derangement vs disarticulation

derangement

noun
  • An act or instance of deranging. 

  • A permutation of a set such that no element is in its previous position. 

  • The property of being deranged. 

disarticulation

noun
  • The act of disarticulating. 

  • Some amputations: where a joint is disarticulated: e.g. knee, hip, elbow or shoulder disarticulation. 

How often have the words derangement and disarticulation occurred in a corpus of books? (source: Google Ngram Viewer )