rotule angolul

kneecap [kneecaps]▼◼◼◼(bone)
noun
[UK: ˈniːkæp] [US: ˈniːˌkæp]

joint [joints]▼◼◼◼(joint with freedom to rotate)
noun
[UK: dʒɔɪnt] [US: ˌdʒɔɪnt]

ball-and-socket joint▼◼◻◻(type of joint)
noun
[UK: bɔːl ənd ˈsɒkɪt dʒɔɪnt] [US: ˈbɒl ænd ˈsɑːkət ˌdʒɔɪnt]