Knee joint prosthesis
OwnerJosef Grafingerinventor
Life of this patent
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Abstract
The invention relates to a knee joint prosthesis comprising two arched guiding elements (3, 4) with a variable curvature in a first body (1) associated with the thigh, bolts (6, 7), or the like, of a second body (2) associated with the lower leg engaging in said guiding elements. The points XP(φ), YP(φ) of one guiding element (3) and the points XQ(φ) and YQ(φ) of the other guiding element (4) correspond approximately to the following equations: XP(φ)=A1×φ5+b1×φ4+C1×φ3+D1×φ2+E1×φ−F1; YP(φ)=A2×φ5+B2×φ4+C2×φ3+D2×φ2+E2×φ−F2; XQ(φ)=A3×φ5+B3×φ4+C3×φ3+D3×φ2+E3×φ−F3; YQ(φ)=A4×φ5+B4×φ4+C4×φ3+D4×φ2+E4×φ−F3, the deflection angle f of the knee joint being indicated in radians. The inventive knee joint prosthesis enables a significant adaptation to the natural movement.
Claims6
A knee joint prosthesis, characterised in that two arched guiding elements (3, 4) of variable curvature are provided in a first body (1), associated with the thigh, into which are engaged bolts (6, 7) or the like of a second body (2), associated with the lower leg, and the points XP(φ), YP(φ) of the one guiding element (3) and the points XQ(φ), YQ(φ) of the other guiding element (4) correspond approximately to the following equations:
- XP(φ)=A1×φ5+B1×φ4+C1×φ3+D1×φ2+E1×φ−F1
- YP(φ)=A2×φ5+B2×φ4+C2×φ3+D2×φ2+E2×φ−F2
- XQ(φ)=A3×φ5+B3×φ4+C3×φ3+D3×φ2+E3×φ−F3
- YQ(φ)=A4×φ5+B4×φ4+C4×φ3+D4×φ2+E4×φ−F4
- whereby the deflection angle φ of the knee joint is indicated in radians.
Dependencies are inferred from the claim text.