US 12,329,650 B2
Artificial joint
Hitoshi Hirata, Nagoya (JP); Shigeru Kurimoto, Nagoya (JP); Shunsuke Notazawa, Osaka (JP); and Yuto Otani, Osaka (JP)
Assigned to NIPRO CORPORATION, Osaka (JP)
Appl. No. 17/637,226
Filed by Hitoshi Hirata, Nagoya (JP); Shigeru Kurimoto, Nagoya (JP); and NIPRO CORPORATION, Osaka (JP)
PCT Filed Aug. 21, 2020, PCT No. PCT/JP2020/031566
§ 371(c)(1), (2) Date Feb. 22, 2022,
PCT Pub. No. WO2021/033761, PCT Pub. Date Feb. 25, 2021.
Claims priority of application No. 2019-152045 (JP), filed on Aug. 22, 2019; and application No. 2019-152093 (JP), filed on Aug. 22, 2019.
Prior Publication US 2022/0273444 A1, Sep. 1, 2022
Int. Cl. A61F 2/42 (2006.01); A61F 2/38 (2006.01); A61F 2/30 (2006.01)
CPC A61F 2/4241 (2013.01) [A61F 2/38 (2013.01); A61F 2/385 (2013.01); A61F 2002/30158 (2013.01); A61F 2/30767 (2013.01); A61F 2002/30935 (2013.01); A61F 2002/4251 (2013.01)] 11 Claims
OG exemplary drawing
 
1. 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.