I'm an American and I refer to a situation which is settled as "sorted out." My English family would just say that it's "sorted". Which is the earlier expression? Did Americans add the preposition or did the English drop it?
Sorted has a few specific meanings in British English that are extrapolations from the usual meaning of 'sort out', ie to put things in order. They are slang expressions and 'sort out' would still be preferable in formal or written English, although not for all the slang meanings below.
The slang meanings of 'sorted' are described by the Oxford Living Dictionaries:
sorted (adjective, British informal)
organized, arranged, or dealt with satisfactorily. 'And your social commitments?' 'They’re well sorted' | he's working on that old car he's been trying to get sorted
(of a person) confident, organized, and emotionally well balanced. after a while, you realize they're not as sorted as they seem | a pretty sorted kind of bloke
(of a person) prepared for or provided with something (especially illegal drugs)
@Henry mentioned the more menacing usage above, described by Oxford Living Dictionaries:
sort someone out (informal) Deal with a troublesome person, typically by reprimanding or punishing them: 'if he can't pay you, I'll sort him out'