Patent ID: 6926739

Claim:
A prosthetic ankle joint device for articulating segments comprising: a first component ( 2 ) having a first articular bearing surface ( 5 ), the first component ( 2 ) adapted to engage a first tibial bone segment ( 11 ); a second component ( 3 ) having a second articular bearing surface ( 6 ) opposite to the first bearing surface ( 5 ) of the first component ( 2 ), the second component ( 3 ) adapted to engage a second tarsal bone segment ( 20 ); and a third component ( 4 ) interposed to the first ( 2 ) and the second component ( 3 ), having two articular third and fourth bearing surfaces ( 7 , 8 ) whose individual forms are complementary to said first and second articular surfaces ( 5 , 6 ) of the first ( 2 ) and of the second ( 3 ) components, said third and fourth articular bearing surfaces ( 7 , 8 ) being freely slidable, both in a sagittal plane and a frontal plane transverse to the sagittal plane, and individually non-captively engaged; said first articular bearing surface ( 5 ) and said second articular bearing surface ( 6 ) being both shaped not reproducing natural corresponding shapes of said articulating segments; the first and third ( 5 , 7 ) and the second and fourth ( 6 , 8 ) articular bearing surfaces being shaped complementarily and mutually to allow a non-fixed axis of rotation of the articulation to be reproduced while maintaining full congruence, wherein the first articular surface of said first component and the third articular surface of said third component complementary thereto are each shaped partly spherically with equal radii of curvature.