Artificial bone joint

Claim 2

An artificial bone joint for joining first and second bones comprising: a first member including a first elongated anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a first direction, and including a first sliding portion having a convex curved surface; a second member including a second elongated anchor portion having a proximal end, a distal end, and a second central longitudinal axis extending from said proximal end to said distal end in a second direction, and including a second sliding portion having a concave curved surface for pivotally engaging said convex surface; said first anchor portion including a plurality of axially spaced first recesses forming at least one pair of first anchor bosses symmetrically opposed to each other about said first central longitudinal axis having perimetrical surfaces defining a maximum cross-sectional area of the first anchor portion and each of said first recesses having a proximal end wall defined by a radially extending surface transverse to the longitudinal axis and a bottom surface inclined from a proximal to distal direction at a first angle of less than 90° with the proximal end wall to form a catching structure for said first member; and said second anchor portion including a plurality of axially spaced second recesses forming at least one pair of second anchor bosses symmetrically opposed to each other about said second central axis having perimetrical surfaces defining a maximum cross-sectional area of the second anchor portion and each of said second recesses having a proximal end wall defined by a radially extending surface transverse to the longitudinal axis and a bottom surface inclined from a proximal to distal direction at a first angle of less than 90° with the proximal end wall to form a catching structure for said second member.

Claim 3

An artificial bone joint according to claim 1, wherein each sad recess is semielliptical in cross section.

Claim 4

An artificial bone joint for joining first and second bones comprising: a first member including a first elongated anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a first direction, and including a first sliding portion having a convex curved surface; a second member including a second elongated anchor portion having a proximal end, a distal end, and a second central longitudinal axis extending from said proximal end to said distal end in a second direction, and including a second sliding portion having a convex curved surface for pivotally engaging said convex surface; said first anchor portion including a plurality of axially spaced first recessed forming at least one pair of first anchor bosses symmetrically opposed to each other about said first central longitudinal axis having perimetrical surfaces defining a maximum cross-sectional area of the first anchor portion and each of said first recessed having a proximal end wall defined by a radially extending surface transverse to the longitudinal axis and a bottom surface inclined from a proximal to distal direction at a first angle of less than 90° with the proximal end wall to form a catching structure for said first member; and said second anchor portion including a plurality of axially spaced second recessed forming at least one pair of second anchor bosses symmetrically opposed to each other about said second central axis having perimetrical surfaces defining a maximum cross-sectional area of the second anchor portion and each of said second recesses having a proximal end wall defined by a radially extending surface transverse to the longitudinal axis and a bottom surface inclined from a proximal to distal direction at a first angle of less than 90° with the proximal end wall to form a catching structure for said second member; wherein each said anchor boss has a shape of a parallelogram in cross section.

Claim 5

An artificial bone joint for joining first and second bones comprising: a first member including a first elongated anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a first direction, and including a first sliding portion having a convex curved surface; a second member including a second elongated anchor portion having a proximal end, a distal end, and a second central longitudinal axis extending from said proximal end to said distal end in a second direction, and including a second sliding portion having a convex curved surface for pivotally engaging said convex surface; said first anchor portion including a plurality of axially spaced first recessed forming at least one pair of first anchor bosses symmetrically opposed to each other about said first central longitudinal axis having perimetrical surfaces defining a maximum cross-sectional area of the first anchor portion and each of said first recessed having a proximal end wall defined by a radially extending surface transverse to the longitudinal axis and a bottom surface inclined from a proximal to distal direction at a first angle of less than 90° with the proximal end wall to form a catching structure for said first member; and said second anchor portion including a plurality of axially spaced second recessed forming at least one pair of second anchor bosses symmetrically opposed to each other about said second central axis having perimetrical surfaces defining a maximum cross-sectional area of the second anchor portion and each of said second recesses having a proximal end wall defined by a radially extending surface transverse to the longitudinal axis and a bottom surface inclined from a proximal to distal direction at a first angle of less than 90° with the proximal end wall to form a catching structure for said second member; wherein each said anchor boss has a shape of a parallelogram in cross section.

Claim 6

An artificial bone joint according to claim 1, wherein said first and second anchor portions each have substantially square cross-sections.

Claim 7

An artificial bone joint according to claim 1, wherein said first and second angles are between about 45° and about 90° .

Claim 8

An artificial bone joint according to claim 4, wherein said first and second angles are between about 45° and about 90° .

Claim 9

An artificial fixed bone joint for joining first and second bones comprising: an elongated substantially V-shaped member having a first elongated anchor portion having first and third ends opposite to each other and a first central longitudinal axis extending from said third end to said first end; and a second elongated anchor portion having second and fourth ends opposite to each other and a second central longitudinal axis extending from said fourth end to said second end, said second portion being attached at said fourth end to said third end of said first portion, said first and second axis forming a fixed angle of less than 180 degrees; said first anchor portion having first and third surfaces diametrically opposite to each other, said first and third surfaces extending from said first end to said third end, said second anchor portion having second and fourth surfaces diametrically opposite to each other, said second and fourth surfaces extending from said second end to said fourth end, said first and second surfaces being substantially continuouslly even, said third and fourth surfaces facing each other; at least one first substantially wedge-shaped recess formed in the third surface, each first recess forming a first boss having a boss surface facing said first end and defining one end of said first recess, said first boss surface forming an angle of less than 100 degrees with the first axis to form a catching structure for said third surface; and at least one second substantially wedge-shaped recess formed in the fourth surface, each second recess forming a second boss having a boss surface facing said second end and defining one end of said second recess, said second boss surface forming an angle of less than 100 degrees with the second axis to form a catching structure for said fourth surface.

Claim 10

An artificial fixed bone joint for joining first and second bones comprising: an elongated substantially V-shaped member having a first elongated anchor portion having first and third ends opposite to each other and a first central longitudinal axis extending from said third end to said first end; and a second elongated anchor portion having second and fourth ends opposite to each other and a second central longitudinal axis extending from said fourth end to said second end, said second portion being attached at said fourth end to said third end of said first portion, said first and second axis forming a fixed angle of less than 180 degrees; said first anchor portion having first and third surfaces diametrically opposite to each other, said first and third surfaces extending from said first end to said third end, said second anchor portion having second and fourth surfaces diametrically opposite to each other, said second and fourth surfaces extending from said second end to said fourth end, said first and second surfaces being substantially continuouslly even, said third and fourth surfaces facing each other; at least one first substantially wedge-shaped recess formed in the third surface, each first recess forming a first boss having a boss surface facing said first end and defining one end of said first recess, said first boss surface forming an angle of less than 100 degrees with the first axis to form a catching structure for said third surface; and at least one second substantially wedge-shaped recess formed in the fourth surface, each second recess forming a second boss having a boss surface facing said second end and defining one end of said second recess, said second boss surface forming an angle of less than 100 degrees with the second axis to form a catching structure for said fourth surface.

Claim 11

The artificial bone joint according to claim 7, wherein said first and second members comprise approximately 80% tetragonal zirconia and approximately 20% cubic zirconia and have a bend resistant strength of 130 Kg/mm 2 .

Claim 12

An artificial bone joint for joining first and second bones comprising: a first member including a first anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a first direction, and including a first sliding portion having a convex curved surface having a substantially semicylindrical shape and a plane side surface abutting said proximal end of said first anchor portion and having a groove formed in the convex curved surface; and a second member including a second anchor portion and including a second sliding portion having a concave curved surface substantially in a form of a pentagon and having a boss formed on the concave curved surface, wherein the concave curved surface is in sliding contact with said convex curved surface; wherein said first central longitudinal axis forms ann angle in a range from about 5 degrees to about 15 degrees with the direction perpendicular to the plane side surface.

Claim 13

An artificial bone joint for joining first and second bones comprising: a first member including a first anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a first direction, and including a first sliding portion having a convex curved surface having a substantially semicylindrical shape and a plane side surface abutting said proximal end of said first anchor portion and having a groove formed in the convex curved surface; and a second member including a second anchor portion and including a second sliding portion having a concave curved surface substantially in a form of a pentagon and having a boss formed on the concave curved surface, wherein the concave curved surface is in sliding contact with said convex curved surface; wherein said first central longitudinal axis forms ann angle in a range from about 5 degrees to about 15 degrees with the direction perpendicular to the plane side surface.

Claim 14

An artificial bone joint according to claim 1, wherein said convex curved surface has a substantially semicylindrical shape and a plane side surface abutting said proximal end of said first anchor portion and wherein said first direction forms an angle in a range from about 5 degrees to about 15 degrees with a direction perpendicular to the plane side surface.

Claim 15

An artificial bone joint according to claim 10, wherein each of said first recess and said second recess forms a second concave surface.

Claim 16

An artificial bone joint for joining first and second bones comprising: a first member including a first elongated anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a first direction, and including a first sliding portion, said first sliding portion having a convex curved surface substantially of a semicylindrical shape, a groove formed in the convex curved surface, and a first plane surface extending perpendicularly to the first direction, said first plane surface being for abutment contact with an end surface of the first bone; a second member including a second elongated anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a second direction, and including a second sliding portion, said second sliding portion having a first concave surface substantially in a form of a pentagon, a limiting boss formed on the first concave surface, and a second plane surface extending perpendicularly to the second direction, said second plane surface being for abutment contact with an end surface of the second bone, the first concave surface being in sliding contact with and pivotally engaging said convex curved surface; and limiting means inserted into said groove for limiting an angle of flexion and extension of the joint; wherein said joint further includes a first anchor portion on said first member and including at least one first axially extending recess forming a first anchor boss having a first axially extending perimetrical surface defining a maximum cross-sectional area of said first anchor portion and a first radially extending surface facing said first direction at one end of said first recess, said first radially extending surface forming an angle of less than 100° with the first direction to form a first catching structure for said first member; and a second anchor portion on said second member and including at least one second axially extending recess forming a second anchor boss having a second axially extending perimetrical surface defining a maximum cross-sectional area of said second anchor portion and a second radially extending surface facing said second direction at one end of said second recess, said second radially extending surface forming an angle of less than 100 ° with the second direction to form a second catching structure for said second member.

Claim 17

An artificial bone joint for joining first and second bones comprising: a first member including a first elongated anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a first direction, and including a first sliding portion, said first sliding portion having a convex curved surface substantially of a semicylindrical shape, a groove formed in the convex curved surface, and a first plane surface extending perpendicularly to the first direction, said first plane surface being for abutment contact with an end surface of the first bone; a second member including a second elongated anchor portion having a proximal end, a distal end, and a first central longitudinal axis extending from said proximal end to said distal end in a second direction, and including a second sliding portion, said second sliding portion having a first concave surface substantially in a form of a pentagon, a limiting boss formed on the first concave surface, and a second plane surface extending perpendicularly to the second direction, said second plane surface being for abutment contact with an end surface of the second bone, the first concave surface being in sliding contact with and pivotally engaging said convex curved surface; and limiting means inserted into said groove for limiting an angle of flexion and extension of the joint; wherein said joint further includes a first anchor portion on said first member and including at least one first axially extending recess forming a first anchor boss having a first axially extending perimetrical surface defining a maximum cross-sectional area of said first anchor portion and a first radially extending surface facing said first direction at one end of said first recess, said first radially extending surface forming an angle of less than 100° with the first direction to form a first catching structure for said first member; and a second anchor portion on said second member and including at least one second axially extending recess forming a second anchor boss having a second axially extending perimetrical surface defining a maximum cross-sectional area of said second anchor portion and a second radially extending surface facing said second direction at one end of said second recess, said second radially extending surface forming an angle of less than 100 ° with the second direction to form a second catching structure for said second member.

Claim 18

An artificial bone joint according to claim 12, wherein said first sliding portion has two vertical surfaces space from said second member wherein said two vertical surfaces lie in different planes and are joined by a slant surface formed at an angle of approximately 45° from horizontal.

Claim 19

An artificial bone joint according to claim 10 wherein said first member has at least one rounded corner having a radius of curvature of approximately 2.5 mm.

Claim 20

An artificial bone joint according to claim 10, wherein said convex curved surface has a center and wherein said groove is an arcuate groove cut in the center of said convex curved surface, having a substantially a rectangular shape in cross section, and terminating at end walls positioned at each longitudinal end of the arcuate groove.

Claim 21

An artificial bone joint according to claim 12, wherein said limiting boss is positioned toward an apex of said first concave surface, has a substantially rectangular shape, and has a second concave surface which is spaced from said first concave surface and which is substantially parallel to said first concave surface.

Claim 22

An artificial bone joint of claim 1, wherein the convex curved surface is substantially of a semicylindrical shape and the concave curved surface is in a form of a pentagon.

Claim 23

An artificial bone joint of claim 17, further comprising means for limiting an angle of flexion and extension of the joint, said angle limiting means including a groove formed in the convex curved surface and a limiting boss formed on the concave curved surface, wherein the concave curved surface is in sliding contact with the convex curved surface.

Claim 24

The artificial bone joint of claim 18, wherein the first sliding portion further comprises a first plane surface extending perpendicularly to the first direction, said first plane surface being for abutment contact with an end surface of the first bone, and wherein the second sliding portion further comprises a second plane surface extending perpendicularly to the second direction, said second plane surface being for abutment contact with an end surface of the second home.

Claim 25

An artificial bone joint according to claim 17, wherein said first sliding portion has two vertical surfaces spaced from said second member wherein said two vertical surfaces lie in different planes and are joined by a slant surface formed at an angle of approximately 45 degrees from horizontal.

Claim 26

An artificial bone joint according to claim 17, wherein said first sliding portion has at least one rounded corner having an arcuate surface having a radius of approximately 2.5 mm.

Claim 27

An artificial bone joint according to claim 17, including a groove formed in said convex curved surface, wherein said convex curved surface has a center and wherein said groove is an arcuate groove cut in thee center of said convex curved surface, having a substantially rectangular shape in cross section, and terminating at end walls positioned at each longitudinal end of the arcuate groove.

Claim 28

An artificial bone joint according to claim 17, including a limiting boss formed on said concave curved surface, wherein said limiting boss is positioned toward ann apex of aid concave curved surface, has a substantially rectangular shape, and has a second concave surface which his spaced from said concave curved surface and which is substantially parallel to said concave curved surface.