A vehicle broke his leg (6)
I believe the answer is:
sleigh
'a vehicle' is the definition.
(sleigh is a kind of vehicle)
'broke his leg' is the wordplay.
'broke' is an anagram indicator.
'his'+'leg'='hisleg'
'hisleg' anagrammed gives 'SLEIGH'.
(Other definitions for sleigh that I've seen before include "Santa's transport" , "Toboggan" , "Vehicle for transport over snow" , "ice, you say, in the Rockies?" , "Carriage to run on snow" .)