KNEE PROSTHESIS

摘要

A knee prosthesis for a knee joint with a medial ball- like femoral condyle and with a width "w" is characterized on the lateral compartment by: - a trace-line "Lt1" of contact points "Pt1" for the tibia component (2) as a predetermined curve (15 ) on a spherical surface "Sc1", which has its centre at the centre Mb of the medial ball 1 and which has a radius in the range "Rc1" = 0,65 w +/- 0,25 w - a trace-line "Lt2" of common contact points "Pt2" at given flexion angles ? for a similar spherical surface "Sc2" attached to the femoral component with radius "Rc2"= Rc1, whereby at a given flexion angle ? there exists a plane "E1" through the centre Mb and the common contact point Pt1/Pt2, which contains the same guiding curves "Bi", "Be" on the tibial and on the femoral components, "Bi" towards medial and "Be" towards lateral, both of which stay in a geometrically fixed relation to the common contact point Ptl/Pt2, and - guiding curves "Bi" and "Be", which generate an enforced gliding and rolling movement in both directions.