US 12,329,650 B2Granted

Artificial joint

AssigneeNipro Corporation

InventorsHitoshi Hirata, Shigeru Kurimoto, Shunsuke Notazawa, Yuto Otani

Life of this patent

Estimating the term…

Loading patent…

Abstract

An artificial joint is characterized by: having a first member including a caput part on which a prescribed curved surface is formed, and a second member including a fossa part having a surface which abuts the prescribed curved surface of the caput part; the second member being rotatable in a flexing direction of a joint with a prescribed point on the caput part being the center of rotation; and the prescribed curved surface of the caput part being defined by a curve which depicts a convex arc toward the side abutting the fossa part when the caput part is viewed from the axial direction of the rotation, and in which, when two arbitrary points are taken on the curve, the radius of curvature of the point positioned further toward the flexing side of the joint on the curve is smaller than the radius of curvature of the other point.

Claims11

Dependent claims

An artificial joint for a human body, the joint comprising:

a first member including a bone head portion, on which a predetermined curved surface is formed, and a first stem portion implantable in a first bone;
and
a second member including a bone fossa portion, which has a surface in contact with the predetermined curved surface of the bone head portion, and a second stem portion implantable in a second bone adjacent to the first bone, wherein
the second member is configured to pivot in bending and stretching directions of a joint about a predetermined point on the bone head portion as a rotation center, and
the predetermined curved surface of the bone head portion is defined by a curve that (i) is a convex arc toward a side abutting on the bone fossa portion when the bone head portion is viewed from an axial direction of pivoting movement, (ii) has, when two arbitrary points are taken on the curve, a curvature radius at a point located closer to a bending side of the joint on the curve which is smaller than a curvature radius at another point, and (iii) constitutes a part of a locus of a logarithmic spiral defined by a Fibonacci sequence.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/637,226Filed 21 Aug 2020
Priority: JP 2019-15204522 Aug 2019
Published: US 2022/0273444 A11 Sep 2022
Granted: 17 Jun 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

A61F 2/4241
For wrists or ankles; for hands, e.g. fingers; for feet, e.g. toes: for hands, e.g. fingers
A61F 2/38
Joints: for elbows or knees
A61F 2/385
Hinged, i.e. with transverse axle restricting the movement: also provided with condylar bearing surfaces
A61F 2/30767
Joints: special external or bone-contacting surface, e.g. coating for improving bone ingrowth