'arthrostomy' originates from Modern New Latin/medical coinage, formed from Greek elements 'arthro-' and '-stomy' (via New Latin 'arthrostomia'), where 'arthro-' meant 'joint' and 'stoma/-stomy' meant 'mouth' or 'opening'.

'arthrostomy' was formed in medical New Latin from the Greek roots 'arthro-' (joint) + 'stoma'/'-stomy' (opening). It entered English as a technical surgical term constructed from these elements rather than evolving from a single older English word.

Initially the roots literally meant 'joint' + 'opening (mouth)'; the assembled medical term came to mean specifically 'the surgical creation of an opening into a joint' in modern usage.