Turn up and crumble — a Doctor will do this procedure (6,8)

I believe the answer is:

lumbar puncture

I'm a little stuck... Click here to teach me more about this clue!

'will do this procedure' is the definition.
The definition suggests a singular noun which matches the answer.

'turn up and crumble a doctor' is the wordplay.
'and' says to put letters next to each other.
'doctor' indicates anagramming the letters.
'turn'+'up'+'crumble'+'a'='turnupcrumblea'
'turnupcrumblea' anagrammed gives 'LUMBAR PUNCTURE'.

Can you help me to learn more?

I've seen this clue in The Hindu.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.