human knee vs genu

human knee and genu both are nouns.

Word	Noun	Adjective	Verb	Adverb
human knee	Yes	No	No	No
genu	Yes	No	No	No

As nouns, human knee and genu are synonyms defined as:

human knee and genu: hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella

Other synonyms of human knee include articulatio genus, knee, knee joint.

human knee (noun)	genu (noun)
hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella	hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella