rotatory joint vs rotary joint

rotatory joint and rotary joint both are nouns.

Word	Noun	Adjective	Verb	Adverb
rotatory joint	Yes	No	No	No
rotary joint	Yes	No	No	No

As nouns, rotatory joint and rotary joint are synonyms defined as:

rotatory joint and rotary joint: a freely moving joint in which movement is limited to rotation

Other synonyms of rotatory joint include articulatio trochoidea, pivot joint.

rotatory joint (noun)	rotary joint (noun)
a freely moving joint in which movement is limited to rotation	a freely moving joint in which movement is limited to rotation