Keen to wreck the joint (4)

I believe the answer is:

knee

'the joint' is the definition.
(knee is a kind of joint)

'keen to wreck' is the wordplay.
'to wreck' indicates anagramming the letters.
'keen' is an anagram of 'KNEE'.

(Other definitions for knee that I've seen before include "Where the femur meets the tibia" , "Leg?joint" , "It jerks reactively" , "Flexible joint" , "One has a cap" .)

I've seen this clue in The Guardian and The Telegraph.

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