a kind of surgery)
'twisted bones to save pair of joints' is the wordplay.
'twisted' indicates an anagram.
'to save' means one lot of letters goes inside another.
'pair of joints' becomes 'jo' (I can't explain this - if you can you should give a lot more credence to this answer).
'bones' with letters rearranged gives 'noseb'.
'noseb' placed around 'jo' is 'NOSE JOB'.
Can you help me to learn more?
(Other definitions for nose job that I've seen before include "Surgery of the face" , "Piece of plastic surgery" , "Rhinoplasty" , "Unfortunately" , "Facial operation" .)