Torture device, hence squad must bring in doctor (10)
I believe the answer is:
thumbscrew
'must bring in doctor' is the definition.
I can't judge whether this defines the answer.
'torture device hence squad' is the wordplay.
'torture device hence' becomes 'thumbs' (I am not sure about this - if you are sure you should believe this answer much more).
'squad' becomes 'crew' (crew is a kind of squad).
'thumbs'+'crew'='THUMBSCREW'
(Other definitions for thumbscrew that I've seen before include "That could be unpleasant!" , "Instrument of torture (crushing the pollex)" , "It puts the squeeze on" , "excruciating instrument" , "agonised by it?" .)