Problem having maimed another 50 inside (7)
I believe the answer is:
dilemma
'problem' is the definition.
(thesaurus)
'maimed another 50 inside' is the wordplay.
'another' indicates an anagram.
'50' becomes 'l' (roman numeral).
'inside' is an insertion indicator.
'maimed' is an anagram of 'diemma'.
'diemma' enclosing 'l' is 'DILEMMA'.
'having' is the link.
(Other definitions for dilemma that I've seen before include "23 [SPOT]" , "Difficult problem" , "Difficult decision" , "a problem for Shaw's doctor" , "Predicament" .)