Prosthetic device for joints

• US 6,342,076 B1
• Filed: 07/16/1998
• Issued: 01/29/2002
• Est. Priority Date: 01/22/1996
• Status: Expired due to Fees

• Current Assignee: Handevelop AB
• Original Assignee: Handevelop AB
• Inventors: Lundborg, Göran
• Primary Examiner(s): Snow, Bruce
• Application Number:
  US09/116,262
• Time in Patent Office: 1,293 Days
• Field of Search: 623/17, 623/18, 623/21, 623/20, 623/21.11, 623/21.12, 623/21.14, 623/21.15
• US Class Current: 623/21.15
• CPC Class Codes: A61F 2/30742 Bellows or hose-like seals; Sealing membranes A61B17/8808 takes precedence; sealing membranes for retaining bone substitute A61F2/2846
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/4225 for feet, e.g. toes
• CPC Class Codes: A61F 2/4241 for hands, e.g. fingers
• CPC Class Codes: A61F 2/4261 for wrists
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2002/30004 the prosthesis being made from materials having different values of a given property at different locations within the same prosthesis
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30118 concentric circles
• CPC Class Codes: A61F 2002/3013 figure-"8"- or hourglass-shaped
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30354 Cylindrically-shaped protrusion and recess, e.g. cylinder of circular basis
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2002/30565 having spring elements
• CPC Class Codes: A61F 2002/30568 Multiple spring systems including two or more helical springs
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/4243 for interphalangeal joints, i.e. IP joints
• CPC Class Codes: A61F 2002/4251 for metacarpo-phalangeal joints, i.e. MCP or MP joints, e.g. knuckle joints
• CPC Class Codes: A61F 2002/4258 : for trapezo-metacarpal joints of thumbs
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2220/0058 : soldered or brazed or welded
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/001 : Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2250/0014 : having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures

Abstract

In a prosthetic device for joints for implantation in humans and animals, a joint body is arranged between two fixing elements which are intended to be connected to adjoining bone parts. The joint body includes at least one essentially helical spring, and the ends of each spring are connected to the fixing elements.

Claims

1. A prosthetic device as a replacement for knuckle joints, intermediate and outer joints of fingers, and wrist joints of the fingers and hands for implantation in humans and animals, the device comprising:

two fixing elements which are each adapted to be connected to adjoining bone parts; and

a joint body arranged between the two fixing elements, the joint body consisting essentially of two essentially helical springs, each essentially helical spring having opposite ends and extending in a longitudinal direction of the joint body, the opposite ends of each of the two essentially helical springs being connected to the fixing elements,

wherein at least one of interference between the two essentially helical springs and tension in the two essentially helical springs limits the joint body to bending substantially only in a single plane.

2. A prosthetic device as claimed in claim 1, wherein the two essentially helical springs differ from each other in respect of one or more of length, winding cross-section, pitch, pitch angle, and wire cross-section.

3. A prosthetic device for joints as claimed in claim 2, wherein one or more of the two essentially helical springs is at least one of convex and concave in its longitudinal direction.

4. A prosthetic device for joints as claimed in claim 2, wherein the joint body consists essentially of two parallel cylindrical springs in a plane extending perpendicular to a plane of bending of the joint body.

5. A prosthetic device for joints as claimed in claim 1, wherein each spring is one of a tension spring and a compression spring.

6. A prosthetic device for joints as claimed in claim 5, wherein one or more of the two essentially helical springs is at least one of convex and concave in its longitudinal direction.

7. A prosthetic device for joints as claimed in claim 5, wherein the joint body consists essentially of two parallel cylindrical springs in a plane extending perpendicular to a plane of bending of the joint body.

8. A prosthetic device for joints as claimed in claim 1, wherein one or more of the two essentially helical springs is cylindrical in its longitudinal direction.

9. A prosthetic device for joints as claimed in claim 8, wherein the joint body consists essentially of two parallel cylindrical springs in a plane extending perpendicular to a plane of bending of the joint body.

10. A prosthetic device for joints as claimed in claim 1, wherein one or more of the two essentially helical springs is at least one of convex and concave in its longitudinal direction.

11. A prosthetic device as claimed in claim 1, wherein one of the two essentially helical springs is essentially concentrically arranged inside a bigger one of the two essentially helical springs.

12. A prosthetic device as claimed in claim 1, wherein one or more of the two essentially helical springs has a wire surface coated with a biocompatible material.

13. A prosthetic device for joints as claimed in claim 1, wherein the joint body extends between and joins the two fixing elements, and each fixing element includes a base plate arranged in a plane extending essentially perpendicular to the longitudinal direction of the joint body, the base plate having a surface connected to one end of the joint body, and a fixing means connected to surface of the base plate opposite the surface to which the joint body is connected, the fixing means projecting essentially in the longitudinal direction of the joint body, the fixing means being adapted to be connected to an anchoring means in an adjoining bone part.

14. A prosthetic device for joints as claimed in claim 8, wherein the surface of the base plate which is connected to the joint body is designed such that the two essentially helical springs, when in a resting position, are arcuate in the longitudinal direction of the joint body.

15. A prosthetic device for joints as claimed in claim 8, wherein fixing means projects from the base plate at an angle in relation to the longitudinal direction of the joint body.

16. A prosthetic device for joints as claimed in claim 8, wherein each of the two essentially helical springs has windings, the windings of each spring closest to an associated base plate being supported by a structure projecting from the base plate.

17. A prosthetic device for joints as claimed in claim 1, wherein the joint body consists essentially of two parallel cylindrical springs in a plane extending perpendicular to a plane of bending of the joint body.

18. A prosthetic device for joints as claimed in claim 1, wherein the joint body includes a combination of tension and compression springs.

19. A prosthetic device for joints as claimed in claim 1, wherein one or more of the two essentially helical springs is enclosed by a biocompatible material.

20. A prosthetic device for joints as claimed in claim 1, wherein the joint body consists essentially of the two essentially helical springs arranged substantially parallel to one another and extending in a longitudinal direction of the joint body, ends of each spring being connected to the fixing elements.